Dear EarthTalk: What is “Multiple Chemical Sensitivity” and what causes it?

Dear EarthTalk: What is “Multiple Chemical Sensitivity” and what causes it?

— Sara Morris, Houston, TX

People suffering from otherwise unexplainable medical problems such as headaches, fatigue, shortness of breath, and even chest pains may have everyday chemicals to blame. Multiple Chemical Sensitivity (MCS) is a medical condition whereby such symptoms can be attributed to the combined exposure to synthetic pollutants commonly found in detergents, perfumes, pesticides, solvents and even some foods and medicines.

While MCS goes by many other names—including “Environmental Illness” and “Total Allergy Syndrome”—perhaps none captures the essence of its causes and effects quite as well as “20th Century Disease.” Between 1940 and 1980, the production of synthetic organic chemicals worldwide increased from less than 10 billion pounds per year to more than 350 billion. MCS has been called “an allergy to modern life,” literally a physical reaction to many of the common chemicals now widely distributed.

No longer rare, MCS reportedly affects 10 percent or more of Americans. Nevertheless, the medical community rarely takes the condition seriously. “Because MCS does not fit any of the three currently-accepted mechanisms of disease—infectious, immune system, or cancer—traditional medicine has not known how to explain MCS, and so has often labeled it “psychogenic”—originating in the patient’s mind,” writes Dr. Peter Montague in Rachel’s Environment and Health Weekly. “This has left MCS sufferers in limbo. Told they are crazy, or imagining their disease, or making it up, they find themselves passed from physician to physician without any satisfactory answers and often without relief from their very real distress.”

According to the federal Occupational Safety and Health Administration (OSHA), “There is insufficient scientific evidence to confirm a relationship between any of these possible causes and symptoms.” While OSHA does not verify the legitimacy of MCS, it does offer some relief by regulating the use of cleaning products and other air quality contaminants. But some of the most ubiquitous MCS offenders—perfumes and air fresheners—are not subject to testing for toxics, and as such remain unregulated.

“It”s oxymoronic to talk about perfumes and other fragrances that can be used by people with chemical sensitivities,” says Albert Donnay, director of Multiple Chemical Sensitivity Referral & Resources. In order for perfumes and air fresheners to give off a scent or be effective, he explains, they must contain volatile organic compounds (VOCs). Even “all-natural” products give off some VOCs. “People with chemical sensitivities have to give up wearing perfume products, and people that do wear perfume need to be sensitive to the needs of people with chemical sensitivities. It”s not much different than smoking, only you can see second hand smoke,” adds Donnay.

CONTACTS: Rachel’s Environment and Health Weekly, (888) 272-2435,; Occupational Safety & Health Administration (OSHA), (800) 321-6742,; Multiple Chemical Sensitivity Referral & Resources, (410) 889-6666,