Multiple Chemical Sensitivity

What you need to know

Multiple chemical sensitivity (MCS) is a chronic condition often referred to as environmental illness, total allergy syndrome, sick building syndrome, chemical intolerance, or idiopathic environmental intolerance.

Reported symptoms of MCS include migraine headaches, asthma, dizziness, difficulty breathing, skin problems, red or watery eyes, swollen lymph nodes, nausea, fast or irregular heartbeat, and muscle or joint pain.  MCS symptoms are reported to occur following exposure to concentrations of chemicals that are below the levels that are typically considered harmful for the general population (where the general population includes individuals who may be sensitive to chemicals, such as individuals with asthma).

The evidence that MCS is a medical disorder with established cause and effect relationships between symptoms and low-level chemical exposures is inconclusive. MCS has been described as a subjective illness marked by recurrent, nonspecific symptoms that occur in the absence of consistent objective diagnostic findings.

Given currently insufficient evidence to establish a causal relationship between any specific level of exposure and MCS symptoms, DPH recommends that individuals who have any symptoms seek the advice of a health care provider knowledgeable regarding the specific symptoms.

Additional Resources

American Academy of Allergy, Asthma and Immunology

American Academy of Family Physicians

American College of Occupational and Environmental Medicine

Occupational Safety and Health Administration

Quebec National Institute of Public Health

References

Black, DW and S Temple. 2021. Idiopathic environmental intolerance (multiple chemical sensitivity). UpToDate. https://www.uptodate.com/contents/idiopathic-environmental-intolerance-multiple-chemical-sensitivity

Jarry, J. 2021. Zeroing in on the Cause of Multiple Chemical Sensitivity. McGill Office for Science and Society. https://www.mcgill.ca/oss/article/health/zeroing-cause-multiple-chemical-sensitivity

Johns Hopkins Medicine. 2022. Multiple Chemical Sensitivity. https://www.hopkinsmedicine.org/health/conditions-and-diseases/multiple-chemical-sensitivity

Magill, MK and A Suruda. (1998). Multiple chemical sensitivity syndrome. American family physician, 58(3), 721.

Roof, KA. (2017). Multiple Chemical Sensitivity.  Encyclopedia of Clinical Neuropsychology. 2291-2295.

Rossi, S., and A Pitidis. (2018). Multiple chemical sensitivity: review of the state of the art in epidemiology, diagnosis, and future perspectives. Journal of occupational and environmental medicine.  60(2):138.