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What is Multiple Chemical Sensitivity?
Quick Quiz : Are You Chemically Sensitive?
MCS Timeline - A Historical Perspective


Multiple Chemical Sensitivity (MCS) is an illness which is triggered by exposure to substances in the environment. Individuals with MCS have reactions to chemicals at concentrations that are far below what is tolerated by most people. Symptoms can occur in more than one organ system in the body, such as the nervous system, the lungs and the vascular system (heart problems). Exposures can come through the air, from food and water, or through the skin. As a person with MCS becomes more and more sensitive, their symptoms often become more severe and increasingly chronic, often affecting more bodily functions. No current medical test is currently available that can determine whether or not someone has MCS. So far, the most reliable test seems to be a quantitative EEG, but it is not widely available, it is expensive, and many doctors and insurance companies don't recognize its diagnostic capabilitites. The SPECT scan (done by a knowledgeable doctor) is also gaining some credence, although it cannot definately define MCS in any one person. It is estimated that about 15% of the population suffers from a form of MCS, although not everyone is disabled by it.

It doesn't seem to matter how you get MCS: an intense exposure to a toxic chemical, long-term exposure to low levels of toxins, or a genetic disposition to it. Once you get it, the pattern seems to be the same for most people. After a period of time, it takes lower and lower concentrations of trigger chemicals to provoke a reaction. Usually, an ever-increasing number of chemicals triggers reactions, a phenomenon known as "spreading."

No one knows why people get MCS. Many people claim to have the cure for it, but it is MY OPINION that once the body's ability to detoxify substances is compromised, it rarely bounces back. I have yet to meet anyone who has been "cured" of MCS; I have met people who have gotten better, but none who have returned to their former state of health. Most people cope with this by avoidance of chemicals (the majority of people I talk to are reactive to petroleum-based chemicals--more on this below--but it is possible to be sensitve to other substances, such as lime or chlorine). This means ridding your home of toxic carpeting, no more painting, no cars idling in attached garages, no more scented laundry detergents, and many other changes.

Many of the chemical triggers belong to a class of chemicals known as "volatile organic compounds" (VOC). These chemicals are usually derived from petroleum and readily evaporate into the air at room temperature. "Safe" airborne levels of these contaminants can make healthy people sick. Examples of VOCs include solvents, paint thinners, epoxy glue, and nail polish remover.

Both the US Department of Housing and Urban Development (HUD) and the Social Security Administration (SSA) have recognized MCS as a disabling condition, although it is very difficult to get a diagnosis from a physician. If your doctor gives you a hard time about MCS not being a "legitimate" illness, ask him/her to look at ICD codes #981 and all the sub-categories for that number, along with #987.x (there are numerous appropriate numbers here). This is an illness that is as valid as diabetes or leukemia, and it gets a number for billing just like those diseases.  With the unfortunate plight of the Gulf War veterans looming over the traditional medical system, there is hope that there will be more information available for physisicans and their collective consciousness will be raised.

(Many thanks go out to the Multiple Chemical Sensitivity in the Workplace Task Force, c/o NY Coalition for Alternatives to Pesticides, 33 Central Avenue Albany NY 12210 (518)426-8246, for providing the outline for this information)

QUICK QUIZ:  Are You Chemically Sensitive?

A "yes" answer to any of these questions may indicate that you have a heightened degree of chemical sensitivity and are at risk of developing Multiple Chemical Sensitivities (MCS), a potentially serious and disabling medical condition characterized by intolerance to almost everything in one's environment.

To prevent your sensitivities from worsening, it is important that you reduce or eliminate your exposure to chemical pesticides (including bug sprays, weed-killer, and moth balls), solvents, new carpets, and new or recently remodeled homes or offices. The use of unscented personal care products is also highly recommended.


After WWII

The economic revival after the Second World War leads to a huge increase in industrial production.  Industrial nations begin using man-made chemicals in many different commercial applications.  Nerve agents developed for use in warfare are reformulated to create effective pesticides.  Many everyday household products now contain chemicals to improve their effectiveness.  Synthetic fragrances are added because they “clean the air”, are easier to make and are inexpensive.  This is the start of the chemical soup that we encounter today.


Working at his office in Chicago, Dr Theron Randolph notes that several of his patients have a "petrochemical problem" in that they become ill when passing through the heavily industrialized areas of northwest Indiana and South Chicago.  These are the first known cases of MCS.


Dr. Theron Randolph's book “Human Ecology and Susceptibility to the Chemical Environment” is released. This is the first book of its kind to describe the medical condition which is now commonly referred to as MCS.

Rachel Carson's book “Silent Spring” shows that DDT and other chemicals being used to enhance agricultural productivity are poisoning our lakes, rivers, oceans, and most of all ourselves.  This landmark book helps set the stage for the environmental movement.


In response to the lack of acceptance within his specialty, Dr. Randolph founds the Society for Clinical Ecology and invites physicians of all specialties to take part.  In 1985, this Society changes its name to the American Academy of Environmental Medicine.


The Human Ecology Study Group (HESC) is formed as a support group for the patients of Dr. Randolph.  This is the first known MCS support group and is still in existence today.


In response to the energy crisis, traditional office buildings with windows are replaced by tight, energy-efficient buildings.  These new structures limit the amount of fresh air being circulated and lead to many cases of “Sick Building Syndrome”.


As the number of MCS cases grows, Drs. Randolph and Rea begin operating environmental control units to help identify chemicals and foods that provoke symptoms in MCS patients.


The Human Ecology Action League, Inc. (HEAL) is founded in 1977 by citizens concerned about the health effects of environmental exposure. This distinguished group of volunteers includes physicians, writers, and other professionals.


U.S. District Court in Hawaii rules that MCS can be disabling, and orders the Department of Health, Education, and Welfare Division to provide Social Security benefits to an MCS patient.


A California bill to require research on MCS is passed in both houses of state legislature, but is opposed by the California Medical Association.


Worker's Compensation awarded by Oregon court to a furniture store worker with MCS.


"Workers with Chemical Sensitivities" paper is published by Occupational Medicine Journal.  This paper provides one of the first working definitions of MCS.

Worker's Compensation awarded by California court for exposure to industrial chemicals.


Supplemental Security Income now covers MCS on a case by case basis.

Workers at the EPA headquarters become ill when new carpets are installed and some develop MCS.  It is the ultimate irony when a leading indoor air consultant calls EPA headquarters one of the sickest buildings in the nation.  As the number affected reaches over 30%, the EPA spends over $4 Million on health care costs, studies and renovations in an attempt to improve air quality.  However, a number of people are too ill to return to work.


Indoor Air Quality Act is amended to address MCS.

Ohio Court of Appeals finds unlawful employment discrimination of worker with MCS.

Because of HEAL's desire not to get involved with political issues, Mary Lamielle founds the National Center for Environmental Health Strategies (NCEHS).  The main interest of this group is to fight for the rights of those who are already environmentally ill.

Florida passes legislation creating a pesticide notification registry for persons claiming chemically related illness.  Most states eventually follow Florida’s lead.


The Americans with Disabilities Act (ADA) is signed into law, stating that no one can be discriminated against on the basis of disability and requiring that all disabilities are entitled to reasonable accommodations.  By definition this act covers people with MCS.

American Public Health Association states that MCS should not be labeled psychogenic unless environmental causes have been ruled out. 

Department of Housing and Development (HUD) recognizes MCS as a disability and the Department of Justice considers MCS to be a handicap.

The Chemical Injury Information Network (CIIN) is created.  Its main focus is on education, credible research on MCS, and the empowerment of the chemically injured.


The Agency for Toxic Substance and Diseases Registry provides support for two major national conferences on the subject of MCS. The first is held at the National Academy of Science Meeting and the second is sponsored by the Association of Occupational and Environmental Clinics.


Thousands of Persian Gulf veterans return from the war complaining of symptoms which are very similar to MCS.  These veterans were exposed to oil-well fires, paints, fuels, pesticides, solvents and other chemicals.  As the number of potential cases rises to about 80,000 or about 10% of the people deployed in the gulf, the VA claims that the majority of these people have symptoms that are stress related.

HUD recognizes MCS as a handicap entitled to "reasonable accommodation." 

U.S. Congress appropriates $250,000 for MCS research.

A major primetime TV series “Northern Exposure” introduces a new character who has chronic MCS and lives in an environmental dome in rural Alaska.


Mt. Sinai Occupational Health Clinic is awarded $100,000 for an MCS study.


Agency for Toxic Substance and Disease Registry publishes MCS study.

Cindy Duehring and Cynthia Wilson, CIIN's executive director present a paper entitled “The Human Consequences of the Chemical Problem”, to the Vice President, the First Lady, the National Institute of Health and the CDC.  The paper is peer reviewed and is found to have "merit" and a conference is convened to discuss the health issues raised by the paper.


A major movie “Safe” is released featuring Julianne Moore as a Southern Californian housewife who struggles to adjust to a chemically sensitive lifestyle.

The European Commission produces a report “Chemical Sensitivity in Selected European Countries: An Exploratory Study”.  This report suggests that MCS is a global phenomenon.


ABC broadcasts an episode of 20/20 entitled “Allergic To The World” in which reporter John Stossel depicts MCS as a psychiatric disorder.  Stossel calls MCS “junk science” and causes an outcry from clinical ecologists and MCS sufferers.


The states of CT, MO, NM, NC, VT, WA and Bradenton, FL declare "MCS Awareness” Weeks.


The state of Kentucky declares an MCS Awareness week.

A California study finds that 16% of people report being “allergic or unusually sensitive” to everyday chemicals and a New Mexico study confirms this number by reporting that 15.9% of a random sample is sensitive to chemicals.

Apr 2000

Nova Scotia bans the use of fragrances and chemical hair products in public places.  This is the first city to take direct action to accommodate their MCS community by improving air quality in this way.  This is a landmark victory for MCS sufferers everywhere.

Nov 2000

Germany puts MCS in its International Classification of Diseases, the first country to do so.  However, it is listed under the section entitled “allergy, not otherwise specified”.

Sept 2003

A study by HEAL member Stan Caress shows 12.6% of Georgians have a hypersensitivity to common chemicals.  This is consistent with previous studies.

Apr 2004

MCS is recognized, defined and described in the Merck manual.  This manual is heavily used by mainstream physicians and contains virtually all the disorders that might be encountered.

Oct 2004

US Scientists now claim that Gulf War Syndrome does exist.  This is a tremendous relief to the thousands of troops who were chemically injured in the Gulf War and who were told by the Veteran’s Administration that their illness was largely psychosomatic.

Nov 2004

A Minnesota woman is fired from her job at the Target Corporation, because she refuses not to wear her perfume.



Denmark, in response to an increasing number of MCS cases, plans a center for fragrance and chemical sensitivity.  With a grant of about a half million Dollars, this center is intended to help MCS become a well-defined and accepted illness.


New legislation requires European cosmetic fragrance manufacturers to list on their packaging 26 ingredients which are considered to cause allergic reactions.  Although manufactures regularly use up to 200 separate ingredients in a perfume, this is seen as an acceptable compromise.



CIIN convenes a national conference to discuss the major issues surrounding MCS and forms workgroups to tackle the most urgent problems.  These workgroups are MCS Case Definition, MCS Housing, Medical Education, MCS Registry and Religious Accommodation.

May 2005

Perfume Allergy Case Brings $10M Judgment.  A jury awards $10.6 million to one-time radio host who was fired after complaining a co-worker's perfume made her sick and her employer, Infinity Broadcasting, would not accommodate her.

 New York City adopts plan to curtail the use of Pesticides.


“Multiple Chemical Sensitivities (MCS): What It Is, What It Is Not." by Sheila Bastien (1995).
“Multiple Chemical Sensitivity – A Survival Guide” by Pamela Reed Gibson (1999).
“Our Toxic Times” – Monthly newsletter of Chemical Injury Information Network (2005).
Environmental Health Association of Nova Scotia” - David Steinman, (Fall 1993).

“Chemical Sensitivity in Selected European Countries”: An Exploratory Study (1995).
“The Merck Manual of Medical Information - Second Home Edition Online” (2003)
“Gulf War Syndrome Covered Up” – Covert Action Quarterly by Dennis Bernstein (Issue #53).

Note:  In an attempt to chronicle the history of MCS, significant events may have been omitted.  Please contact me at info@atlantaheal.org if you know of anything that should be included in this timeline.

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