Multiple Chemical Sensitivity
Historical Timeline



Multiple Chemical Sensitivity (MCS) has been around for a long time.  Here is a brief overview of the history.


Keywords:    chemical sensitivity, MCS, history



1925:  A biography is published about the French author Marcel Proust (1871-1922), revealing he probably had MCS.


1947(1):  The pesticide DDT is aggressively marketed.  A full-page ad in TIME magazine features a homemaker, farm animals and vegetables singing “DDT is good for me.”


1947(2):  Dr. Theron Randolph, an allergist in Chicago, realizes one of his patients is unusually reactive to low levels of chemicals.


1953:  Dr. Randolph sees a patient who gets sick when eating a commercial apple, but has no trouble with apples that are not treated with pesticides.


1962(1):  Dr. Randolph publishes the book Human Ecology and Susceptibility to the Chemical Environment.


1962(2):  Rachel Carson publishes her book Silent Spring, about the dangers from pesticides.


1963:  Three patients reliably identify food and water secretly stored in food-grade plastic containers or glass.


1965:  The Society of Clinical Ecology is formed as a medical society.  It is later renamed American Academy of Environmental Medicine.


1967:  The Human Ecology Study Group is formed as a patient support group in Chicago.


1969:  The Cuyahoga River in Cleveland is so polluted it catches fire.


1970:  President Nixon creates the U.S. Environmental Protection Agency (EPA).


1975:  Dr. William Rea opens the Environmental Health Center in Dallas, Texas.


1976(1):  Following the oil crisis and rising energy prices, new buildings are built to conserve energy with tighter construction, inoperable windows and centrally controlled ventilation systems.  The result is “sick building syndrome,” which becomes a buzzword a decade later. 


1976(2):  A factory near Seveso, Italy accidentally pollutes the area with dioxin.  It results in a massive cleanup and evacuation.  The European Community enacts industrial safety regulations as a direct response.


1977:  The Human Ecology Action League (HEAL) becomes the first national MCS patient organization in the United States.


1978(1):  Residents of the Love Canal neighborhood are evacuated.  Their houses were built on top of a toxic waste dump.  President Jimmy Carter declares a national emergency for the area.


1978(2):  A community for people with MCS is started near Wimberley, Texas.


1978(3):  Dr. William Rea is able to induce arrythmia in ten heart patients, by exposing them to foods, fumes or even tap water that they are sensitive to.


1979(1):  The U.S. National Institute for Occupational Safety and Health (NIOSH) sponsors a three-day symposium named “Mass Psychogenic Illness.”  All but one presenter promotes the idea that MCS is psychosomatic.


1979(2):  The U.S. Surgeon General states: “There is virtually no major chronic disease to which environmental factors do not contribute, directly or indirectly.”


1981:  The California Medical Association adopts the position that clinical ecology (treatment of MCS) is not a valid medical discipline.


1982:  The first MCS rental housing opens near Seagoville, Texas.  It mostly serves patients at Dr. Rea’s clinic.


1983:  The Los Angeles Times comic Strip Hello Carol makes fun of people with MCS.


1984:  Law AB3587 is passed by both houses in the California legislature, but is vetoed by governor Deukmejian after a lobbying effort.  It would have funded scientific research on MCS.


1984(2):  A study of forty houses in Tennessee by the U.S. Consumer Product Safety Commission found the indoor air up to ten times as polluted as outside.  They found between 20 and 150 different chemicals in each home.


1986:  The American Academy of Allergy and Immunology publishes a position paper opposing MCS.


1986:  California voters pass Proposition 65 (The Safe Drinking Water and Toxic Enforcement Act), which requires labelling of products that contain chemicals known to cause cancer, birth defects or reproductive harm.


1986(3):  Hundreds of workers in Silicon Valley chip factories become ill with MCS.  The manufacture of semiconductors involves many highly toxic chemicals.


1986(4):  Half of the six hundred workers in a new building at the University of Florida, Gainsville, complain about poor air quality.


1986(5):  Scientists expose 62 volunteers to a mixture of 22 common indoor air pollutants.  The volunteers had previously reported problems with indoor air.  They all had acute reactions to the mixture, but not to the blanks (placebo).


1986(6):  The U. S. Environmental Protection Agency bans lead for soldering water pipes.


1987:  Professor Mark Cullen publishes the book Workers with Multiple Chemical Sensitivities, which provides the first definition of MCS.


1988(1):  More than a hundred employees at the Environmental Protection Agency’s headquarters in Washington, D.C. are sickened when new carpeting is installed in a poorly ventilated building.  Indoor air quality problems are extensively covered by the press over the next five years.


1988(2):  The Environmental Protection Agency publishes a report on the air quality inside ten buildings, including four nursing homes, a hospital, a school and four office buildings.  They found up to 500 chemicals in the building air at concentrations up to a hundred times the outside air.


1988(3):  The EPA states in their guide to indoor air quality that ventilation guidelines are only “intended to satisfy 80 percent of a building’s occupants.”


1988(4):  The U.S. Social Security Administration adds a section about MCS to its manual for determining disability.


1988(5):  An MCS community is started in Snowflake, Arizona.


1988(6):  Major hospitals in the United States start restricting indoor smoking.


1988(7):  Smoking on domestic flights of two hours or less takes effect in the U.S.  The ban is gradually expanded to cover all flights.


1989:  A patron of the Bloomingdale’s department store in New York is involuntarily sprayed with perfume by a salesperson and ends up in the hospital for 11 days.


1989:  The tanker Exxon Valdez creates a massive oil spill in Alaska.  Several people hired to clean up the coast get sick with MCS from working with the harsh solvents.


1989:  A position statement from the America College of Physicians is dismissive of MCS.


1989:  Professors Nicholas Ashford and Claudia Miller produce a report on MCS for the New Jersey State Department of Health.  It wins the World Health Organization’s Macedo Award for Public Health.


1989:  Marin General Hospital in Marin County, California, opens a new five-story wing which was made less-toxic with input from the local MCS community.


1990(1):  Two dozen employees are made permanently sick with MCS after extensive pesticide spraying at a casino by Lake Tahoe, Nevada.


1990(2):  Eleven-year-old Kevin Ryan testifies before a U.S. Senate committee about the lawn-care pesticides that gave him MCS.


1990(3):  The Indoor Air Quality Act passes the U.S. Senate, but never gets through the U.S. House of Representatives.


1990(4):  The Department of Housing and Urban Development (a United States federal agency) recognizes MCS as a disability requiring “reasonable accommodation.”


1990(5):  The Americans with Disabilities Act is enacted.  It provides broad protection for disabled people against discrimination in employment and access to workplaces, public buildings, public places and public transportation.  The law’s broad definition of who qualifies clearly includes people with MCS, but attempts to get the courts to enforce the law prove extremely difficult.  Three people representing the MCS community were able to attend the White House signing ceremony.


1990(6):  The Chemical Manufacturers Association produces a briefing document for its members, where the consequences of an acceptance of MCS is spelled out.


1990(7):  The American Petroleum Institute and the Chemical Manufacturers Association convene a conference to discuss MCS.


1990(8):  The American College of Allergy and Immunology hold their annual conference in San Francisco.  One day is dedicated to discussing MCS, with all the scheduled speakers advancing the idea that MCS is purely psychological.  The conference is disrupted by demonstrators.


1990(9):  A chemical detector alarm went off in a part of the Seattle Children’s Hospital that stores hazardous chemicals.  There was no leak, the installation of new carpeting triggered the alarm.


1989-1997:  American Broadcasting Corporation (ABC) airs seven TV programs that are directly or indirectly critical of MCS.


1991(1):  More than ten thousand soldiers return from war with Gulf War Syndrome, which appears to be identical to MCS.


1991(2):  United Airlines refuse to let people with MCS board their planes on two different occasions.  Both passengers sue and win in court.


1991(3):  The two professors Nicholas Ashford and Claudia Miller publish the book Chemical Exposures: Low Levels and High Stakes.  (A second edition came out in 1998.)


1992(1):  Dr. Iris Bell proposes her Time-Dependent Sensitization hypothesis for MCS.


1992(2):  The city of Oakland, California drafts a policy to request people attending public meetings arrive fragrance free.  They gave up after being “hammered” by industry lobbyists.


1992(3):  California enacts a law protecting magazine subscribers against scented ads.


1992(4):  Major American magazines, including New Yorker, People and Harper’s Bazaar, stop perfumed ads or offer perfume-free versions.


1992(5):  The sixth season of the TV series L.A. Law features a character with MCS in one episode.


1992(6):  The fourth season of the TV series Northern Exposure features a character with MCS.


1993(1):  A clinic catering to people with MCS, AIDS, CFS and other controversial illnesses opens in Queretaro, Mexico.  It is operated by physicians who moved from the United States to avoid trouble with the medical boards.


1993(2):  The U.S. Supreme Court issues the Daubert rule which makes it harder to prove “toxic tort,” including MCS.


1993(3):  As airlines recycle more and more of the cabin air in order to save fuel, passengers start to complain.


1993(4):  A passenger was denied the use of a respirator on flights from Tel Aviv to Atlanta, via Zurich.


1994(1):  More than a hundred workers at Boeing in Seattle become sick with MCS when working with toxic chemicals.


1994(2):  A Washington State Medical Association official says MCS is “a belief, not a disease.  It’s a culturally acquired anxiety disorder, without known cause.”


1994(3):  Ten scientific articles published in the previous decade suggested MCS was purely psychological.  Several of them were frequently mentioned in the press.  A review by Davidoff and Fogarty concluded that “only one study reviewed . . . was judged to have fewer than eight methodologic problems . . .”


1994(4):  The American Lung Association, the Environmental Protection Agency, the U.S. Consumer Product Safety Commission and the American Medical Association jointly issue the document Indoor Air Pollution: An Introduction for Health Professionals, which recommends people offgas new carpets safely and speaks mildly supportive of MCS and Sick Building Syndrome.


1994(5):  The world’s first publicly funded MCS housing project, Ecology House, opens in San Rafael, California.


1995(1):  Film director Todd Haynes produces the movie Safe, which uses MCS to comment on the ongoing AIDS crisis and suburban dystopia.  Most reviewers interpret MCS as a psychological illness.


1995(2):  A survey of MCS patients and health providers is conducted across nine European countries.


1995(3):  The Environmental Sensitivities Research Institute (ESRI) is created to “support sound scientific and medical research into environmental intolerance issues, and to compile and disseminate information on those issues.”  It was widely considered an industry front created to discredit MCS.  It closed around 2008.


1995(4):  ESRI hires a public relations firm to place advertorials in newspapers across the United States.  They state that MCS “exists only because a patient believes it does and because a doctor validates that belief.”


1996(1):  American Broadcasting Corporation attempts to entrap Dr. Grace Ziem with fake patients posing as having MCS, but the attempt backfires.


1996(2):  The World Health Organization sponsors an invitation-only MCS conference in Berlin.  Anti-MCS forces strongly promote a new name, idiopathic environmental intolerance (IEI), to distance the illness from chemical causes.


1996(3):  A government-funded MCS and EHS apartment building is finished in Uppsala, Sweden.  It was poorly designed and never became a success.


1996(4):  Scientists at DePaul University asked 305 MCS patients about treatments they’ve tried.  Avoiding chemicals was rated best by far.  Psychiatric drugs, such as Prozac, Zoloft and Wellbutrin were rated the most harmful.


1996(5):  Dr. William Meggs and colleagues conduct a large MCS prevalence study on 1,027 people in North Carolina.


1996(6):  Professor William Morton proposes that MCS is linked to the illness porphyria.


1997(1):  Cindy Duehring is awarded the Right Livelihood Award for her MCS advocacy work.  She dies two years later from a pesticide exposure at the age of 35.


1997(2):  Professor Claudia Miller names her proposed explanation for MCS Toxicant-induced Loss of Tolerance (TILT).


1997(3):  The documentary Final Insult is produced in Australia, featuring four people with MCS.  The movie is shown to the MCS community but the public release is mysteriously delayed for eight months.  It is then displayed on Australian Broadcasting Corporation TV followed by a studio debate between three physicians and a “moderator,” whose bias against MCS is well known.  Only one person in the studio has sympathy for people with MCS.


1997(4):  Wall-mounted battery-powered fragrance emitters become the norm for public restrooms in the U.S.  Previously, milder fragrancing or none at all were common.


1998(1):  A group of workers were exposed to high levels of gasoline fumes while digging a tunnel through soil beneath a gas station.  A quarter of the workers became chemically sensitive.


1998(2):  The San Francisco Police Department adds a page about MCS to its Disability Awareness Guide.


1998(3):  The Governors of five American states issue proclamations in support of people with MCS.  More join in following years.


1999(1):  Dr. Richard Kreutzer and colleagues publish an MCS prevalence survey on 4,046 Californians.


1999(2):  A consensus criteria for diagnosing MCS is published by 34 physicians.  There are six criteria, based on symptoms.


2000(1):  Brigham and Women’s Hospital, a part of Harvard University in Boston, institutes a fragrance policy to improve their indoor air quality.


2000(2):  An issue of the Jehovah’s Witness magazine Awake! is dedicated to MCS.  The faith starts modifying some of their churches to accommodate people with MCS.


2000(3):  Halifax, Canada, becomes the first major city to restrict fragrances in public places.


2000(4):  The U. S. Centers for Disease Control and Prevention (CDC) issues a fact-sheet that states:  “Virtually all human diseases result from the interaction of genetic susceptibility factors and modifiable environmental factors...”


2005(5):  California passes The Healthy Schools Act, which encourages the use of non-toxic methods to combat bugs.  When pesticides have to be used parents and staff must be notified in advance and warning signs posted. 


2000(6):  The chemical manufacturer 3M stops producing the chemicals PFOS and PFOA because of health concerns.  For decades they were the main ingredient in 3M’s Scotchguard product that makes carpets, clothing and other fabrics stain repellent.


2001(1):  The World Trade Center in New York is destroyed by terrorists.  The toxic smoke from the burning buildings makes several people sick with MCS.


2001(2):  An assistant at a medical clinic comments on a patient’s powerful fragrance odor.  The patients assaults the assistant with her fragrance spray so the assistant collapses with anaphylactic shock and must be hospitalized.


2003(1):  British researchers find that use of household products with volatile chemicals is associated with infant earaches, diarrhea and vomiting.


2003(2):  A woman in Florida assaults her husband with fragrances and cleaning agents during a heated marital conflict.  Her husband has severe MCS.  The police charged her with aggravated battery.


2005(1):  A woman with MCS wore a respirator while visiting a shopping center in Queensland, Australia.  Someone thought she was a terrorist and called the police.  She had some difficulty convincing the police she was harmless.


2005(2):  Anonymous special interests attempt to revoke the licenses of Dr.’s William Rea and other environmental physicians, but have limited success.


2006:  The Danish government creates The Danish Research Centre for Chemical Sensitivities.  It was funded for eight years.


2007:  Professor Martin Pall proposes the NO/ONOO theory to explain both MCS and electrical sensitivities.


2008(1):  The United States Congress passes the ADA Amendments Act that strengthens the Americans with Disabilities Act from 1990.


2008(2):  Hurricane Katrina leaves thousands of families homeless.  They are housed in brand new “FEMA trailers” with high levels of formaldehyde.  Forty-two percent of the children in a study have respiratory problems.


2008:  A woman in Australia is forcefully committed to a mental hospital because of “Fixed belief that she is sensitive to chemicals and electromagnetic forces,” according to the paperwork.


2009(1):  Researchers from the U.S. Environmental Protection Agency tested the floors of 500 random homes.  They found residue of the pesticides chlordane (74%), DDT (42%) and heptachlor (13%) despite they have not been available for at least two decades, demonstrating how long-lived they are.  They do not say if they found any home without pesticides, but it seems unlikely, since just one pesticide, permethrin, was found in 89% of the homes.


2009(2):  The United States Centers for Disease Control and Prevention (CDC) issues a no-fragrance staff policy.  It deems fragrances “not appropriate for a professional work environment.”


2010:  Susan McBride wins lawsuit against the City of Detroit, which didn’t accommodate her inability to breathe in a fragranced office.


2011(1):  Copenhagen Airport creates a route so fragrance-sensitive passengers can bypass the perfume counters in the duty-free shopping area.  Vancouver and Helsinki follow a few years later.


2011(2):  A Danish study with 3460 people found that people with severe MCS also tended to have non-allergic skin reactions to chemicals.


2012:  An article by researchers at the King’s College Psychiatry Department claims that people with MCS just want to retreat from society and live like hermits.


2013(1):  Filmmaker Susan Abod releases the documentary movie Homesick.


2013(2):  An apartment building, specifically built for people with MCS and EHS, opens in Zurich, Switzerland.  It is organized as a cooperative with public and private donations.


2013(3):  The American College of Obstetricians and Gynecologists, together with the American Society of Reproductive Medicine, issue a statement suggesting that women who are pregnant, try to become pregnant or nursing a child, should eat healthy organic foods and limit their exposure to pesticides and other toxic chemicals. 


2014(1): The Danish supermarket chain Irma stops selling products containing fabric softener, chlorine or triclosan (Microban) because they are “unnecessary and damaging to the environment.”


2014(2):  The Canadian Community Health Survey finds that 2.7% of Canadians have MCS.


2014(3):  The Canadian Human Rights Commission issues Policy on Environmental Sensitivities in support of accommodating people with MCS.


2015(1):  A study from the University of Texas find that mothers with MCS are two to three times as likely to have a child with autism or attention deficit hyperactivity (ADHD).


2015(2):  German automaker Volkswagen, and later other automakers, are accused of cheating on emissions tests.


2015(3):  The American retailer Target publishes a list of hundreds of toxic chemicals it encourages vendors to eliminate from their products.


2016:  Walmart, the world’s largest retailer, follows Target’s lead by asking its vendors to remove eight chemicals from their products.


2017:  The documentary movie The Sensitives, directed by Drew Xanthopoulos, premieres at the Tribeca Film Festival.


2017(2):  A jury awards a California office worker $3 million because his supervisor refused to accommodate his MCS disability, and he was subjected to hostile acts such as finding his things soaked in perfume.  An appeals court upholds the verdict two years later.


2018(1):  A population study by professor Anne Steinemann shows the prevalence of MCS has doubled in a decade and it is easier for men to get a diagnosis than for women.


2018(2):  The streaming video service Netflix airs the seven-part “docuseries” Afflicted, about people with chronic and controversial illnesses, such as MCS.  It paints them as psychosomatic.


2018(3):  The U.S. Food and Drug Administration bans lead in hair dyes.


2018(4):  Australian scientists analyze 24 commercial essential oils and finds toxic chemicals in all of them, even those labelled “natural” or “organic.”  The most common chemicals are acetaldehyde and acetone, found in all, or nearly all, products.



More MCS history