Prevalence & Recognition
The number of people diagnosed with Multiple Chemical Sensitivity (MCS) in Canada — 940,500 in 2015, 1,008,400 in 2016, and 1,130,800 in 2020, showing a consistent increase over time. Data sourced from the Canadian Community Health Survey (CCHS), 2015, 2016, and 2020.
The chart highlights the large gap between individuals who self-report chemical sensitivity and those who receive a formal diagnosis. Globally, an estimated 9–16% of people report some level of sensitivity, while only 0.5–4% are formally diagnosed with Multiple Chemical Sensitivity (MCS). This difference suggests that many affected individuals remain undiagnosed or under-recognized within the healthcare system. Data sourced from the Canadian Community Health Survey (CCHS) 2020
Many people around the world report being sensitive to chemicals, with an estimated 9–16% of the global population experiencing some level of reaction to them. However, only a small number—around 0.5–4%—receive a formal diagnosis of Multiple Chemical Sensitivity (MCS).
In Canada, about 3.52% of the population has been diagnosed with MCS. The number of diagnosed cases has risen sharply, increasing by 200–300% over the past decade. In 2020, this meant that roughly 1.13 million Canadians were living with a confirmed diagnosis of MCS.