Copyright 2023

Is MCS real? 



MCS  =  Multiple Chemical Sensitivity

TILT = Toxic-Induced Loss of Tolerance 


Multiple chemical sensitivity (MCS) is sometimes referred to as environmental illness, total allergy syndrome, sick building syndrome, chemical intolerance, chemical hypersensitivity, or idiopathic environmental intolerance.  It is a condition where a person becomes intolerant of many chemicals and in low doses.MCS is sometimes called TILT. Many MCS have mold sickness as well. The following information is a work in progress just like our understanding of this disease.

MCS is, unfortunately, very real. It is chronic, it is progressive, and it can start suddenly from the smallest of exposures. For those who are predisposed, or people triggered by doses of various chemicals, it often becomes disabling.

Many common chemical compositions can be poisonous to the MCS person. From perfume to new carpet or insulation, MCS is treatable only by removing oneself from these chemical exposures. This can seem impossible when it is something in the new house or car you just bought. The enormity of living with MCS is hard for the non-affected person to grasp. For many MCS afflicted it is not only the organs shutting down or the extreme pain and/or discomfort but it can sometimes cause complete upheaval from their home, career, family, and friends…

Every day we discover that some chemical causes health issues we did not know about. The average neighborhood can have as many as 60,000 chemicals in use all over and in different combinations. Only a small percentage of these are tested for long term or combined human toxicity. The majority of man-made chemicals and off-gassing vapor causing products were introduced over the last 75 years but the extreme combinations have only happened over the last 40 years. The MCS person begins to react extremely bad as their chemical sensitivity is 1000 times greater than average. For these reasons the MCS community may continue to grow at a rapid rate and it must be taken seriously.

MCS can become a fully debilitating condition. A sufferer is told by a doctor that they cant find anything wrong and from that point on the person tries their best to hide the pain. Individuals experience any range of symptoms when exposed to miniscule levels of various chemical substances or molds. Over times the symptoms, and the person’s ability to sense a problem is in the air, increase. Skin disorders, stomach issues, body pain and headaches, respiratory problems and even organ disfunctions are all common symptoms. As the disease progresses a person becomes more sick, more easily, and to an ever-increasing group of chemicals that each cause different symptoms. For this reason, the symptoms and cause of MCS differ from person to person.

The MCS patient who is not able to remove themselves from most chemicals experiences an ever growing number of issues to an ever increasing number of chemicals. Symptoms include some combination of most of the following:

Respiratory: Coughing, wheezing, shortness of breath, chest tightness, sinus congestion, and sore throat.

Neurological: Sudden headaches, migraines, dizziness, lightheadedness, difficulty concentrating, memory problems, brain fog, poor decision making capabilities and confusion that can get better after some time away from the chemical causes.

Skin: Rashes, itching, eczema of the skin, eczema of the eyes, body redness, hives, and other reactions.

Gastrointestinal: Abdominal pain, bloating, diarrhea, digestive disturbances, nausea

Fatigue and weakness: Often excessively tired or weak, even after adequate rest.

Musculoskeletal symptoms: Joint pain, muscle aches, and stiffness.

Sensitivity to odors, with sometimes severe and/or dangerous reactions, to fragrances, cleaning products, perfumes, and other chemical smells. Chemicals that can be smelled by everyone can potentially kill an MCS person that is highly reactive and cannot be removed from exposure.

Eye and vision problems: Eye irritation, burning, watery eyes, and blurred vision caused by eye eczema.

Cardiovascular symptoms: Palpitations, rapid heartbeat, and chest discomfort.

Emotional and psychological symptoms: Anxiety, depression, fear, irritability, mood swings, and emotional instability. These can be directly chemically caused but more often they are the result of the trauma that comes from having this disease.

Over time the exposures can cause life threatening issues like pancreas irregularity and/or failure, kidney function reduction or failure, sweat gland function reduction or failure, and/or other extreme allergic and/or anaphylactic attacks.

Most people will experience headaches or migraines triggered by some chemical sensitivity in their environment at some point in their lives. This is not MCS. Those afflicted with MCS experience triggers with many common chemicals, with a multitude of symptoms, every moment they are exposed and usually for days or weeks after they are exposed, eventually to a level that is more and more disabling.

MCS victims are possibly 1000 times more sensitive to chemicals than would make the average person sick. This makes the MCS person appear to be overreacting or dramatizing when in fact they often hide the extremity of their symptoms from others because it can be impossible for even them to understand or explain.

Sadly, the incidences and catastrophic levels of MCS are growing. About 4% of the world’s population has some level of known and identified chemical intolerance. It is likely that it affects over 25% of the total population in some way and has some form of common chemical induced reactions even though it may not yet be recognized by the sufferer. Those that currently have full, severe, and debilitating MCS are likely less than half of one percent of the total populations however this number is now growing at an alarming rate. 

Every person has a individual level of chemical toxin load they can take. Some have enough reactions to be called CS or chemical sensitive. An MCS person’s tolerance can be zero and it can be caused by an ever growing number of chemicals. For some it starts with petroleum, insecticides or other chemical man-made products. An MCS person can see their tolerance go up somewhat, over time, through detoxification and avoidance, but additional exposures immediately impact health. 

So why now? Well over the past 70 years almost everything natural has been replaced with synthetic. Fragrances that were made from flowers are now a mix of mostly unregulated chemical mixes and not regulated at all in their mixtures. 

So how do we diagnose it? There are no blood, chemical or scans that can directly diagnose the reactions that all MCS patients have. If you feel you may suffer from this disease, you can start with these Q&A tests: https://tiltresearch.org/qeesi-2/

MCS is sometimes called TILT. Much of what is known as TILT has mostly consolidated under the MCS (Multiple Chemical Sensitivity) name, but MCS (Multiple Chemical Sensitivity) and TILT (Toxicant-Induced Loss of Tolerance) are two related but distinct conditions that involve heightened sensitivity to chemical exposures. While they share some similarities, MCS primarily focuses on the sensitivity to chemicals, where individuals experience symptoms after exposure to various environmental triggers, including perfumes, cleaning products, pesticides, and other substances. The symptoms associated with MCS can affect multiple body systems. TILT is a broader term that encompasses not only sensitivity to chemicals but also other environmental triggers, such as electromagnetic fields, molds, and certain foods. TILT is characterized by the loss of tolerance to these triggers, leading to a range of symptoms that can resemble MCS. In addition to the symptoms associated with MCS, individuals with TILT may also experience symptoms like light sensitivity, intolerance to noise, and sensitivities to non-chemical triggers. MCS and TILT can affect all the organs however it is the brain, kidneys, skin and sweat glands usually first affected. Many MCS patients will see their condition grow into what should be labeled TILT as they start reacting not only to chemicals but molds as well.

Thousands of people have the same sensitivity and go through the same confusion of reacting to chemicals that are first invisible and only through investigations and time is it consistently found that reactions come before the cause is sensed. It is believed by many to be a chemically induced physiological disorder (physiological is a condition in which the organs in the body malfunction causing illness, examples are Asthma, Glaucoma, Diabetes). Some doctors have been taught that MCS is a mental condition. We believe that MCS is NOT a psychiatric caused disorder however it may be that the brain is the first organ affected and it is then making the person legitimately sick. Living with MCS can result in causing severe anxiety and putting the patient and/or family into a state of psychiatric distress.

In some people it is believed that a combination of markers in long term testing can sometimes show evidence in some (but not all) with this disease. TA1, H/S, Helper, Lymph’s and B-Cells and many others are shown below. MCS was originally hard to define as it encompasses a whole spectrum of sensitivity different between each patient. The syndrome can cause what seems to be excess fear to those unaffected but it understandable fear to those that understand the harm caused to the individual (and that person’s loved ones) by this condition. MCS is not a mental disorder, but MCS is a disease in which the body has extreme reactions to man-made chemicals.

Also, thorough ENT exam shows abnormalities in a high percentage of multiple chemical sensitive patients. They show:
Elevated levels of chemical antibodies in a symptomatic patient. A significant change in IgG (benzene ring) and IgM (isocyanate) levels decreased after exposure ceased and the patient became "asymptomatic" (while however still chemically sensitive). ANA titers were positive in 17% of 96 patients. The highest percentage of elevated antibodies was seen when anti-myelin antibodies were studied. They were positive in 80% of 50 patients studied. Typically, the elevation was in the IgM and/or IgA rather than IgG antibodies. In contrast to findings, "normals' have been reported to have a very low incidence of positive autoantibodies: ANA 3-4%, parietal approximately 2%, smooth muscle approximately 3%, mitochondrial approximately 1%. Other medical conditions caused by MCS include atrophic rhinitis in patients with severe nasal complaints. Sinusitis or at least thickened mucous membranes were found on sinus examination. Ta1 cell elevation. An increase in TA1 cell count and percentage is the most frequent abnormality in patients with MCS. Helper/suppressor (H/S) ratios can be increased (50%), unchanged, or decreased upon random testing. Suppressor cells decreased in 27% of 110 patients. Whether their continued decrease leads to auto-immune disease is not yet apparent from our initial data. Mitogenesis was abnormal in 42% of 12 patients. Normal ranges in our control group were as follows: TA1 Cells 0-432/mm3 or 0-10%; H/S ratio 1-2.2; Helper Cells 336-2,376/mm3 or 35-55%; Suppressor Cells 192-1598/mm3 or 20-37%; Lymphocytes 960-4,320/mm3 or 20-40%; B Cells 48-648/mm3 or 5 – 15%.  A significant decrease to normal levels of chemical antibodies in a patient who traveled out of state and stayed in a "non-contaminated" environment where she slowly became "asymptomatic". TA1 cells were not a good marker of MCS in this case. Ta1 is a 105,000 dalton protein that is weakly expressed on a small fraction of resting human peripheral blood T cells but strongly expressed in vitro on T cell clones and a substantial proportion of activated T cells. Unlike receptors for growth factors such as IL 2, the Ta1 antigen is present on T cell lines and clones irrespective of cell cycle. The function of Ta1 was investigated after separation of T lymphocytes into Ta1-enriched and Ta1-depleted subpopulations that were obtained from normal human subjects. Although Ta1-enriched T cells constitute only 10 to 15% of the E rosette-positive lymphocyte population, most, if not all, of the anamnestic response to the recall antigens tetanus toxoid and mumps reside in the Ta1+ population. Both Ta1-enriched and -depleted cells responded equally well to the mitogen PHA. The autologous mixed lymphocyte response was also greater in the Ta1-enriched subpopulation but not to the degree seen with soluble antigen. Increased proliferation was not due simply to increased inducer cell function within the Ta1+ subpopulations because both Ta1- and Ta1+ cells induced similar amounts of Ig synthesis in the presence of PWM. Additionally, increasing numbers of Ta1- cells did not suppress the enhanced proliferative responses of Ta1+ cells, and thus Ta1- cells do not appear to be functioning as suppressor cells. The Ta1 antigen appears to be a marker for previously activated T cells in peripheral blood, and this subpopulation appears to include T memory cells.

Cells of the immune system can be shown as abnormal and slowly approach normal as the patient stays away from a sick induced home for several months. Some patients get bedridden from exposure at home and are no longer bedridden after some amount of time after removing themselves from the environment that was causing them to be sick. A person with MCS or TILT is never healed but they can become significantly better in better environments. Unfortunately, with MCS and TILT a friend or spouse may go back and re-enter an abandoned "sick" home to fetch some belongings only to bring the mold or embedded chemicals back with them. The TILT person often must leave mold exposed belongings (such as cloth and wood items) that just can't easily (or sometimes can never) be sterilized. It is a real, chronic, and progressive disease that can only be treated by avoidance. Many can only find some health improvement by moving out of their homes. The reality is that finding a safe home can be extremely difficult. Most home have used pesticides, cleaners, paints, air fresheners and other chemicals residuals that can cause issues for an MCS person for years.

Certain individuals exhibit sensitivity to molds, and exposure to these fungi can result in symptoms such as a congested or stuffy nose, wheezing, and irritation of the eyes or skin. Those with pre-existing allergies to molds or asthma may experience more pronounced reactions. Workers exposed to significant amounts of molds in occupational settings, such as farmers dealing with moldy hay, may undergo severe reactions, including fever and difficulty breathing.

In 2004, the Institute of Medicine (IOM) established a connection between indoor mold exposure and upper respiratory tract symptoms, coughing, and wheezing in otherwise healthy individuals. Additionally, it linked mold exposure to asthma symptoms in individuals with asthma and hypersensitivity pneumonitis in those vulnerable to this immune-mediated condition.

We now know that even small amounts of chemicals can not only cause sickness but also a multitude of other issues in people. What appeared to be very small concentrations of perfumes, fumes, smoke, and mist can trigger headaches in some patients but not in friends and family members who were present in the same environment. This realization became a starting point for doctors and the increasing interest in understanding chemical sensitivity. A person with MCS gets sick to just the smallest amount of chemicals in their environment... often at levels that are otherwise undetectable to the human senses, proving that the sensitivity is real. A person will have real reactions before they are aware of the chemicals in their environment and for this reason, we know that MCS is a real reaction. How or why it only affects a small percentage is really unknown. How to chemically diagnose and prove a person has MCS (beyond their visible reactions) is also unknown.

So, what does the medical community in the world say. Countries that recognize MCS include Germany, followed by Denmark, Sweden, Austria, Luxemburg, Spain, Finland and Japan. MCS is classified in Germany and Austria under the ICD-10 code T78.4 (unspecified allergies, Nitrous Oxide System-hypersensitivity, NOS-idiosyncrasy). In Sweden, Electro-Magnetic Hypersensitivity, (EMH) is recognized as well. The Canadian Federal Centre for Occupational Health and Safety, as well as some local Canadian agencies, has recognized MCS and other related syndromes like SBS as pivotal health and safety issues but currently describe it as a disorder in the brain from unknown causes. In Italy, MCS is not yet nationally recognized by the Ministry of Health, but it is recognized locally by some regional authorities as a rare disease. Although the World Health Organization (WHO) has yet to assign clear separate code for MCS or related diseases within the International Classification of Diseases (ICD-10). Two existing generic codes, J68.A and T78.4 (which respectively refer to “unspecified respiratory condition due to inhalation of chemicals” and to “unspecified allergies”) might be applied to some MCS cases, although they do not specifically include MCS symptoms.

So why is MCS not treated as a disability in the USA. In our opinion the reason may be the same as to why they can't cure cancer or 1000 other diseases... we just don’t know how to chemically diagnose or treat MCS. The diagnoses is based on the patients recounting multiple symptoms and where all other medical testing shows no other disease. The treatment is avoidance and supplements and not medicines. This is currently not acceptable in the medical, pharmaceutical or disability community. With no way to definitely test yet the risk for abuse is great.

We no longer believe any study that says MCS is a psychiatric condition. This is the catch all to avoid insurance and govermental support. MCS is likely to be the brain is reacting physiologically with distress as bodies receptors bring thedamaging chemicals to the brain. Anxiety is a likely result of having MCS and not likely the cause for the sufferer. In our opinion it may take another 20 or 30 years before medicine has the answers to MCS. Although most of the world's medical community agree that they can attribute the symptoms of soldiers from the Gulf War they do not have a definitive way to diagnose it. Still, this is accepted because the sample group is large and similar, and they know they were most of all exposed to high levels of petroleum pollution and pesticides. Current medical practice says it is a mental anxiety disease. They would have applied this to the Gulf war vets too but why did the men from the Vietnam or Korean war not have this? The medical community is not yet equipped to handle MCS. Scientific studies prove that the agents that cause MCS are real. However, because it takes far more chemicals in the average person it is as of yet impossible to validate those with extreme sensitivities using current medical methods.

Most doctors have patients with some level of MCS but the medical community in the USA is still not taught anything about MCS or the dangers of many common chemicals in medical school. Another reason it may not be recognized in the USA is due to the extreme cost and burden that MCS recognition would cause to the disability system and chemical producers in the USA. Also, because no “medicine” is known that can treat MCS, and it is often those same big chemical corporations that made the poison we feel makes people sick.  When disability coverage was allowed in the USA, the multiple chemical sensitivity patient was given "other" specific names ie Gulf War Syndrome and only to the worst provable and usually military causes. So, in the USA we find that MCS is usually only covered when it comes with a known, and proven, government cause and liability, so as to limit the USA social security/disability liability.  In the United States, MCS has also been partially recognized by several medical authorities. For example, the Centers for Disease Control and Prevention (CDC) established the presence of chemical intolerances in patients affected by CFS and Myalgic Encephalomyelitis (ME). Federal agencies such as the Environmental Protection Agency (EPA), the Department of Housing and Urban Development (HUD), and the Social Security Administration (SAA), as well as legislation such the American with Disabilities Act (ADA), have paid at least some attention to MCS. Thousands of people in the USA have now been listed as having MCS and many hav lost their homes, family and careers with no financial help because of it.

In 2009, the World Health Organization (WHO) issued supplementary guidance titled the WHO Guidelines for Indoor Air Quality: Dampness and Mould [PDF – 2.65 MB] {Summary} [PDF – 167 KB]. Recent studies have proposed a potential association between early mold exposure and the development of asthma in certain genetically susceptible children. Moreover, interventions that enhance housing conditions have been suggested to reduce morbidity from asthma and respiratory allergies.

Mold sensitivity often goes along with MCS. While a link between molds, including Stachybotrys chartarum, and various adverse health effects like acute idiopathic pulmonary hemorrhage in infants, memory loss, or lethargy has not been conclusively proven, further studies are necessary to understand the causes of acute idiopathic hemorrhage and other adverse health effects. It's important to note that there also is no specific blood test for mold exposure. While some physicians can conduct allergy testing for potential mold allergies, there are no clinically proven tests to precisely identify when or where a specific mold exposure occurred.

So is MCS an AUTOIMMUNE Disease? Researchers have studied immunity biomarkers in people with MCS and so far the results have been compelling but inconclusive like so much of the research into MCS.

Here are some examples we found of people getting tests that showed that there can be some identifiers to this disease. There have been scientific markers documented with the spouses or associates of the afflicted. One married couple showed rapid increase in TA1 cells and decrease in immunocompetent natural killer cells (NKHT3). An increase in IgM antibodies to TMA, phthalic a-hydride and compounds with a benzene ring, and also in IgG antibodies to the benzene ring, approximately two weeks after significant exposure. By contrast changes in TA1 cells were seen within only one day!  A student with MCS who entered an anatomy laboratory for sufficient length of time to become severely symptomatic. By contrast, T-cells and helper-suppressor ratios did not change within that same time interval. Antibodies to TMA can be the only antibodies elevated after exposure. So a patient should serve as his/her own control and therefore all studies should be longitudinal. Results show that properly timed studies can bring about significant changes in certain parameters after self-reported exposure. We are not certain at this time when TA1 cell counts reach a peak after exposure. We now know however, that these cells are elevated one to two days after exposure. We are also uncertain when chemical antibody levels reach a peak value. All we have shown so far is an elevation about two weeks after exposure. Chemical exposure and its effects on the immune system has recently become the subject of discussion by leading allergists. Changes in immune cell populations, specifically TA1 cells, alter exposure to chemicals were recently proven by another group. Chemical antibody measurements in chemically exposed patients recently became commercially available. Appropriate immunological procedures were originally developed by Dr. Wojdani and used in patients of the senior author (Thrasher et al., 1987). The original procedures were then expanded by Dr. Wojdani to include additional chemicals (this paper) and adopted and verified by another laboratory (Antibody Assay Laboratories) where additional research was done and published (Thrasher et al., 1989; Thrasher et al., 1990). At this time, it should be noted that benzene is not per se antigenic. However, our data suggests that some chemical compounds containing the benzene ring are antigenic. Further studies are needed to determine which of these compounds cause antibody formation. Data suggests that chemical exposure can even push some patients in the direction of autoimmune disease. Multiple sclerosis is an example. Several of our patients are suspected of having that disease based on not only their clinical presentation but also abnormal MRI and evoked response studies together with high anti-myelin antibodies. This was previously discussed (Gard and Heuser, 1990). Studies other than immune tests should also be done in a longitudinal fashion. Cost containment, a lack of research funding and other factors made this impossible in our patient population. However, PFT was at times studied immediately after exposure and became abnormal. It is possible that some neurological parameters (EEG, BEAM, and SPECT) may also show some significant changes. While we have come to expect a high percentage of abnormal immune function tests, we were surprised at the high percentage of abnormal neurological tests. This shows that the "psychiatric" presentation by many of these patients actualy had a neurological basis. The high number of abnormal test results in our patient population is probably explained by the fact that many patients were disabled with MCS and therefore quite sick. EEG and SPECT studies point toward the limbic system as being involved in MCS. This system's possible role is aptly discussed in this conference by Dr. Miller. It, together with the role of the olfactory system deserves further study (also see Dr. Bell's presentation at this conference). Early studies by Russian authors (Bokina et al., 1976) pointed in this same direction. EEG studies showed mostly mild abnormalities in the temporal and adjacent leads, our youngest patients (sister and brother, ages two and four respectively) developed actual clinical seizures with grossly abnormal EEGs about three weeks after moving into a new home and playing on the brand-new carpet. For several months thereafter the mother observed MCS in both her children. Seizures and MCS slowly abated after the family moved out of the new home.

The diagnosis of MCS should be suspected if a patient reports impaired well-being whenever exposed to more than one chemical in concentrations which do not affect the general population. In the extreme, the concentrations are very low, and the patient is very sick and claims disability. A comprehensive evaluation of seven systems should then be undertaken. Not all seven systems (central nervous system, peripheral nervous system, nose and sinuses, PFT, T-cells subsets, chemical antibodies, autoimmune panel) are always affected. However, we suggest that abnormalities in four out of these seven systems strengthen the suspicion of MCS. If parameters become abnormal or become more abnormal following self-reported acute exposure, the diagnosis is basically confirmed. Studies in environmentally controlled chambers will be necessary to further advance the field. Physical testing diagnostic criteria for MCS is not yet standardized and not all that suffer will show positive test results in current diagnostics. In fact, someone with TILT (MCS plus mold or other triggers) may not show abnormalities in any of the seven above tests while they may be sicker and more reactive to those that did test positive in some or all of the above. It is because of this that MCS can be difficult to prove to someone other than the victim. Until standardization is possible the best test is the comprehensive question test found at the TILT research lab. https://tiltresearch.org/qeesi-2/

A movie called "SAFE" (not recommended), released in 1995, showed how MCS sickness develops and highlights the misunderstandings of the day with doctors not trained or knowledgeable however it ends up siding with the doctors of the day in that it can’t be chemicals... It is just a drama story written and directed by Todd Haynes and starred Julianne Moore that stood with the doctors of the day in theorizing MCS must be caused by something other than chemicals. It was incohesive in that all these people affected with clear, individual, unexpected, and similar physical MCS symptoms, directly connected to the same  man-made chemicals but then it brings in the thought that the disease is all in their minds needing a commune while contradicting itself as that positive thinking did not bring the healing while the avoidance helped.

Some conclusions

MCS is real, progressive, and disabling. Patients who present with complaints of MCS deserve a comprehensive objective evaluation. If a patient shows the same causes and symptoms listed in this, and all other tests cannot show other causes, then the environment around you needs to change for you to experience some healing. If actual blood and chemical tests are performed a percentage will come back with abnormal test results but know that many afflicted with TILT or MCS may not show any abnormalities in the tests listed above but they still have MCS and/or TILT. For this reason, the questionnaire tests should be the basis for the patient and the physical tests used to help the find/determine and avoid causes. This is true if the central and peripheral nervous systems as well as pulmonary and immune functions are tested. Often anatomical changes are found in the nasal passages on close inspection. By contrast, CBC and blood chemistry are usually within normal limits. So are findings on general physical examination. Whenever possible, longitudinal studies should be performed in which the patient is used as his/her own control. Increases in TA1 cells and chemical antibodies can then be seen following self-reported unintentional exposure and are therefore suggested as markers of MCS.

There are different diagnostic criteria for MCS at different clinics, but some standardization is desired. These are sorely needed as the number of patients who claim disability because MCS is growing in the world outside the USA. Billions of dollars are potentially at stake as claims increase. Patients who are truly sick deserve attention and help from industry, housing authorities and government agencies as well as physicians. The biggest problem for the system is that patients who make unjustified claims cannot be identified. Patients and industry and government are all in need of a practical approach to the diagnosis of MCS. 

WHAT ACTUALLY CAUSES CHEMICAL SENSITIVITY? People can become sensitive to chemicals after a major chemical exposure or after long-term, low-level exposure to chemicals, pesticides. Chemical sensitivity can also occur after a virus or other illness, or with hormonal disturbances, during or after pregnancy. A percentage of the population can get MCS from even a small dose of any number of potential chemicals because they are intolerant of it. Once MCS starts it will progress into other chemicals and symptoms.

The study of the effects of the environment upon the individual is now feasible due to new technology developed in the construction of environmental units.1,2,3. Our observations reveal that individual or multiple organs may be involved. The brain is the target organ in only a subset of chemically sensitive patients, and its involvement should not be confused with psychosomatic disease.

Over a 16-year period physicians and scientists at the Environmental Health Center in Dallas had an opportunity to observe over 20,000 patients who had chemical sensitivity problems. These patients were studied under various degrees of environmental control. This experience is unique in the world and has resulted in numerous peer-reviewed scientific articles, chapters in books, and books on this subject. Studies have resulted in over 32,000 challenge tests by inhalation, oral, or injection methods, of which 16,000 are double-blind. Blood chemical levels and fat biopsies for organic hydrocarbons number over 2,000, while the measurement of immune parameters are over 5,000 tests. Objective brain function tests have been accomplished in over 5,000 patients. Other objective tests, like computerized balance studies, depolluting enzyme levels, and autonomic nervous system changes as measured by the Iriscorder, number near 1,000.

We wish to share our findings with the participants of the National Academy of Sciences Committee for the study of chemical sensitivity.

Chemical sensitivity is defined as an adverse reaction to ambient doses of toxic chemicals in our air, food, and water at levels which are generally accepted as subtoxic. Manifestation of adverse reactions depend on: (1) the tissue or organ involved; (2) the chemical and pharmacologic nature of the toxin; (3) the individual susceptibility of the exposed person (genetic make-up, nutritional state, and total load at the time of exposure); (4) the length of time of the exposure; (5) mount and variety of other body stressors (total load) and synergism at the time of reaction. (6) the derangement of metabolism that may occur from the initial insults.

To demonstrate cause-and-effect proof of environmental influence on an individual's health, one must understand several important principles and facts. These principles involve those of total body load (burden), adaptation (masking, acute toxicological tolerance), bipolarity, biochemical individuality. Each principle will be discussed separately.

This is the patient's total pollutant load of whatever source (usually from air, food and water or surroundings1,2,4. The body must cope with this total burden; usually it must be utilized, expelled or compartmentalized. Total body load includes: (1) physical factors (e.g. hot, cold, weather changes, positive ions.5 electromagnetic phenomena.6 radon); (2) toxic chemicals (e.g. inorganics: Pb, Cd, Hg, A1, Br, etc.; organics: pesticides, formaldehydes, phenols, car exhausts, etc.).7-21 (3) biological (bacteria, virus, parasites, molds,22 food.)23,24 (4) psychological or emotional factors also significantly affect the patient, confirmed by recent work in psychoneuroimmunology, linking the psyche and the neuroendocrine and immune systems.25,26,27,28 Failure to reduce the total body load prior to pollutant challenge will frequently yield inaccurate results. Accordingly, we believe it is essential to conduct investigative procedures in controlled environmental circumstances with the total load reduced.

Adaptation (Masking, Acute Toxicological Tolerance)

Induced by the internal or external environment, this is a change in the homeostasis (steady state), of body function with adjustment to a new "set point."29,30,31,32 Adaptation is an acute survival mechanism in which the individual "gets used to" a constant toxic exposure to survive, at the same time suffering a long-term decrease in efficient functioning and perhaps longevity. Selye was among the first to describe this compensatory mechanism.33 Because of adaptation or tolerance, the patient's total body load may increase undetected because the perception of a cause-and-effect relationship is lost. With no apparent correlated symptoms, repeated exposures may continue to damage his immune and enzyme detoxification systems. 34,35 The eventual result of continued toxic exposure over a period of days, weeks, months to years is end-organ failure.21 Withdrawal or avoidance of an offending substance for at least four days will aid in reducing the total body load, after which a controlled re-exposure challenge will reproduce cause-and-effect reactions. In these deadapted individuals, there is high reproducibility of these evoked reactions permitting the physician to acquire sound scientific information.


After an exposure, the body initially develops a bipolar response of a stimulatory phase followed by a depressive phase,37,29,1 usually with induction of immune and enzyme detoxification systems.38 If the incitant is strong enough, or if substantial size or duration of exposure occurs, the induced enzyme and immune detoxification systems are depleted or depressed by overstimulation and overutilization. An individual may also initially experience a stimulatory reaction in the brain, perceiving the inciting substance not as being but as actually producing an energizing "high". Therefore, he continues to acquire more exposures. After a period of time, however, be it minutes, months, or years, his body's defenses are adversely overstimulated and he develops disabling depression-exhaustion symptoms.31 This stimulation and depression-exhaustion pattern has been observed with many pollutant exposures, including ozone.30,12 When studying the effects of pollutants upon adapted individuals, the stimulatory phase is often missed or misinterpreted as being normal, thus giving faulty data. Studies in the controlled environment, involving 16,000 challenges in 2,000 deadapted patients, have proven this bipolarity phenomenon repeatedly.

Biochemical Individuality

Another principle necessary to understand environmental aspects of health and disease, and especially chemical sensitivity, is that of biochemical individuality. Biochemical individuality of response is the individual's uniqueness. This uniqueness of response depends on the differing quantities of carbohydrates, fats, proteins, enzymes, vitamins, minerals, immune and enzyme detoxification parameters with which an individual is equipped to handle pollutant insults. These variations determine an individual's ability to process the noxious substances he encounters. They further contribute to the intensity of his reaction to toxic exposures and to his susceptibility to chemical sensitivity. Thus, a group of individuals may be exposed to the same pollutant. One person may develop arthritis, one sinusitis, one diarrhea, one cystitis, one asthma, and one may remain apparently unaffected.

We have differing quantities and interactions of carbohydrates, fats, proteins, enzymes, vitamins, minerals, and immune parameters with which to respond to environmental factors. One simple example is the noted relationship between low serum magnesium levels and the HLA B35 genotype. This biochemical individuality allows us to either clear the body of noxious substances, or to collect them and contribute to the body burden. Biochemical individuality is dependent on at least three factors: genetic endowment, the state of the fetus's nutritional health and toxic body burden during pregnancy, and the individual's present toxic body burden and nutritional state at the time of exposure.

Some individuals, for example, are born with significantly lower quantities of specific enzymes (it may be 75%, 50% or even 25% of the norms). Their response to environmental stimuli is often considerably weaker than those born with 100% of the normal detoxifying enzymes and immune parameters. Examples are the babies with phenylketonuria or the individuals with transferase deficiency, who do well until exposed to their environmental triggers, and then damage sets in. There are over 2,000 genetically transmitted metabolic errors, suggesting that most of the population will have at least one abnormality.41 Toxic volatile organic chemicals have been shown by Laseter to bioconcentrate in the fetus, increasing the acquired burden in some babies.

It is well known that some individuals acquire their toxic load at work or around their homes. This changes with different seasons and weather conditions thus giving variable effects and responses over time. Extreme care must be taken in evaluation of each patient, who may exhibit unique clinical responses due to his specific biochemical individuality. As an example, it is well known that not all patients will exhibit every reported symptom associated with systemic lupus erythematosus (SLE). Similarly, each patient exposed to the same environmental pollutant will react with his or her unique complex of symptoms. Because this vital fact is misunderstood, many studies are flawed when the wrong signs and symptoms are assessed for that individual.

Spreading Phenomena

Spreading is a secondary response to pollutants that can involve new incitants or new target organs. Spreading that involves new incitants occurs when the body has developed increased sensitivity to increasing numbers of biological inhalants, toxic chemicals, and foods at increasingly smaller doses. At this time, overload becomes so taxing that a minute toxic exposure of any substance may be sufficient to trigger a response or autonomous triggering my occur. For example, a person initially may be damaged by a pesticide and then eventually have his disease process triggered by exposure to a myriad of toxic chemicals and foods, such as phenol, formaldehyde, perfume, beef, lettuce, etc. Spreading may occur for many reasons. It may be due to a failure of the detoxification mechanisms—oxidation, reduction, degradation and conjugation—brought about by toxic overloading, or it may occur because of depletion of the enzyme or co-enzyme's nutrient fuels, such as zinc, magnesium, all B vitamins, amino acid, or fatty acid. This depletion may account for an increasing inability to detoxify and respond appropriately. The blood brain barrier or peripheral cellular membranes of the skin, lung, nasal mucosa, gastrointestinal or genitourinary systems may be damaged allowing previously excluded toxic and nontoxic substances to penetrate to areas that increase the risk of harm. Immune or pharmacological releasing mechanisms may become so damaged that they are triggered by many substances toxic, then non-toxic (such as food) in addition to the specific one to which they were intended to respond. It is well substantiated that antigen recognition sites may be disturbed or destroyed by pollutant overload. Hormone deregulation (feedback mechanisms) may occur allowing for still greater sensitivity.

In contrast to patients who experience increased sensitivity to multiple triggering agents, some chemically sensitive patients may have one isolated organ involved in their disease process for years, only to have dysfunction spread to other organs as their resistance mechanisms break down. This kind of spreading from one to another or multiple end-organs enables the progression of hypersensitivity and the eventual onset of fixed named disease.

Switch Phenomenon

The switch phenomenon is the changing of one end-organ response to another. This usually occurs acutely but may occur over a much longer period of time. This phenomenon was first described by Savage in the 1700s. He observed that when mental patients were at their worst, they usually had a remission of their asthma or sinusitis. When they were better mentally and they were seen in the outpatient clinic, they had a much higher incidence of sinus and asthma problems. Randolph and most other environmentally oriented physicians have also observed this phenomenon. At the EHC-Dallas, we have observed similar occurrences in our patients and, in fact, take cognizance of this phenomenon when evaluating therapy outcome.

In observing thousands of controlled challenges in the environmental unit, we have seen the target organ responses of many of our patients switch to several different ones during a long (e.g., 24-hour) reaction. Often, we have seen, for example, transient brain dysfunction followed by arthralgia, followed by diarrhea, followed by arrhythmia.

Therapy can appear to have been effective, even when a pollutant has not been eliminated. In this case, a new set of symptoms may begin indicating that a pollutant response has simply switched to another end-organ. This phenomenon occurs frequently when symptom-suppressing medication therapy or inadequate environmental manipulation is used. For example, a patient may have his sinusitis cleared by medication (e.g., cortisone). but later, since the cause has not been eliminated, he may develop arthralgia and eventually arthritis, or his colitis may have cleared only later to have cystitis develop.

This life-long progression of disease does not have to occur if the switch phenomenon is recognized during initial evaluation. To prevent it, individuals and physicians need simply to be cognizant of seemingly unrelated events. For example, statements are often made to the effect that a child will outgrow a problem when one symptom complex dissipates only to be replaced by a new set of symptoms. For example, a child may have recurrent ear infections. Eventually, these may stop, but bedwetting may ensue. Over time the bedwetting may cease, but the child may then develop asthma. These changes in health may appear to be totally unrelated; in this instance, however, they are switch phenomena. The situation of an adult who sprays pesticides in his home, and then visits a neurologist with complaints of headaches and a rheumatologist with symptoms of arthritis is similar. Both the physician and the patient frequently fail to recognize the relevancy of these seemingly disparate symptoms as being part of a larger pattern needing further investigation.

Pollution Facts

In order to accomplish concise studies of the chemical sensitivity phenomena, one must understand some facts about environmental pollutants.

Modern technology's rapidly accelerating rate of growth has produced a wide variety of chemical products, that contribute to the total chemical environment. Recent studies show that nearly 50% of the global atmospheric pollutants are generated by man, (either isolated from natural products or synthesized), and the ubiquitous nature of the toxic chemical agents is widely appreciated. It has been estimated that more than 2,000 new chemical compounds are introduced annually, and that over 60,000 different organic chemicals are used commercially today.

The widespread presence of hazardous chemicals has rendered critical the environmental sensitivity problems described by Randolph almost 40 years ago.43 While celebrated instances of gross contamination have long been the object of professional attention, only recently have literally thousands of synthetic chemical products, heretofore believed innocuous, been incriminated as agents of homeostatic dysfunction.

Current data affirm the view that standard methods for the determination of chemical incitants may no longer be effective. With the finding that sensitivities can occur from subthreshold and picomolar quantifies of chemicals, has come the discovery that standard procedures, such as skin prick or scratch tests, often fail to demonstrate positive reactions which are otherwise verifiable.

Recent literature confirms the harmful effects of chemical incitants, like formaldehyde, phenol, some pesticides, chlorine, and petroleum alcohol. Commonly encountered chemicals like glycine, DDT, toluene and turpentine and drugs such as hydralazine have been found to induce advanced-staged disease process.

Several familiar metals have also been incriminated, among them nickel, cobalt, chromium, aluminum, mercury, and platinum. Other common environmental chemical incitants include xylene, various acrylates, and acrylated prepolymers, benzyl peroxide, carbon tetrachloride, sulfates, dithiocarbamates, and diisocyanates. 

Water Pollution

Water has an important role in delivering contaminant minerals, toxic organic and inorganic chemicals, particulate matter and radiation to the human organism. In developed nations, the incidence of many chronic diseases, particularly cardiovascular disease, is associated with water characteristics, like purity and mineral content. Hardness, or the lack thereof, is involved in heart disease, hypertension, and stroke. Among the theorized protective agents found in hard water are calcium, magnesium, vanadium, lithium, chromium and manganese. Certainly, once cardiovascular pathology is induced, waters with high sodium content may be harmful. Other adverse agents include the metals cadmium, lead, copper, and zinc, which tend to be found in higher concentrations in soft water. Nitrates in water (usually from fertilizer) pose immediate threats to children under three months of age due to production of methemoglobin, and sulfur can also cause reactions in susceptible patients.

City water, much of it secondhand, often contains from 100 to 10,000 times as many synthetic compounds as natural spring water. This, coupled with the rapid growth in the use of synthetic chemicals, has focused concern on the chemical quality of drinking water. Although microbes are important, attention is now being drawn to the microchemical contaminants. Advances in analytic chemistry has been able to reveal chemical contaminants in the parts-per-billion or parts-per-trillion range. It is a serious mistake to assume that extensive contamination of drinking water with "low" levels of synthetic pollutants is "normal." These chemicals are widespread, and we should not be lulled into assuming these contaminants are innocuous. Examination of our ground water has revealed many hundreds of toxic chemicals in these ranges. 

Many examples of water contamination exist and have been documented, including Times Beach, Missouri with winter floods flushing dioxin-contaminated oil used 20 years ago, Niagara's Love Canal area, Waterbury, Connecticut, and Middleboro, Kentucky.

In many cases, deadly materials have been accumulating for years in dumps and landfills. In the United States, some 80,000 pits and toxic waste lagoons hold chemicals ranging from carbon tetrachloride to discarded mustard-gas bombs.68 Slowly escaping from their burial sites, these leftovers directly contaminate our ground water. Polluted ground water exists at 347 of the nations 418 worst chemical dumps, and probably is occurring in the rest. Laseter and others have shown that a virtual organic chemistry laboratory exists in most drinking water. 

In the early 1980s, California, New York, New Jersey, Arizona, Nova Scotia, and Pennsylvania condemned dozens of public water supply wells due to trichloroethylene or tetrachloroethylene pollution. Leaking fuel tanks contaminated nine Kansas public water supplies in 1981.Officials in New Mexico identified 25 cities where hydrocarbons and solvents contaminated the ground water. Analysis of New Orleans drinking water alone revealed the presence of 13 halogenated hydrocarbons.

Sources of water pollution fall into three major categories: (i) municipal sewage; (2) agricultural wastes; and (3) industrial wastes. Approximately 55% of the water treated in municipal plants is from homes, while another 45% is from industry.

Agricultural wastes include those from livestock and toxic chemicals (pesticides, herbicides, fertilizers), and farm runoff collects in rivers, lakes, and ground water. Industrial wastes, however, contain some of our more toxic substances. Over one-half of the total volume of industrial wastes come from paper mills, organic chemical manufacturing plants, petroleum companies, and steel manufacturing. The major pollutants are chemical byproducts, oil, grease, radioactive waste and heat. Other sources of contamination are drinking water disinfectants and byproducts; 68 it should be remembered that chlorine, interacting with organic material, produces toxic trihalomethanes and other organochlorines. Alternatives to treating water with chlorine include ozone, chloramines, ultra-violet irradiation, iodination, or home reverse-osmosis and charcoal filtration.

Chloride, added at many sewage treatment plants, can also react with organic matter in the water to form chlorinated hydrocarbons, many of which are also known to cause cancer. Copper sulfate, aluminum sulfate and fluorine are other major contaminants which may add to the total body burden.

Over a thousand different toxic chemicals have been found in public water supplies including pesticides, herbicides, industrial solvents, and polychlorinated biphenyls, just to name a few.

Inorganic pollutants include arsenic, cadmium, chromium, copper, manganese, mercury, silver, and selenium. The use of inorganic arsenic insecticides has lead to high arsenic levels ha some water supplies. Barium (greater than 1 mg/L) has toxic effects on the heart, blood vessels, and nerves, while cadmium at levels greater than .Olmg/L has adverse arterial effects. At levels greater than lmg/L or one ppm, the following metals found as water contaminants have produced severe chronic toxicity: antimony, beryllium, cobalt, gold, iodine, lithium, mercury, and vanadium. In Minamata, Japan, between 1953 and 1960, various plastic companies dumped methyl mercury chloride into the water, producing 50 to 85 ppm of mercury ha nearby fish. Four hundred and six people died after ingesting these mercury-contaminated fish, and the adverse toxicological effects on developing children are continuing to be measured.

A recently completed study found that skin absorption contributed from 29 to 91% of the total body dose of pollutants (from water), with an average of about 64%. This is even more important when one looks at the large number of volatile organic compounds found in our drinking and bath water.

Radiation occurs in some waters in the form of radon, a naturally occurring radionuclide that seeps from rocks and may be concentrated in airtight homes, especially the basements. At this stage, more information is needed to fully assess its effects. It probably, however, can increase the total body load.

In 1965, a serious drinking-water problem was seen in 40 percent of patients hospitalized for a program of comprehensive environmental control. Today it is up to 80%. We have found that patients susceptible to water contaminants virtually always exhibit multiple sensitivities, with advanced and severe environmental reactions, especially to airborne chemicals.1 Interestingly, water sensitivity in children was found to increase on a circadian and seasonal basis. Increased severity was seen during June and July or in September and October, when grass, pollen, and mold counts were also high. Some ECU patients had difficulty with waters containing high levels of sodium, others with calcium, and still others with high bicarbonate waters. A few individuals tolerated distilled water, even though it may contain some hydrocarbon residuals. Hundreds of outpatients have shown symptoms in reaction to both chlorinated and non-chlorinated waters, including numerous spring, charcoal-filtered, and distilled waters. If these water-induced symptoms remain undiscovered, food and chemical testing may be distorted. It is vital to test and find safe water before proceeding with other testing in these severely sensitive individuals.

Chemical Contamination in Foods

The contamination of our urban food supplies is the result of widespread use of food additives, preservatives, and dyes in growth, manufacturing, and processing. Virtually all commercially grown and prepared foods have pesticides and herbicides in them.

The literature abounds with reports of chemical sensitivities to many additives. Contaminant reactions complicate the study of food sensitivity, forcing one to define more dearly the nature of the incitant, not only as it is encountered in foods, but in the air and water as well. Bell has reported urticarial reactions and immunological changes to exposures to a number of food additives. Condemi and Bell both suggest that food dyes may trigger reactions in sensitive individuals; including conditions commonly thought to be psychogenic, or certain forms of hyperreactivity. Lindemayer has associated urticarial reactions with several additives such as p-hydroxybenzoic acid propylester, benzoic acid, sodium benzoate, ponceau rouge, and indigo carmine. Monroe's data indicate a casual role played by tartrazine azo dyes and salicylates in the provocation of vascular alterations. Other additives, including sodium nitrite and sodium glutamate, have been found to trigger migraine phenomena in susceptible patients.

Sulfur dioxide and sodium salicylate can provoke asthmatic reactions, while aspirin-like food contaminants and dyes may trigger urticaria, angioedema, bronchoconstriction and purpura. An even wider variety of symptoms, including severe gastrointestinal disorders, has been associated with sensitivities to aniline, commonly found in rapeseed oil.

In our experience, natural toxic components of foods, such as alkaloids, phenols lectins, etc. must also be accounted for when studying the secondary food sensitivity which occurs from pollutant overload in the chemically sensitive. Therefore, three factors must be considered when evaluating the total food load. These are man-made pollutant contamination, natural toxic effects of foods, and food sensitivity. Failure to consider all three in the chemically sensitive patient may color or negate otherwise a dearly defined case of chemical sensitivity.

Chemical Incitants in the Home Environment

Indoor air pollution in the home environment has produced a multitude of sensitivities to chemicals. Time and space limitations allow only a cursory review of the numerous commercial hygienic products which can be noxious for chemically susceptible individuals. Among these are a wide variety of cosmetics, particularly those containing glycerin, propylene glycol, or butylene glycol, perfumes, and hair products such as dyes, creams, sprays, and shampoo. Moreover, sensitivities have been demonstrated to occur in association with lip salve, fingernail preparations, soaps, sanitary napkins, mouthwash, antiperspirants, contact lenses, contact lens solutions, and suntan lotions.

Reports are widespread of sensitivities to chemicals in textiles, including synthetic acrylic fibers, polyester spin finishes, epoxy resins, and synthetic clothing. Products such as fabric spray starch may also be considered toxic for the chemically sensitive individual for whom even the metallic buttons on blue jeans may trigger reactions to nickel. Formaldehyde on synthetics or tetrachloroethylene, from dry-cleaned clothing can also produce problems.

Household cleaning products, particularly those containing formaldehyde, phenols and chlorine are hazardous for many patients. Several laundry products and detergents may be identified as household incitants, as well as a number of products used to dean and polish furniture.

The very construction of many homes may prove dangerous for the chemically sensitive patient. Data suggests that chemicals contained in wood preservatives (e.g., pentachlorophenols) are environmental incitants capable of triggering a variety of symptoms. Others report problems with reactions to formaldehyde-containing pressboard, carpets, plywood, and petrochemical contaminants.

Current data confirm earlier findings regarding the hazards of pesticides such as DNP and fungicides. Moreover, research increasingly suggests the possibility of sensitivities to apparently innocuous items such as rubber bands, coins, epoxy and countless paper products. Pesticides, along with oil, gas or coal are major offenders for sensitive individuals.

Research shows house plants and common insects can now be viewed as environmental incitants or causes of homeostatic dysfunction. In addition, sensitivities to cold and heat, and to contaminants in household water supplies have been associated with symptoms ranging from urticaria to severe respiratory distress.

Natural gas heat and stoves, and routine insecticide or termite proofing of homes can be prime offenders in chemical sensitivity. One must consider these potential sources of contaminants when developing studies on chemical sensitivity. In our experience, failure to evaluate building and home environments before challenge testing will often make challenge studies invalid for the diagnosis of chemical sensitivity.


The mechanisms involved in chemical sensitivity are becoming clearer, one of which has pollutant injury occurring to the lungs or liver, with resultant free radical generation. Disturbances then occurs at the cellular, subcellular and molecular levels, producing injury either immunologically, or nonimmunologically through enzyme detoxification systems. Vascular or autonomic nervous system dysfunction will then occur with one or a myriad of end-organ responses.


Type I hypersensitivity is usually mediated through the IgE mechanism on the vessel wall. Classic examples are angioedema urticaria, and anaphylaxis due to sensitivity to pollen, dust, mold, or food or some chemicals such as toluene diisocyanate. Ten percent of the patients with immunological involvement with chemical sensitivity seen at the ECH-Dallas seem to fall within this category.

Type II cytotoxic damages may occur with direct injury to the cell. A clinical example of this is seen in patients exposed to mercury. A group in Minimata, Japan developed neurological disease from eating fish exposed to toxic methyl mercury chloride. Mercurial pesticides fall into this category. Twenty percent of the patients with immunological involvement seen at the EHC-Dallas seem to fall into this Type H category.

Type III shows immune complexes of complement and gamma globulin damaging the vessel wall. A clinical example of this is lupus vasculitis. Numerous chemicals, including procainamide and chlorothaizide, are known to trigger the autoantibody reaction of lupus-like reactions. Many other toxic chemicals can also trigger the autoimmune response. Other chemicals, such as vinyl chloride, will produce microaneurysms of small digital arterioles, probably due to this mechanism.

Type IV (cell-mediated) immunity occurs with triggering of the T-lymphocyte. Numerous chemicals such as phenol, pesticides, organohalides, and some metals will also alter immune responses, triggering lymphokines, and producing the Type IV reaction. Clinical examples are polyarteritis nodosa, hypersensitivity angiitis, Henoch-Schonlein purpura, and Wegener's granulomatosis. A recent study done at the Environmental Health Center-Dallas on proven chemically-sensitive individuals (vascular, asthmatic, and rheumatoid), comparing them with normal controls, showed that those manifesting a chemical sensitivity through their vascular tree had suppression of the suppressor T-cells (greater than 4 S.D.). Clearly the larger portion of our patients with immunological involvement fall into the Type III and IV categories.

Non-Immune Enzyme Detoxification

Non-immune triggering of the cell and vessel wall may occur. Complement may be triggered directly by molds, foods, or toxic chemicals, and mediators like kinins, postaglandins, etc. may also be directly triggered. These reactions then cause vascular spasm, with resultant hypoxia and release of lysozymes, which further produces more spasm, hypoxia, etc. Eventually organ failure will occur. Triggering of the enzyme detoxification, mostly in the systems liver and respiratory mucosa, plays an important role in clearing of pollutants. It occurs, however, to a lesser extent in all systems. Foreign compound biotransformations have considerable variability, depending on genetic factors, age, sex, nutrition, health status, and the size of the dose.

The metabolism of foreign compounds usually occurs in the microsomal fraction (smooth endoplasmic reticulum) of liver cells. A few biotransformations are non-microsomal (redox reactions involving alcohols, aldehydes and ketones). There are basically four biotransformation categories — oxidation, reduction, degradation, and conjugation.

The first three biotransformation pathways for xenobiotics are the same pathways that the body uses to process food and nutrients. If these enzyme systems are over-utilized by competing foreign pollutants, inadequate handling of food proteins can result, with the subsequent induction of food sensitivities. However, because these detoxification pathways are dependent on nutrient and mineral cofactors, these systems are inducible by appropriate oral or systemic supplementation. Such supplementation serves as an important factor in stabilizing and treating patients with chemical sensitivity. The fourth category of biotransformation, that of conjugation, is almost exclusively for handling foreign compounds. Conjugation appears to be uniquely utilized for the catabolism of foreign compounds, using amino acids and their derivatives with peptide bonds, and carbohydrates and their derivatives with glucide bonds. Simpler compounds like sulfate and acetate are also involved in conjugation with linkage of ester bonds. Activated conjugated compounds plus specific enzymes are often detoxified by coupling with co-enzymes, Examples: co-enzyme A with acetate, and other short-chain fatty adds adenosine or phosphoadenosine phosphate is detoxified with a methyl group from sulfate methionine, or the ethyl group from ethionine. Similarly, uridine and phosphate with glucose and glucuronic acids.

There are generally five major categories of foreign-compound conjugative processes. These are: 1) acetylation through co-enzyme A, for detoxifying aromatic amines and sulfur amides; 2) peptide conjugation with glycine and aromatic carboxylic acids to hippuric acid; 3) sulfonation with glutathione (containing cysteine) or PAPS, and microsomal enzyme conjugation for multi-ring systems such as naphthalene, anthracene, and pheno-anthracene, which eventually results in benign mercaptic acids or alternatively benign sulfate esters; 4) alkylations by methionine of amines, phenols, thiols, noradrenalin, histamine, serotonin, pyridine, pyrogallol, ethylmucaptin sulfites, selenites and tellurites; 5) Glucuronation. Glucuronides detoxify pesticides, alcohols, phenols, enols, carboxylic acid, amino hydroxamines, carbamides, sulfonamide and thiol. All of these processes are dependent upon nutrient fuels to keep these processes running efficiently. Toxic chemicals disturb the supply of the nutrient fuels by 1) producing poor quality food, 2) reducing intake, 3) reducing normal absorption, 4) setting up competitive absorption in the gut with nutrients, 5) imbalancing intestinal flora, 6) disturbing transport mechanisms, 7) disturbing proper decomposition and metabolism, 8) causing renal leaks, and 9) directly damaging nutrients. If nutrient inadequacy occurs, normal metabolism is overloaded and disturbed, resulting in selective changes in the pools of nutrients such as vitamins, minerals, amino adds, enzymes, lipids, and carbohydrates. Once this occurs, there is a viscous cycle of dysmetabolism, often with production or worsening of chemical sensitivity. These detoxification and metabolic defects are often measurable and have been accomplished in over 2,000 chemically sensitive patients.


The diagnosis of chemical sensitivity can now be made with a combination of the following history, physical examination, immune tests including IgE, IgG, complements, T & B lymphocyte subsets, blood levels of pesticides, organic compounds, heavy metals (intracellular), and occasionally objective brain function tests. Antipollutant enzymes, such as superoxide dismutase, glutathione, peroxidase, and catalase have been found to be suppressed in the chemically sensitive. Vitamin deficiencies, mineral deficiencies and excess, amino acid deficiency and disturbed lipid and carbohydrate metabolism has been observed.

Challenge tests are the cornerstone of confirmatory diagnosis. These may be accomplished through oral, inhaled, or intradermal challenges. Care should be taken to rule out inhalant problems with pollen, dust, and molds. Food sensitivity occurs in approximately 80% of the people with chemical sensitivity; and must be evaluated. When diagnosing chemical sensitivity, one must investigate water contaminant sensitivities, as 90% of people with chemical sensitivity have water contaminant reactions4. This can be checked by placing the patient on less chemically-contaminated, charcoal filtered, distilled, or glass-bottled spring water for four days, with subsequent rechallenge of the patient's regular drink water. This procedure will often elicit a reaction to the water pollutants in the sensitive individual. Patients frequently know where and when the onset of their problems occurred, e.g., sudden exposure to pesticides, working around printing machines and factory machines, etc. They usually develop increased odor perception to gasoline, perfumes, new paints, car exhausts, gas stoves, fabrics, clothing or carpeting stores, chlorine and chlorox, and cigarette smoke. Not only will they find these smells offensive, but may have marked reactions to them as well. Other symptoms can range from the almost universally-seen fatigue, to classic end-organ failures. Physical findings frequently are vascular in nature, with edema, petechiae, spontaneous bruising, purpura, or peripheral arterial spasm. Frequently there is flushing, adult-onset aerie, and a yellowness of the skin without jaundice. Chronic, recurring nonspecific inflammation is usually a significant sign, e.g., colitis, cystitis, vasculitis, etc. Laboratory findings are often non-specific, e.g., sedimentation rates may increase or liver profile may be mildly off. Fifteen percent of environmentally sensitive patients have positive C-reactive proteins. Twenty-five percent show abnormal serum complement parameters. Fifty percent of the chemically sensitive patients have depressed T cells. Twenty-five percent have impaired blastogenesis, and twenty-five percent have impaired delayed hypersensitivity, as evidenced by cell-mediated immunity skin tests. Of the patients with T-cell abnormalities, the depletion of the suppressor cells is seen, by over four standard deviations from a control group of normals. Ten percent of these patients have elevated IgE or IgG. Patients with recurring infections have impaired phagocytosis and killing capacity. Very accurate blood measurements are now available for the chlorinated pesticides as well.

The following were found in over 200 chemically sensitive patients:


DDT and DDE62.0%


Heptachlor Epoxide54.0


Endosulfan I34.0




gamma-BHC (Lindane)9.0





Endosulfan II1.5

Organophosphate levels are only positive within 24 hours after exposure, and are not much help. Lab tests for pentachlorophenols and organic solvents like hexane and pentane, are also now available, as are herbicide levels. General volatile organic hydrocarbons are found in a large portion of chemically sensitive patients. Their presence indicates either recent exposure, or a failure in the enzyme detoxification system. Those found in over 500 chemically sensitive patients include benzene, toluene, trimethylbenzene, xylene, styrenes, ethylbenzene, chloroform dichloromethane,

trichloroethane, trichloroethylene, tetrachloroethylene, dichlorobenzenes. Metals including lead, mercury, cadmium, and aluminum are sometimes found in the intracellular contents of some chemically sensitive patients. These again are found in 10% of the patients.

Fat biopsies have been preferred on many patients with over 100 different compounds studied. Often there is more in the fat than blood in some cases such as organochlorine insecticides and more in the blood than fat such as seen with such substances as 2-methylpentane and 3-methylpentane.

Skin biopsies of bruising and petechiae reveal perivascular lymphocyte infiltrates around the vessel wall in chemically sensitive patients.

Challenge tests can be done by the sublingual or intradermal route. The efficiency of these tests is now well established as numerous studies, (several double-blind), have now been done. These need to be done since 80% of the chemically sensitive are food sensitive. Blind intradermal challenge for chemicals can now be done with terpenes, petroleum derived ethanol, glycerine, formaldehyde, phenol, perfume, and newsprint, whereby production of symptoms will help establish the patient's chemical sensitivity.

Over 200,000 intradermal challenges of chemicals have been done under environmentally-controlled conditions at the EHC-Dallas. These are dearly reliable, especially as they meet the positive criteria of sign and symptom reproduction, wheal growth and negative placebo response.

Inhalation challenge is another method for the diagnosis of chemical sensitivity, done under varying degrees of environmentally controlled conditions. For best results, one uses an anodized aluminum and glass booth to do ambient dose challenge of any toxic chemical in a hospitalized, environmentally controlled setting. Some studies done in our center, under strictly controlled conditions in an environmental unit, showed significant findings (4 S.D.) of the chemical reactors over the controls when using less than .20 ppm formaldehyde, less than .0025 ppm phenol, less than .33 ppm chlorine, less than .50 ppm petroleum derived ethanol, less than .034 ppm of the pesticide, 2,4,DNP, along with 3 placebos. These tests have been used in over 3,000 patients with over 99% accuracy. Similar studies can be done in the office setting, although controls are much more difficult, and one finds many more placebo reactions. This is because environmentally-controlled conditions are generally much more difficult to achieve and patients are often studied in the masked or adapted state, wherein symptoms may not be perceived. With the inhaled challenges, one can measure and plot blood levels, immune parameters, metabolic changes as well as sign and symptom scores.

Vitamin and intracellular mineral levels are needed to completely evaluate the chemically-sensitive individual. In our Center, analysis of over 300 chemically sensitive patients showed the following vitamin deficiencies: 64% with B6 deficiency, 30% with B2, 29% with Bl, 27% with folic acid, 24% with vitamin D, 19% with B3, 6% with vitamin C, 3% with vitamin B12. Out of 190 chemically sensitive patients with mineral deficiencies, 88% had chromium deficiency, 12% selenium, 8% zinc, 40% magnesium and 35% sulfur. Many had mineral excess in their blood cells.


The cornerstone of treatment for chemical sensitivity is avoidance, avoidance, avoidance. Remove the cause or the patient must remove themselves or this condition can continie to degrade and often a person does not fully recover. Avoidance to known causes will decrease total body burden, allowing recovery of the overtaxed detoxification systems. Less chemically contaminated water (including spring, distilled, and charcoal filtered), may be used, but only in glass or steel containers. Water will leach a variety of contaminants from the walls of synthetic plastic containers. A rotary diet of less chemically contaminated food, should also be used to reduce load and keep the patient in the unmasked state. Remove as many household incitants as possible, including petroleum-derived heat, insecticides, synthetic carpets and mattresses, and formaldehyde-containing substances such as pressboard and plywood. Toxic exposures can be monitored by the general volatile organic hydrocarbon blood tests. Some job changes may be needed, while occasionally the most severely affected patients must leave badly polluted areas. Techniques should be developed for follow-up and monitoring of these modalities.

Injection therapy for inhalants, foods, and some chemicals will also help this problem. Low-dose sublingual therapy in patients with allergic rhinitis was effective. These treatments can be done daily, but usually every four to seven days. In our opinion, a properly balanced rotary diet is essential in treating the patient with food sensitivity, whether or not it may be induced by chemical overload. Vitamin and mineral supplementation is often necessary to replace the deficiencies that occur from the direct toxic damage, exhausted enzymatic detoxification pathways, and from the direct competition absorption. In rare cases, nutritional replacement with intravenous hyperalimentation is needed for severely debilitated patients. Techniques should be developed for monitoring and evaluating the outcome.


For physicians. The philosophy and techniques of environmental medicine developed over the last 25+ years offers a means to scientifically investigate and treat patients affected by man-made chemicals and pollutants. This approach gives the physician valuable, accurate information, in the pursuit of optimum health for these environmentally-sensitive patients. If you are a physician you have likely seen a significant increase in patients showing some of the symptoms shared and they likely know at least some of the initial causes. Anyone can become disabled by MCS/TILT. Doctors, lawyers, farmers all can be exposed and become affected. This disease is more serious and dangerous to the physical and mental health of the patient than many conditions that are treated with more care and respect. MCS/TILT should not be treated as just a series of allergies or mental condition. First and foremost, the condition deserves an abundance of empathy and consideration. When treating a patient with MCS it may require what may seem excessive allowances such as meeting in fragrance/chemical reduced examining rooms or even outside of the doctor’s office. 

For those affected. You are not crazy and it is now known that your body is rejecting the manmade chemicals around you in the worst way. For a while you will always be looking over your shoulder trying to figure out what is causing all these extreme symptoms. You are not alone. Get away from everything you know is hurting you. You will begin to feel and think better as you limit your exposures and get away from molds and man-made chemicals. This is often hard or may even feel impossible but the sooner you can achieve avoidance the better. This is often a lifelong condition and the longer you ignore it the worse it will get, and your recovery gets more difficult. There may be times when avoidance is not possible. Do all you can to make sure you eat right and drink safe water. Search MCS groups on Facebook for support and ideas on how to survive and thrive. Unfortunately, there are very few places to run. It is not uncommon for those suffering to live in their old car for a time. If your body and mind are shutting down, you may need to get a vehicle you can camp in. Hopefully you live in an area where you can find some great spots. I’m so sorry but hopefully you can get family and friends to help. 💛

We will be adding more resources and links soon. There is an ever-increasing number of doctors recognizing this disease however there are only a few binders and treatments they can provide. It is not uncommon for patients to require prednisone for a time. The reality is that the only real treatment is avoidance and that not onl includes the things you may know about. The things you must consider avoiding include pesticides new or used in the last 7 years, fragrances in all forms, petroleum products and gases, VOCS of many sorts including air pollution, smoke from most sources etc. Many patients can no longer wear polyester or use over the counter deodorants. 

Millions Report Negative Reactions to Perfumes and Fragrances.

While many of us are familiar with potential environmental hazards like pollution, exhaust fumes, and cigarette smoke, and acknowledge the risks associated with certain cleaning products, paint, glues, and stains, we may not have considered that our beloved perfumes and colognes could be causing discomfort for many.

It's often overlooked that these fragrances commonly contain a variety of chemicals deemed by many as toxic. Despite the general perception that scented products are pleasant, harmless forms of self-expression and not significant health concerns, millions are experiencing adverse reactions to them.

If you feel you may suffer from this disease you can start with these

tests: https://tiltresearch.org/qeesi-2

Some other sites with MCS Information:

Tree cellulose. How does wood mold get in my food? https://www.marketplace.org/2017/11/01/how-wood-got-our-food-then-out-it-then-back-it-again/?fbclid=IwAR1-hFl6pvH3IYIIHjWgpl2jFU8rdaY5wNaL0AthHwMH_5RRCGG-yS9MtpI




From previous periodicals

Multiple Chemical Sensitivity (MCS), also known as Chemical Sensitivity (CS), Chemical Intolerance (CI), Idiopathic Environmental Illness (IEI), and Toxicant Induced Loss of Tolerance (TILT), is a complex syndrome characterized by recurrent debilitating symptoms induced by environmental chemicals at doses typically considered harmless for most individuals. The symptoms span various organ systems and usually resolve upon removal of the environmental chemicals. The classification of MCS as a clinical entity is a subject of debate, despite substantial evidence supporting its existence.

Keywords: multiple chemical sensitivity, chemical intolerance, toxicant induced loss of tolerance, prevalence, etiologies, assessment, olfaction, psychopathology

MCS remains a contentious disorder in the USA, where patients experience illness due to exposure to low levels of predominantly petroleum-based and diverse chemicals, including pesticides, insecticides, cleaning products, detergents, diesel exhaust, formaldehyde, plastics, carpets, epoxy, and various synthetic and natural fragrances. Symptoms may manifest gradually over time from repeated low-level chemical exposures or, in some cases, immediately following a single high-level exposure. The phases of sensitization and triggering are often associated with aversion to specific stimuli and a subsequent broadening of symptoms to a wider range of odorous substances or chemicals. Common symptoms include hypersensitivity to chemical smells, nausea, dizziness, headaches, respiratory discomfort, eye irritation, chest pain, joint pain, fatigue, concentration difficulties, memory issues, depression, anxiety, mood disruptions, and other cognitive and psychological disturbances. Removing the offending agents from the environment frequently alleviates these symptoms.

Despite the prevalence of MCS, there are no standardized medical tests correlating with the multisystem complaints reported by patients. The underlying causes, whether biological or psychological, are primarily chemical but not fully understood. The elusive nature of MCS and the diversity of symptoms raise questions about its classification as a single clinical entity. MCS is often associated with other conditions lacking definitive diagnoses and explanations, such as fibromyalgia, Gulf War syndrome, chronic fatigue syndrome, sick building syndrome, and electromagnetic radiation exposure.

The interest in chemical sensitivity dates to the 1950s, with allergist Theron Randolph observing the role of environmental chemicals, pollutants, and certain foods in allergic reactions leading to various physical and psychological diseases. Randolph's Clinical Ecology, though considered pseudoscience by some in the medical community, laid the foundation for the understanding of chemical sensitivity. The term Clinical Ecology has seen renewed interest in medical movements emphasizing the interplay between individuals, their microbiome, and broader social, political, and economic ecosystems influencing health.

Cullen's operational criteria in the 1980s provided a basis for defining MCS, emphasizing acquired disorders following environmental exposure to chemicals, symptoms involving multiple organs, reactions to predictable classes of chemicals or odors at non-harmful doses, and the absence of correlation with routine medical tests. Lacour et al. later extended these criteria, adding guidelines related to the central nervous system involvement, persistence of symptoms for at least six months, and impacts on social and occupational lifestyles.

Demographically, individuals with MCS tend to be well-educated, of higher socioeconomic status, and middle-aged. Women are more commonly affected than men, and the prevalence rates vary based on the context of data collection, ranging from <1% to 33%. The elusive nature of MCS and its similarity to other disorders contribute to the challenges in establishing accurate prevalence rates.

In summary, MCS remains a complex and controversial syndrome characterized by debilitating symptoms induced by environmental chemicals. The classification debate continues, and despite challenges in prevalence assessment and diagnostic criteria, the impact on individuals' lives is evident.

Before I go into detail about Chemical Sensitivities, it is important to note that most chemicals and fragrances are potentially harmful to anyone, not just a person with CS. Unfortunately, modern society has chosen to use many dangerous chemicals and synthetic substances that our bodies do not have the innate ability to detoxify. There is a great deal of research into the potential long-term effects of our continuous exposure to chemicals and fragrances, much of which points to a possible correlation with the increased prevalence of cancer and other terminal illnesses, asthma and other respiratory diseases, cognitive issues and learning disabilities/developmental delay (including autism), mental health and behavioral problems, and many other illnesses. Many of the chemicals and fragrances in our everyday products are neurotoxins (damage the nervous system and brain), endocrine disruptors (disrupt the normal functioning of hormones), carcinogens (contribute to the development of cancerous cells), hepatotoxins (damage the liver), mutagens (alter the DNA in cells), allergens (cause allergic reactions), reproductive chemicals (affect fertility), and teratogens/embryotoxins (interfere with the normal development of an embryo or fetus). For more information and links to various research, please read the Causes section below as well as Why Is Fragrance-Free/Non-Toxic Living So Important: Health Risks for All Individuals.


Chemical Sensitivities (CS) - also known as Multiple Chemical Sensitivity (MCS), Environmental Illness, or Chemical Injury - is a chronic condition in which a person develops various adverse symptoms from exposure to chemicals in their environment. Although healthy people often react to toxic substances, the difference is that a person with CS has much more severe, debilitating, and prolonged symptoms and also reacts to much smaller amounts of chemicals. Their reactions are repetitive and reproducible, and symptoms are generally relieved after the toxic chemicals are removed or within a consistent amount of time thereafter. Chemical Sensitivities affects approximately 12 - 30% of the population, depending on the source consulted. (Sources: 1, 2, 3)

What do we mean by “chemicals?” Obviously, everything around us is made of certain chemicals, including our bodies, the trees in our backyard, and the stars in the sky. Not all chemicals are harmful. In general, what I am referring to on this website are those chemicals that are synthetic or man-made. However, this distinction is not always clear as many naturally occurring substances can be toxic to the body as well, including lead, mercury, aluminum, arsenic, and radon.

Fragrance chemicals, specifically, tend to cause some of the greatest difficulty for a chemically sensitive person. When the word “fragrance” is listed in the ingredients of a product, it is a generic term that can represent literally hundreds of chemicals and chemical combinations. Fragrance chemicals are designed to stick to people’s skin and clothes, and also to waft long distances through the air – that is why they create such problems for the chemically sensitive person. Some synthetic chemicals are only a health risk to the person using them. But many are a health risk to everyone around that person as well. An example of this is fragrance chemicals - you cannot use them without negatively affecting the health of everyone around you.

It is also important to note that a chemical does NOT have to have a strong smell in order to be toxic. In fact, many dangerous chemicals are completely odorless. (Yes, the name of this website is a bit of a misnomer!)

The following is a list of many of the specific products and chemicals that can cause a chemically sensitive person to have a reaction.

- Perfumes and colognes
- Fragranced laundry detergent (on their clothes or somebody else's)
- Fabric softener and dryer sheets (even if fragrance-free, these still contain chemicals that
   are carcinogens, narcotics, neurotoxics, and "hazardous waste" as classified by the EPA)
- Fragranced hand and body lotions, soap, and shampoo
- Most commercial air fresheners (including Febreeze, which contains over 80 KNOWN toxic
- Cigarette smoke and smoke from woodstoves, campfires, burning leaves, etc.
- New carpeting, furniture, or flooring, and other household furnishings and fixtures
  (all contain a multitude of chemicals that “off-gas” into the air)
- Toxic household mold and mildew
- Ink, toner, magazines, newspapers, and other printed materials
- Petrochemical fuels, including diesel, gasoline, and kerosene
- Cleaning products made with harsh detergents, solvents, or fragrances
- Pesticides and herbicides (both in food and in the air)
- Paints, glues, and sealants
- New clothing and fabrics (these are processed with many chemicals, including
- New electronics or appliances (both internal and external parts off-gas very strong
- Chlorinated water in swimming pools 
- Fluoride, chlorine, and other chemicals found in drinking water
- Excessive quantities of dust and dust mites
- Artificial colors, flavors, sweeteners, and preservatives in food
- Residues of chemicals and fragrances on someone's clothing or hair
- Cats, dogs, and other animals

Also be sure to check out the American Academy of Environmental Medicine's definition of Chemical Sensitivities.


The chemicals in our environment and everyday personal care products affect multiple organs and bodily systems, including the immune, central nervous, respiratory, endocrine, digestive, musculoskeletal, and reproductive systems. Thus, the symptoms of Chemical Sensitivities vary greatly amongst different individuals. The most common symptoms include: headaches, migraines, or sinus issues; extreme fatigue, weakness, and loss of energy; cognitive dysfunction such as difficulty concentrating, memory loss, and  severe disorientation, commonly referred to as “brain fog”; dizziness, vertigo, and  heart palpitations or arrhythmia; nausea and vomiting; itching, burning, rashes, hives, and other skin irritation; difficulty breathing, coughing, congestion, and sore throat; muscle and joint pain; and many other symptoms. In severe cases, one can even experience seizures, loss of consciousness, or anaphylactic shock (an extreme allergic reaction that can involve heart failure, circulatory collapse, and/or severe asthma-like breathing difficulty). These symptoms are often triggered from exposure to minute amounts of chemicals, such as a friend who is wearing perfume or whose clothes were laundered in fragranced detergent and dryer sheets.

Although many people, including healthy people, may have small reactions to certain chemicals, such as getting a headache after sitting next to someone wearing perfume, the experience is very different for a person with CS. For most chemically sensitive people, these symptoms are very severe, persistent, and debilitating. They may have chronic brutal headaches that last day in and day out for months or longer. They may be so tired and weak that they literally cannot get out of bed - lifting their arms and legs feels like an astronomical effort and they literally cannot do it. Or the cognitive symptoms may become so severe that they cannot organize or understand their own thinking - they have difficulty following a train of thought to its completion, they struggle to carry on a normal conversation, they are disoriented and lose brief moments of consciousness, and cannot drive safely. Difficulty breathing may lead to anaphylactic shock, and many other symptoms can also become very extreme and debilitating.


As mentioned above, chemicals and fragrances are harmful to all people, whether that harm is noticeable or not. Why someone would develop a noticeable sensitivity to chemicals and fragrances is the subject of this section.

Chemical Sensitivities can occur on its own or it can be a symptom of  another illness which has weakened the body, its immune system, and its detoxification pathways. Chronic infections are a huge factor in the development of CS - they are much more common than most people think and are generally undiagnosed. These include chronic viruses (i.e. Epstein Barr, Cytomegalovirus, Parvovirus), chronic bacterial infections (i.e. Lyme Disease and its coinfections, Streptococcus, Staphylococcus), parasites (yes, surprisingly common), yeast overgrowth (Candida), fungal infections, and gut dysbiosis in any form. Biotoxin illness from infections or from mold exposure is also a huge factor which requires very specific treatment (see www.survivingmold.com for details).

Other illnesses than can cause a sensitivity to chemicals or fragrances include Asthma, AIDS, Cancer, Chronic Fatigue Syndrome, Fibromyalgia, Addison's Disease (or secondary adrenal issues), Mast Cell Activation Syndrome, sinus problems, autoimmune disorders, heavy metal toxicity, unidentified allergies, leaky gut syndrome, etc. The reverse is also true - the chemicals in our environment can contribute to the development of many of the above diseases as well - either directly (by causing direct damage to the affected bodily systems) or indirectly (by weakening the body's defenses and making a person more susceptible to illness). Various inherited genetic defects can also be a cause of CS - a mutation of the MTHFR gene, for example, can severely inhibit the body's detoxification abilities.

There is a lot of debate regarding the cause of Chemical Sensitivities when not caused by another illness. This is largely due to the lack of attention given to this condition by doctors and medical research organizations. However, the consensus is that CS is commonly caused by one high-dose exposure to a certain chemical or combination of chemicals, or by chronic and repeated exposure to any amount of a chemical or combination of chemicals. In our society, chemical exposure is impossible to avoid; therefore, we are all at risk for developing CS and should engage in regular detoxification efforts and pay close attention to our environment, our diet, the products, we use, etc.

There are a couple of different theories as to why chemical exposures would lead to the development of CS.

With the “total load” theory, the idea is that the body has a relatively finite space to work with and the detoxification pathways, specifically, have a certain capacity of how much toxic material they can remove and how quickly. Since we are exposed to and absorb such an overwhelming amount of toxins, the body cannot effectively remove it all and trace amounts are left behind. Even a healthy person cannot effectively process and remove everything. The toxic material left behind builds up and is stored in fatty tissues and other areas of the body. The more build up there is, the less efficient the body becomes at detoxing from new exposures. Eventually a tipping point is reached and the body is so severely hampered in its detoxification process that symptoms or illness develop. Just our daily exposure to everyday toxins can be enough to actually cause Chemical Sensitivities - our bodies simply can't keep up with the modern chemical load.

The most commonly reported exposures that trigger the onset of CS are indoor air pollution. This can include a variety of specific exposures, including moving into a new home with brand new paints, stains, sealants, carpeting, pressure-treated wood, and other new materials or furnishings; working in a new or recently renovated building; having toxic mold and mildew in your home or workplace, or other contaminants such as radon, asbestos, carbon monoxide, lead-based paint, or poorly contained heating fuels; or working in a profession where you are regularly exposed to  toxins, such as construction, agriculture, transportation, automotive repair, cosmetology, etc. (Office work can also be a toxic profession if you sit close to a printer or photocopier.) In some of these situations, especially the case of toxic mold, a person is often given the diagnosis of Sick Building Syndrome, a condition whose symptoms are generally identical to Chemical Sensitivities. Once the contaminants are removed, it is likely that the person's health will improve, but sometimes the damage is so severe that it can take years or even decades to reverse; in some cases, it may be permanent.

Occupational exposure is also a commonly reported trigger of the onset of CS. Many professions involve use of or contact with particular chemicals, including construction and manufacturing, hospital and other medical work, landscaping and lawn care, cosmetology and beauty salons, printing and general office work, mining, and many more.

Outdoor air pollution, especially when living in a large city or a heavily polluted area, can also be a significant load on the body, as can the many daily exposures that we don’t even think about such as secondhand smoke, residential pesticide or herbicide use, and pesticide residue in our foods. Local spraying of pesticides is also a common trigger of CS.

It is important to note that Chemical Sensitivities is not about a person simply disliking smells or fragrances. It is about the chemical composition of these smells; natural scents are generally not a problem for people with CS. It also is not a psychological reaction. It is a real, physiological reaction to chemicals in the environment, and these reactions often occur without the person's awareness of the presence of these chemicals.


It can be difficult to recover from Chemical Sensitivities, but it can be done if you are dedicated and patient. Possibly the most difficult part of it is determining what you have to do to get better.  There has not been enough solid medical research conducted about CS and many, if not most, doctors do not know how to treat it. People with CS often end up going from doctor to doctor trying to find a solution and spending lots of money trying a multitude of supplements, treatments, or medications that are recommended to them. They often end up conducting their own research and, in effect, becoming their own doctor. Unfortunately, many chemically sensitive people become sicker as time goes on and do not improve. But it is possible to get better or at least to dramatically decrease the level of sensitivity. In my experience, and from what I understand about others' experiences, recovery is much more successful when using a holistic approach and working with a combination of traditional medical doctors (such as a primary care physician, allergist, immunologist, nutritionist, or other specialist) and alternative practitioners (such as a naturopath, homeopath, chiropractor, acupuncturist, or energy healer). If you are willing to investigate multiple approaches and to explore both physical and mental/emotional healing, you will most likely get better results.

The two most common methods of treatment for Chemical Sensitivities are avoidance and detoxification. Avoidance means literally staying away from all fragrances and other toxic chemicals as much as possible. Although this will help a person's health a lot, it is virtually impossible unless the person wishes to have no home, no car, no job, no bed, no clothes, no books, no computer, and definitely no social life. (For more on this topic, please see Can You Avoid Chemicals?.) It is very important to eliminate as many toxic exposures as you can, just remember this is not the cure. Some of the heaviest toxins that people are regularly exposed to include: household mold and mildew, chemically based building materials (fresh paint, floor varnish, pressure-treated wood, etc.), household carpets (especially if new), perfume/cologne, scented laundry detergent, dryer sheets, fabric softener,  air fresheners, and cigarette or wood stove smoke. It is important for EVERYONE to avoid these things as much as possible. Without eliminating these, healing will be slow or non-existent. (For more on this topic, please see How to Go Fragrance-Free/Non-Toxic.)

The next step is to treat any underlying conditions which contribute to the Chemical Sensitivities. In many cases, CS will not improve without treating these underlying conditions.  See the full list in the Causes section above. The two most common underlying conditions, in my experience are:

Chronic infections - These are much more common than you would think! And are usually undiagnosed. These include chronic viruses (i.e. Epstein Barr, Cytomegalovirus, Parvovirus), chronic bacterial infections (i.e. Lyme Disease and its coinfections, Streptococcus, Staphylococcus), parasites (yes, surprisingly common), yeast overgrowth (Candida), fungal infections, and gut dysbiosis in any form. Biotoxin illness from infections or from mold exposure is also a huge factor which requires very specific treatment (see www.survivingmold.com for details). For many with CS the more they treat the underlying infections, the healthier they get.

Genetic defects that interfere with your body's detox pathways. Surprisingly, a huge portion of the population has these defects. If even one portion of your detox pathways is not functioning correctly, your body will not detox well on its own and using a sauna or doing a cleanse won't be very effective. It's common to feel worse while detoxing, but if you feel awful even after detoxing consistently for years, then there is probably a genetic defect at play. These defects can't be "fixed" per se, but they can be circumvented with supplements and nutrition. You can do your own genetic testing through 23andme.com and then work with a Naturopath (or a doctor that incorporates natural medicine) with a good understanding of genetic issues, specifically related to detox pathways.
A good example of underlying conditions is Lyme Disease. The Lyme bacteria is constantly releasing neurotoxins into the body and overloading the body's detox pathways. If your detox pathways are already compromised by a genetic issue as mentioned above, this will make things even worse. Lyme also interferes with the optimal functioning of many (if not all) bodily systems. Without killing off the Lyme bacteria (which will take a concerted effort and multiple types of treatment), the body will remain in toxic overload and be unable to heal from CS.

If you believe that your CS may be caused by or exacerbated by another condition or weakness in the body, work with a practitioner who can identify these weaknesses and help bring you back into balance. In my experience, Naturopaths have the best comprehensive understanding of all the different components involved in this type of healing, however other types of doctors can certainly help as well.

The next step is to work to detoxify the body as much is possible. This decreases the total load of chemicals that one carries around on a daily basis and can help many people with CS to become less reactive. Detoxification is a much more complex process than is commonly understood. It is very important to work with a doctor or health care practitioner who fully understands this. Common methods of detoxing include chelation; saunas; dietary changes; colon, liver, or digestive system cleanses; specific vitamins, minerals, and antioxidants (i.e. the correct form of B12 for your particular genetic makeup, or certain precursors to glutathione, which is your body's master antioxidant and detoxifier); specific herbs, high quality essential oils, and other natural supplements (i.e. lemon oil, milk thistle, dandelion root, bentonite clay, and a good quality probiotic); removal of mercury amalgams; and many alternative medicine treatments such as acupuncture, homeopathy, energy work, and ionizing foot baths. Most people find that a combination of body detoxification and avoidance of chemicals and fragrances works best. Drinking lots of water is also important, as is replenishing essential nutrients lost during chronic illness and extensive detoxification.

3) Chemical Sensitivities is a social disease. It has been created by a society that continually chooses to manufacture its products and conduct its industries using incredibly hazardous chemicals. It is becoming more prevalent as more and more chemicals are used. And since we created it, we can put an end to it. Possibly more than any other illness, you have the power to help people with Chemical Sensitivities. Their lives are in your hands. Every person who stops using fragranced products is making a difference. Every organization that stops polluting the air we breathe or tries to detoxify their workplace is making a difference. This is what it is going to take. One by one, people have to start caring enough to make changes in their lives. For many individuals, these changes require very little effort yet are incredibly large in effect. (For more discussion on this topic, please see Why Is Fragrance-Free/Non-Toxic Living So Important? and How To Go Fragrance-Free/Non-Toxic.)

My goal with this website is to educate people about the daily experiences of people living with CS and how imperative it is that more and more people begin to live as fragrance-free as possible. This is a very serious, debilitating, and life-changing condition. It is real, it has genuine causes, and very devastating consequences. It's time to stop debating about whether or not Chemical Sensitivities is "real" and start putting that energy into fixing the real problem. If we, as a society, don't decrease our use of fragrances and chemicals, the prevalence of this illness will continue to rise. People with CS are like the canaries used in coal mining - if they are getting sick, everyone else should pay attention.

Living with Chemical Sensitivities can be anything from an annoying inconvenience to an unbearable daily nightmare depending on the severity of the condition. Someone with very mild sensitivities may be able to function quite well in society. They may experience symptoms only briefly and intermittently and may only have reactions when exposed to extremely potent substances or very large quantities of chemicals and fragrances.

However, the experience of CS varies greatly, and many individuals suffer from moderate to very severe symptoms that create radical limitations in their daily living. They often react to very small amounts of chemicals and fragrances in their environment and become quickly debilitated when exposed to common personal care products, smoke, and industrial chemicals. Many have reactions that last several days or longer after an exposure and, as the condition worsens, many become so sick that they experience symptoms all the time. Chemically sensitive people who don’t respond to treatment have to be very careful to avoid peoples, places, and things that would trigger a reaction and because of this, many become partially or completely housebound.

To fully understand what it is like to live with Chemical Sensitivities, it is important that you understand the concept of “off-gassing.” When a new product contains chemicals, it releases those chemicals into the air for a certain period of time. This is known as off-gassing or out-gassing. People with CS generally have difficulty with anything new and often need to wash and soak these products multiple times or leave the products outside or in another room for many weeks or months before they can use them. This includes new clothes, books, blankets and other bedding, mattresses and other furniture, computers and other electronics, housing fixtures, appliances, etc.
Let’s take a detailed look at how living with CS affects each area of a person’s life.


It is often incredibly difficult for someone with Chemical Sensitivities to find safe housing, meaning a home, apartment, or other living situation that will not exacerbate symptoms. There are numerous chemicals used in building, furnishing, and maintaining a house or apartment building, and for someone with Chemical Sensitivities, these can affect the body for many years after construction. They generally have to look for a house that is old enough to have off-gassed these chemicals or one that was built with natural, untreated materials; however, even then there are issues to consider. The presence of any amount of mold, which is highly toxic to the body, is especially difficult for people with CS.

It can take years to find a safe environment and because of this, many individuals end up temporarily or even permanently homeless or get stuck living in a place that exacerbates their symptoms and makes them progressively more ill due to the chronic exposure. Once a safe spot is found, there is still the trouble of finding safe ways to maintain and repair it, especially in rental situations where the landlord makes the decisions regarding what types of maintenance products to use.
The list below shows some of the many things a person with Chemical Sensitivities has to consider when looking for a place to live: 

Does the place have carpets? New or semi-new carpets off-gas many toxic chemicals, including formaldehyde. Old carpets can easily absorb and trap dust, smoke, mold, and other contaminants.
Does the place have any mold? It can be incredibly difficult to find housing with absolutely no mold, especially in certain geographical areas more prone to it. Mold can trigger many intense and incapacitating symptoms and is a common trigger of the onset of CS.
How is the level of outdoor air pollution in the area? Cities have higher levels of exhaust, continuous paving and other road work, and more people, which means more fragrances, smoke, etc. Rural areas can have different issues, such as higher mold and mildew in the air as well as the use of pesticides and similar products for farming and gardening. In any area, one needs to assess how close they are to neighbors and whether these neighbors use strong scented laundry products, use a wood stove for heat, or burn leaves or have campfires often? Smoke and laundry chemicals can travel quite far in the outdoor air and make it impossible for a chemically sensitive person to be outdoors, even on their own property. In some situations, these chemicals can even seep into the home.

Has there been any recent remodeling or refinishing such as new flooring, new windows, or fresh paint? This can be an especially difficult issue - people like to make a place look nice before they attempt to sell or rent it, but generally aren’t aware that they are lacing it with toxic products.
What kind of heat is used? Many people are sensitive to specific kinds of heat (such as propane, gas, wood stoves, etc.) and certain types (such as forced hot air) tend to carry more dust with them.
Are you going to have roommates? Do they use perfume, scented laundry products, soaps, lotions, or other problematic products? Do they use strong cleaning products and are they willing to use anything different? Do they smoke?
Do other tenants smoke in the building or on the grounds? Smoke carries through windows and walls very easily and even small amounts can cause huge problems for a person with CS.
Is there a shared laundry facility on the premises? If so, what floor are you on and how close is the laundry window to your window(s)? Laundry products are some of the most potent offenders and can affect a person from quite a distance. Also, where are you going to do your laundry? People with CS generally cannot use public Laundromats or shared laundry facilities, and unless they have the money for their own washer and dryer, many often end up hand-washing their clothes in the tub or sink.
Is the place furnished? If so, it will be important to make sure the furniture is not brand new (as it will off-gas chemicals for a long time if this is the case) and also that it has not absorbed chemicals or other contaminants from the previous owner (such as pet dander, wood stove or cigarette smoke, cleaning products, mold or mildew, and even perfume and scented laundry products).
There is also the option of building a new house with only environmentally safe and low-chemical, natural based materials and furnishings. However, this is very costly and most people with CS are very low-income because of the inability to work much (or at all), and the difficulty in obtaining SSDI or Worker’s Compensation.

There is now a wonderful non-profit called Re-Shelter dedicated to helping people with Chemical Sensitivities find and afford safe housing and encouraging the advancement of more natural building materials in home construction. Please check out their site for lots more information. 


People who have severe Chemical Sensitivities generally experience great difficulties in work. Sometimes work exposures are what make them sick to begin with. Other times, a toxic work environment makes them progressively worse, and they eventually have to leave. Sometimes they can’t find a job in a safe building, or they are just so tired and wiped out from this illness that they don’t have the energy or stamina to work.

Here are some of the many substances in the workplace that can trigger a reaction in a chemically sensitive person:

Once the items have been purchased, there is still a long way to go. Most products are full of chemicals that have been used in their production, and therefore need to be off gassed for a considerable amount of time before they can be used. This includes clothing, books and magazines, blankets and other bedding, couches and other furniture, computers and other electronics, housing fixtures, and appliances. Because of this, it can take a very long time to find products that will be safe for the chemically sensitive person. Some will take just a few days or weeks to off-gas, but many can take several months or longer before the person can be around them without getting sick.

Clothing is especially tricky. When bought new, it is laced with all the chemicals used in production, including formaldehyde. Clothing made from cotton and other natural fabrics often contains remnants of the pesticides used in growing the fibers. Synthetic fibers like polyester, rayon, and nylon, are chemically based and generally to be avoided. Even used clothing is a problem as it usually contains the chemicals and fragrances from the previous owner’s personal care and laundry products. People with CS have to wash and soak new clothing dozens of times before it is wearable, or they may purchase clothing made from organic fabrics and more natural production practices. Sadly, there are severely chemically sensitive people who end up spending most of their time naked.


There is also the constant stress of going to doctor after doctor and trying so many different treatments, especially when most doctors’ offices can make a chemically sensitive person sick. Many are trying to navigate the health care system with very little energy and often, because of how little recognition and understanding this condition gets in the medical community, they end up having to be their own doctor and do a lot of their own research on top of everything else.

Add to this the enormous financial stress of being disabled by a condition that most governmental and social service agencies don’t even believe is real, and therefore being unable to get financial support or having to exhaust themselves in the process. Many can’t even afford safe housing (or there isn’t any available) and end up living in a home that is actually worsening their condition day by day.

People with CS are almost always under a great deal of stress and are constantly expending more energy than they have as they search for ways to get better, ways to avoid getting worse, ways to cope with pain and sickness, safe places to be, safe products to buy, ways to be in the world without getting sick, and ways to maintain any sense of meaning and fulfillment from their lives.
Can You Avoid Chemicals?
How hard is it for a chemically sensitive person to avoid the chemicals that will trigger a reaction? The short answer is – ridiculously hard. It is virtually impossible to do so unless you are okay with having no home, no car, no job, no bed, no clothes, no books, no computer, and no social life. For someone with severe Chemical Sensitivities, it is even harder because very low levels of a chemical will trigger a reaction and cause symptoms. Keep in mind that most chemical exposures occur by breathing in a chemical that is in the air. This makes it more difficult to be aware of and have control over the chemicals one is exposed to. It is not very difficult for a chemically sensitive person to stop using chemicals and fragrances themselves, but they have no control over what others use. Another factor that makes it difficult to control what chemicals one is exposed to is the lack of full ingredient disclosure on many products. (For more information on ingredient disclosure, check out this excellent video interview with Dr. Anne Steinnemann, an independent researcher and professor of civil and environmental engineering.)

To illustrate the vast prevalence of toxic chemicals, let’s take a more detailed look at four specific types of chemicals/toxins, what products they are used in, and how we are exposed. There are many other sources of these chemicals and many other chemicals aside from these four; but this will give you a good idea of the incredibly widespread use of toxic chemicals.

1) Formaldehyde – Formaldehyde is a petrochemical, meaning it is derived from petroleum (see #3 for more information on petrochemicals). Formaldehyde is released as a gas into the air from formaldehyde containing products. It is commonly agreed upon that formaldehyde is toxic to the body and the International Agency for Research on Cancer has listed it as a known carcinogen. Commonly recognized symptoms of formaldehyde exposure include breathing difficulties, chronic headaches, central nervous system disorders, and when in contact with the skin, burns and irritation. However, it is still used in an alarming assortment of products and is a common trigger of very disabling symptoms for someone who is chemically sensitive. The following is a non-inclusive list of formaldehyde containing products:

  Household and automobile carpeting
  Plywood, particle board, and other pressed wood products (furniture, cabinets, etc.)
  Household insulation
  Fuel burning stoves and heaters
  Smoke (from cigarettes, wood stoves, and camp fires)
  Resins, glues, and adhesives (flooring glue, wood glue, and even some craft glue)
  Air fresheners and disinfectants
  Polymers and plastics
  New clothing, bedding, and other textiles and fabrics
  Fertilizer, fungicide, and germicide
  Paints and dyes
  Cosmetics, laundry detergents and fabric softeners, hair products, and body soaps
  Paper products
  Electrical appliances and components    
2) Fragrance Chemicals – When the word “fragrance” is listed in the ingredients of a product, it is a generic term that can represent literally hundreds of chemicals and chemical combinations. Unfortunately, there is no FDA requirement for full disclosure of these chemical ingredients. Fragrance chemicals are designed to stick to people’s skin and clothes, and also to waft long distances through the air – that is why they create such problems for the chemically sensitive person. These are possibly the most harmful types of chemicals as well as the hardest to avoid. You can read “Not So Sexy: The Health Risks of Secret Chemicals in Fragrance” published by the Campaign for Safe Cosmetics for more information. 
Here is a non-inclusive list of products containing fragrance chemicals:

 Perfume and cologne
 Shampoos, hair spray, and other hair products
 Soaps, lotions, and creams
 Scented laundry products (detergent, fabric softener, and dryer sheets)
 Cosmetics (blush, foundation, powder, lipstick, chap stick, mascara, etc.)
 Air Freshener in spray or plug-in form, including Febreeze
 Candles and incense
 Household cleaning products 
 3) Petrochemicals – The term “petrochemicals” refers to several thousand distinct chemicals derived from petroleum (crude oil) or natural gas. Formaldehyde, noted above, is an example. But as we look at this broader category, we see that petrochemicals are virtually everywhere. A few names you might have heard include ammonia, chlorine, methane, propylene, ethanol, benzene, butane, acetone, polymers, phthalates, dioxin, detergents, solvents, surfactants, BPA, DEA, and PABA. There are many more. Petrochemicals have been linked to many negative health effects, including asthma, cancer, birth defects, brain and nervous system damage, kidney, liver, and other organ damage, and disruption of endocrine function.
There are far too many sources of petrochemical exposure to list here, but let's take a look at some of the most common ones:

  Household cleaners, detergents, and disinfectants
  Pesticides and fertilizers (and therefore our food and water)
  Soaps and shampoos, lotions, creams, and body oils
  Cosmetics, including nail polish and remover
  Sunscreen and insect repellant
  Dryer sheets and fabric softener
  Gasoline, Kerosene, Diesel fuel, and Propane
  Synthetic fibers, rubbers, and fabrics (polyester, nylon, etc.)
  Paraffin wax or oil (candles, crayons, etc.)
  Hard plastics such as dishes, electronics, etc.
  Soft plastics such as garbage and shopping bags
  Flooring (vinyl, tiles, etc.) 
4) Metals & Heavy Metals – There are many naturally occurring metals, some of which are termed "heavy metals" due to their specific gravity. Some metals are required by the body, in small amounts, for healthy functioning (i.e. iron, copper, manganese, zinc). Other metals are very harmful and toxic to the human body (i.e. arsenic, aluminum, lead, mercury) and very difficult to remove from the body as well. Heavy metal toxicity can cause significant damage to many organs and body systems, including the brain, lungs, kidneys, liver, central nervous system, and the body's ability to detoxify. There is significant research suggesting that long-term heavy metal exposure can lead to physical, muscular, and neurological degeneration that mimics Parkinson's Disease, Alzheimer's Disease, Muscular Dystrophy, and Multiple Sclerosis. There is also research that linking certain metals to increased risk of cancer.

The following lists only a few of the many heavy metals and just a sampling of the common methods of exposure.

Mercury: Dental fillings, some vaccinations, some fish/seafood and supplements made from fish/seafood (i.e. fish oil), older paints or painted surfaces,  sewage sludge, and occupational exposures such as mining/processing of mercury, gold, or silver.
Aluminum: Cookware, antacids, anti-perspirants, aluminum cans, baking powder, cigarette smoke, car exhaust, paint, aspirin, many medications, many infant formulas, some forms of table salt, some toothpastes, some baby powder, and some food additives.
Lead: Car exhaust, wood smoke, cigarette smoke, hair dye, cosmetics, newsprint, contaminated water, lead-based household plumbing, older lead-based paints, PVC plastic, paint pigments, pesticides, and occupational exposures such as construction work, smelter operations, and radiator repair shops.
Arsenic: Contaminated water, contaminated shellfish, pesticides, fungicides, paints, wood preservatives, rat poison, and occupational exposures such as industrial smelting and manufacturing processes.
Cadmium: Cigarettes, insecticides, fungicides, fertilizers, batteries, PVC plastics, paint pigments, dental alloys, motor oil, car exhaust, and occupational exposures such as industrial ore smelting.
The above four categories of chemicals and their prevalence illustrate how difficult it is to avoid exposure to toxic chemicals. They are just about everywhere. So you can understand the frustration when a chemically sensitive person is told that “avoidance” is the best (or possibly only) way to get better. This is why it is so important for every individual to do their part by eliminating as many chemicals and fragrances as possible in their daily lives. Every person plays a part, and every action makes a difference. You have powerful choices to make. You can change people’s lives if you are only willing to make a few minor changes yourself. For more information, please see Why Is Fragrance-Free/Non-Toxic Living So Important? and How To Go Fragrance-Free/Non-Toxic.


Millions Report Adverse Reactions to Perfumes and Fragrances.


While most of us are familiar with potential environmental hazards such as pollution, exhaust fumes, and cigarette smoke, as well as the risks associated with certain cleaning products, paint, glues, and stains, it might not have crossed our minds that the delightful fragrances of our perfumes and colognes could be causing discomfort for many.

Unbeknownst to many, these fragrances often contain a variety of chemicals that are considered toxic by a significant number of people. Despite the general perception that scented products are pleasant and harmless means of self-expression, not posing a significant health concern, millions are reporting adverse reactions to them.

The composition of perfumes has evolved over time. Originally crafted from natural ingredients like flowers and herbs, modern perfumes are now approximately 95-100% synthetic. These synthetics, derived from chemical reactions using base materials like crude oil or turpentine oil, are often deemed hazardous when inhaled or applied to the skin.

Author Connie Pitts highlights the presence of harmful chemicals in perfumes, including those listed on the EPA's Hazardous Waste List, carcinogenic substances, neurotoxins, respiratory irritants, solvents, aldehydes, untested petrochemicals, phthalates acting as hormone disrupters, narcotics, and more.

A 1991 EPA study identified numerous volatile organic compounds in fragrance products, causing a range of health issues when inhaled, such as central nervous system disorders, dizziness, nausea, respiratory problems, and fatigue. Specific chemicals like toluene and methylene chloride, both hazardous substances, have been detected in fragrance samples.

The Committee on Science & Technology reports that about 95% of fragrance chemicals are synthetic compounds derived from petroleum. Petroleum-based chemicals are increasingly linked to various health issues, including cancers, neurological disorders, immune system weakening, autoimmune disorders, asthma, allergies, infertility, miscarriage, and child behavior disorders.

Synthetic fragrances are pervasive in everyday products, including soap, shampoo, deodorant, lotion, candles, air fresheners, laundry, and cleaning products. Even seemingly innocuous scents may contain potentially toxic substances, with some scented candles, for example, containing acetone, benzene, lead, carbon monoxide, and toluene.

Phthalates, found in everyday items like hair spray, deodorant, nail polish, and perfume, are associated with permanent birth defects in the male reproductive system. Despite the potential risks, the fragrance industry operates with minimal regulation, considering fragrance formulas as trade secrets, and compliance with safety recommendations is voluntary.

The impact of these chemicals extends beyond mere annoyance for many individuals. Fragrance exposure can exacerbate health conditions such as asthma, allergies, migraines, chronic lung disease, and multiple chemical sensitivity (MCS). Those with MCS experience chronic symptoms across various organ systems, making them particularly susceptible to even low concentrations of common chemicals.

While some may not immediately notice the effects of fragrance exposure, the long-term chronic health effects remain poorly understood. Fragrances are known to trigger migraines, allergies, and asthma. The Institute of Medicine equates fragrance to secondhand smoke in triggering asthma.

The rising number of Americans with MCS indicates a growing concern, with individuals developing sensitivity after initial exposure to toxic chemicals. Fragrance, even when not perceptible, may still be present and affect individuals, given that olfactory receptors can be overwhelmed, leading to decreased acute detection.

Inhaling fragrance chemicals has a direct impact on the brain and circulatory system. Moreover, since fragrance chemicals are absorbed through the skin, they can affect other organs, potentially causing discoloration and toxicity to the liver and kidneys.

In light of these considerations, it becomes crucial to assess our environment comprehensively. Even if we personally do not experience noticeable reactions to chemical fragrances, being considerate of others whose lives are significantly affected by our choice to use such products is a step toward creating a healthier and more empathetic community.


People with multiple chemical sensitivity (MCS) are made sick by exposures to low levels of many common chemicals – such as perfume, pesticides, tobacco smoke, fresh paint, new carpets, air “fresheners,” new building materials, vehicle exhaust, solvents, industrial fumes, and many cleaning products.  Many of these chemicals can make anyone sick at high levels, but chemically sensitive people can become extremely ill after exposures to even minute amounts of these substances.  Reactions can occur after chemicals are inhaled, ingested, or absorbed through the skin.  Chemically sensitive people also frequently react to foods, drugs, mold, pollen, and electromagnetic fields.

MCS Symptoms

The symptoms of MCS are diverse and unique to each person.  Symptoms range from mild to life-threatening and include, but are not limited to, headache, trouble concentrating, nausea, vomiting, diarrhea, fatigue, weakness, metallic taste in mouth, dizziness, numbness and tingling, wheezing, irregular heartbeat, joint and muscle pain, tremors, and seizures.  Altered brain chemistry may also cause anxiety, depression and emotional outbursts.  Symptoms in children include red cheeks and ears, dark circles under the eyes, hyperactivity, and behavior or learning problems. After an exposure, symptoms may occur immediately or be delayed by hours or days.  Reactions may last from a few minutes to weeks or months.

Who Gets MCS?

Many people who become chemically sensitive were once healthy individuals who tolerated chemical exposures like everyone else, until they had an exposure from which they did not recover.  For example, people have developed MCS after moving into a newly built house, having carpets installed in their office, or after having their home sprayed with pesticides.  Others slowly become ill over a period of years, seemingly as a result of the cumulative exposures of everyday life.

Reports from around the world indicate that chemical sensitivity is a global problem.  MCS occurs in people of all ages, races, and economic backgrounds.  It occurs twice as often in women as in men.  A national U.S. prevalence study found 11.2% of respondents reported a heightened sensitivity to common chemicals, and the numbers seem to be growing.

How is MCS Diagnosed?

A published consensus definition defines MCS as a chronic condition involving multiple organ systems in which low-level exposures to multiple chemically unrelated substances cause symptoms, and these symptoms improve or resolve when a person is no longer exposed to these substances.  

The key factor distinguishing MCS from other medical conditions is that MCS symptoms come and go, or wax and wane, in relation to levels of chemical exposures that do not ordinarily affect others.

People with MCS frequently have imbalances in their nervous, immune, and hormonal systems, as well as impaired detoxification abilities.  Some chemically sensitive people may appear normal, while others may appear quite ill.  A physical examination may reveal the presence of a rash, yellowish or pale skin, swollen hands or feet, wheezing, irregular heartbeat, trouble speaking and communicating, swollen lymph nodes, poor coordination, or tremors.  Lab tests that are frequently abnormal in people with MCS include SPECT brain scans, in-depth immune studies, and elevated levels of heavy metals or synthetic chemicals.

How is MCS Treated?

There is no known cure for MCS, but a variety of treatments can help people reduce their symptoms and improve their health.  The most helpful treatment is to avoid exposures to chemicals, foods, drugs, and electromagnetic fields that trigger symptoms.  A good place to start is to create a “safe” room in one’s home that is as free of triggering substances and conditions as possible.

Other treatments used to help people with MCS include nutritional supplements, digestive aids, hormone balancing, detoxification, desensitization, eliminating occult infections, oxygen, and immune stimulation.  Acupuncture, homeopathy, herbs, brain retraining programs and other alternative/complementary treatments have also helped some chemically sensitive people.  It should be noted, however, that people with MCS vary considerably in their response to treatments and their ability to tolerate them (with the exception of chemical avoidance, which is almost universally helpful).

Chemically sensitive people are advised to find a physician who is knowledgeable about MCS, in order to avoid getting sick in standard medical offices, being misdiagnosed, put through inappropriate or hazardous testing and treatment, and suffering from disbelief or even hostility from medical staff.  Many medical doctors who specialize in the evaluation and treatment of MCS can be located through the American Academy of Environmental Medicine, 316-684-5500, www.aaemonline.org.

Full recovery from MCS is rare.  Most people experience a chronic relapsing course with periods of improvement alternating with periods of setbacks.  Few people die from MCS, but deaths have been known to occur as the result of suicide, asthma, severe malnutrition and the inability to tolerate treatments for cancer, infections, and other serious illnesses.

Impact of MCS

People with mild to moderate chemical sensitivities may be able to make adjustments in their diets, home environment, type and location of work, clothing, and personal care products they use to remain productive and connected to the outside world.  At its worst, however, MCS is a severe, disabling, and isolating disease that forces people to alter every aspect of their lives.  People with severe MCS often lose their jobs, home, careers, family and friends.  They are unable to go into most buildings and some become homebound.  The isolation imposed by chemical barriers and lack of understanding of MCS contribute to the often devastating nature of this illness.

MCS Politics

The acceptance of MCS as a “real” illness by the medical community has been slow, and still has a long way to go.  This is largely the result of the extensive efforts of the chemical/pharmaceutical industry to prevent the recognition of MCS.  Manufacturers of pesticides, perfumes, carpets, scented cleaning products, paints, building materials and many other products could suffer large economic losses, resulting from lawsuits and diminished sales, if it became generally accepted that exposure to their products can make people sick.  They would rather silence the messenger than heed the message of chemically sensitive people that many consumer and building products are not safe.

Despite industry efforts, the validity of MCS continues to slowly gain ground.  MCS is recognized as a potentially disabling condition by the Social Security Administration, the U.S. Department of Housing and Urban Development, and an increasing number of other federal, state, and local government agencies.  People with MCS are covered under the Americans with Disabilities Act on a case-by-case basis, like all other people with disabilities.

MCS Future

People with MCS continue to organize locally, nationally, and internationally to educate others about this disease, promote research, advocate for those who suffer from it, and help prevent others from getting it.

Find specialists that will take your MCS seriously. Here are a couple places to start your contacts in the USA




A group of patients, scientists and doctors dedicated to understanding and helping those afflicted with MCS


Thank you to those that support the advancement of knowledge for MCS