Use the interactive map to learn how MCS prevalence varies by province and territory.
***Prevalence statistics for Nunavut, Northwest Territories, and Yukon are derived from the 2015-2016 CCHS due to data collection constraints MAP: ASEQ-EHAQ* Source Statistics Canada, 2015-2016 and 2020 Canadian Community Health Survey (CCHS)
Multiple Chemical Sensitivity (MCS) is a chronic health condition and a recognized disability nationally and internationally. It is triggered by exposure to volatile organic compounds (VOCs) and other chemicals found in fragrances and other conventional products, including personal care products, cleaning and laundry products, , air fresheners, ), and chemicals emitted from building materials and furnishings.
Due to sensitization from exposures, MCS can affect multiple body systems and make it difficult to access spaces essential for everyday living, such as workplaces, healthcare settings, schools, and public places.
For people living with Multiple Chemical Sensitivity (MCS), exposure to triggering substances reliably results in reactions. While the specific triggers may differ, continued exposure can increase sensitization and broaden the range of substances that cause harm.
● Heightened sense of smell
● Migraines / headaches
● Dizziness / vertigo
● Brain fog (feeling “spacey”), difficulty concentrating
● Memory challenges
● Insomnia / sleep disruption
● Fatigue / exhaustion
● Coughing / wheezing
● Shortness of breath (asthma-like symptoms)
● Chest symptoms
● Sinus pain / sinus infections
● Sore throat
● Swollen glands
● Flu-like symptoms
● Coughing / wheezing
● Shortness of breath (asthma-like symptoms)
● Chest symptoms
● Sinus pain / sinus infections
● Sore throat
● Swollen glands
● Flu-like symptoms
● Coughing / wheezing
● Shortness of breath (asthma-like symptoms)
● Chest symptoms
● Sinus pain / sinus infections
● Sore throat
● Swollen glands
● Flu-like symptoms
● Coughing / wheezing
● Shortness of breath (asthma-like symptoms)
● Chest symptoms
● Sinus pain / sinus infections
● Sore throat
● Swollen glands
● Flu-like symptoms
Hear directly from people living with Multiple Chemical Sensitivity (MCS) across Canada as they share their stories, challenges, and daily realities. These lived experiences from different provinces help build awareness, understanding, and compassion.
Multiple Chemical Sensitivity (MCS) can profoundly change family life. When one or more family members live with MCS, daily routines, relationships, housing choices, schooling, work, and access to healthcare can all be affected. Families often find themselves adapting without clear guidance, consistent support, or a shared understanding of what appropriate care and accommodation should look like.
Many families also encounter pushback, disbelief, and isolation as they advocate for safer environments and basic access.
If your family is living with MCS, you are not alone. We recognize the realities you face, honour your endurance, and are here to listen, support, and help you find a way forward.
Multiple Chemical Sensitivity (MCS) creates significant barriers to accessing everyday environments. Chemical exposures in offices, schools, healthcare settings, and public spaces routinely limit participation when accommodations are not in place. In the absence of accessible environments, exclusion can be severe.
MCS also has a measurable impact on employment. In Canada, more than 41% of people living with MCS are not working, compared to approximately 26% of the general population. Similar patterns are observed in Québec
Ability to enter workplaces, maintain employmentb, or participate in meetings
Finding or maintaining a healthy, lowest volatile organic compound (VOC) emissions, least toxic, and fragrance-free living environment
Difficulty accessing clinics, appointments, and hospital settings
Barriers in school environments, events, and community spaces
Misunderstanding and stigma that can lead to social isolation
Increased costs associated with creating safer environments and managing daily needs
Multiple Chemical Sensitivity (MCS) can be life-changing, and day-to-day management often depends on the choices and actions of people, systems, and environments around the person affected.
Appropriate support can reduce barriers and improve access, while lack of recognition, disbelief, or misdiagnosis can contribute to isolation, loss of income, and financial strain.
People living with MCS require recognition of their access needs, appropriate care, and effective accommodations — particularly within families and close support networks. Simple, practical steps, such as adopting fragrance-free practices and removing triggering products, can make a meaningful difference in daily life and well-being.
There is no single laboratory test that definitively diagnoses Multiple Chemical Sensitivity (MCS). Diagnosis is based on clinical assessment, including medical and exposure history, physical examination, and appropriate investigations to rule out other conditions.
Internationally recognized guidance exists. The 1999 Consensus Statement outlines core characteristics of MCS, and validated screening tools such as the BREESI and QEESI are used to support clinical assessment and case identification.

Repeated exposure triggers consistent symptoms

Symptoms persist over time

Reactions occur at minimal exposure levels

Symptoms reduce when exposure stops

Unrelated chemicals trigger symptoms

Neurological, respiratory, immune systems involved
Despite this, many healthcare providers receive little or no training on MCS. As a result, the condition is often missed, misunderstood, or misdiagnosed, delaying recognition, care, and access to accommodations.
In Québec, there is no dedicated clinical centre for MCS, and hospital environments are often not equipped to safely receive highly chemically sensitive individuals. An environmental health clinic in Toronto provides diagnostic services and clinical support, but comparable services remain limited across much of Canada.
Multiple Chemical Sensitivity (MCS) creates significant barriers to accessing everyday environments. Chemical exposures in offices, schools, healthcare settings, and public spaces routinely limit participation when accommodations are not in place. In the absence of accessible environments, exclusion can be severe.
MCS also has a measurable impact on employment. In Canada, more than 41% of people living with MCS are not working, compared to approximately 26% of the general population. Similar patterns are observed in Québec
Across home, work, school, healthcare, and public spaces.
Through fragrance-free and least toxic product choices
That protect energy, support stability, and reduce cumulative exposure
Multiple Chemical Sensitivity (MCS) is a nationally and internationally recognized medical condition and disability. In Canada, MCS is recognized within human rights frameworks, including guidance from the Canadian Human Rights Commission, which affirms the right to reasonable accommodation for disability-related access needs.
Internationally, the UN Committee on the Rights of Persons with Disabilities, in its Concluding Observations to Canada, has explicitly referenced Multiple Chemical Sensitivity, affirming that people living with MCS are entitled to equal access, reasonable accommodation, and protection from discrimination under the UN Convention on the Rights of Persons with Disabilities.
Medical recognition has also advanced. In 2025, the American Medical Association adopted policy recognizing fragrance sensitivity (including Multiple Chemical Sensitivity) as a condition that can substantially limit major life activities and supporting fragrance-free environments and accommodation.
Reasonable accommodations for people with MCS may include fragrance-free practices, reducing chemical and off-gassing exposures, advance notice of cleaning or renovations, improved ventilation, flexible work arrangements (including remote options), and adjustments to seating or work location.
Requests for accommodation are rights-based, not special treatment. When environments are accessible, barriers are reduced, participation is enabled, and stigma and conflict are less likely to occur.
ASEQ-EHAQ supports people with MCS and their families through resources, information, education, advocacy, and awareness. If you need help, contact ASEQ-EHAQ.