Home Articles Resources Archives Mailing Lists Classifieds


Introduction to Multiple Chemical Sensitivities

by Cyndi Norwitz
May 2003

This page can be sponsored by your company

Multiple Chemical Sensitivities (MCS) is a syndrome with the major presenting symptom of marked reactions to a variety of toxins in concentrations that most healthy people can tolerate. MCS overlaps substantially with Chronic Fatigue Syndrome (presenting symptom is fatigue) and Fibromyalgia (presenting symptom is pain) to the point that many consider them to be variants of the same disease. Gulf War Syndrome is also most likely MCS or something very similar.

The sensitivities of MCS are similar to allergies but, for most, do not qualify as allergies in the strict sense of a process leading to a specific set of bodily responses within approximately 20 minutes. The resulting symptoms include those of traditional allergies, such as headaches, migraines, nausea, anaphylactic shock, asthma, rashes and other skin eruptions, as well as more unusual symptoms such as acute abdominal pain, fatigue, insomnia, neurological signs, brain fog (a cloudy feeling in the head connected to loss of memory, cognitive functioning, alertness, and mental sharpness), body aches and pains, and, rarely, heart attacks.

Toxins that trigger MCS attacks can come from a variety of sources. Many people with MCS react to traditional allergens such as foods, dust, air pollution, pollen, animal dander, and molds, but the most common toxins that cause reactions are chemical substances found in everyday life. Perfumes, air fresheners, cigarette smoke, dry-erase markers, many household cleaning products, fabric softeners and dryer sheets, scented detergents and other products, new carpeting, solvents, fresh tar, and pesticides are among the most common reactants but do not make a complete list.

Although there are congenital cases, most people with MCS acquire it as an adult. The body loses the ability to process toxic substances. Many people with MCS end up so sensitive to some chemicals that they can react to amounts so small that a healthy person might not even know it is there. This is especially true in people whose bodies are overloaded with past chemical exposures (toxins that never break down and exit the body).

Anyone can acquire MCS; most sufferers had normal healthy lives before becoming ill. The most common way of acquiring MCS is chemical injury. One very large chemical exposure or many smaller exposures over time can lead to the body losing its ability to detox. Exposure to pesticides is a frequent route to MCS. Once the body's ability to process toxins is damaged, the person will react to chemicals he or she never had trouble with before, including chemicals not involved in the original injury.

Chemical injury is not the only way to impair the detox processes. Some other routes to MCS include viruses, severe emotional or physical trauma (especially in childhood), liver damage, or disorders of metabolism. Some people with MCS also have porphyria, a genetic disorder of the enzyme pathways that may not manifest itself until triggered by a chemical exposure.


The most important treatment for MCS is complete avoidance of toxins that cause the person to react. Unlike with some allergies, there is no way to medicate the reaction and allow the person full exposure to the substance. It is also important to avoid chemicals that may be further injuring the body even though the person is not obviously reacting to them.

Cleaning up the Local Environment: A Basic Checklist of the Most Common Reactants

Most people with MCS who get better do so through avoidance and careful, controlled detox of existing toxins in the body. Some detox can be done on one's own but it's best to start off with medical supervision. Some examples of detox methods are sauna, vitamin C, bentonite clay, charcoal, and special diets.

Some people with MCS can safely use medicines to alleviate symptoms but most people with MCS are also hypersensitive to drugs. Some people find lasting relief through mainstream treatments such as allergy shots. Others go outside of Western Medicine and successfully use Chinese Medicine (acupuncture and herbs). Chiropractic care, homeopathy, and massage can also be useful. Patients may wish to consider removing mercury amalgam dental fillings or silicon implants.

Links to Other Sources of Information

Immune Web

The author's site. Articles and links on many subjects related to MCS and similar conditions. Internet support groups, free classified ads

Multiple Chemical Sensitivity Referral & Resources

Non-profit organization with factsheets, scientific references, information on legal/government acceptance of MCS, and porphyria and carbon monoxide testing protocols.

Fragranced Products Information Network

Betty Bridges' detailed articles and references on the chemistry of MCS and perfume.

Environmental Health Network

Publisher of the New Reactor. Links to everywhere and much information on MCS activism.

This article is copyrighted. No reprints without permission

Home Articles Resources Archives Mailing Lists Classifieds

Cyndi Norwitz / webmaster@immuneweb.org / Last Modified: 5/10/03