Multiple Chemical Sensitivity is a condition defined by the Environmental Protection Agency as “a diagnostic label for people who suffer multi-system illnesses as a result of contact with, or proximity to, a variety of airborne agents and other substances.”
MCS is the inability to tolerate an environmental chemical or class of foreign chemicals. It develops from exposure to substances in the environment such as toxic mold and pesticides, and may result in intolerance to even very low-level exposure to chemicals. Symptoms often occur in multiple organ systems such as the nervous system, the lungs, and the digestive system.
MCS has also been termed toxic injury (TI), chemical sensitivity (CS), chemical injury syndrome (CI), 20th century syndrome, environmental illness (EI), environmental intolerance (IEI), and toxicant-induced loss of tolerance (TILT).