Multiple chemical sensitivity (MCS)

Scope

Multiple chemical sensitivity may affect a small percentage of the population, and is not currently recognized by the major medical organizations. Medical opinion is divided, however, and further research is needed.

Proposed theories to explain the cause of MCS include allergy, dysfunction of the immune system, neurobiological sensitization, and various psychological theories. There is insufficient scientific evidence to confirm a relationship between any of these possible causes and symptoms. Due to the lack of definite information an evaluation must be performed by a physician knowledgeable of the symptoms of this condition.

Regulatory citations

• General Duty Clause — OSH Act of 1970

Key definitions

• Allergy: A reaction of the immune system to various substances.
• Multiple chemical sensitivity (MCS): A condition in which a person is considered to be sensitive to a number of chemicals at very low concentrations.

Summary of requirements

Symptoms of MCS involve more than one organ and are brought on by exposure to very low levels of chemicals. No physical signs can be found consistently in MCS patients. Some symptoms include fatigue, loss of concentration, depression, and joint and muscle pain. Sources of chemicals that are believed may bring on the effects include pesticides, paints, adhesives, carpets and carpet cleaning materials, fragrances in perfumes and personal hygiene products, molds and fungi, petroleum products, electromagnetic fields, dental fillings, trauma, and industrial chemicals. Odors are often said to trigger the effects.

Employers should:

• Recognize and respond to employees complaining about symptoms that seem to originate from airborne substances.
• Accommodate the complainant and work with them to help alleviate the symptoms.