What is Multiple Chemical Sensitivity (MCS)?
Solutions and Prevention


When it comes to chemicals in the environment, there isn’t as clear a division between outside and inside as you may think. Where we live, work, and spend time is always connected to the land, air, and water. Our windows open, houses and buildings breathe and have air intake and emissions vents, we flush chemicals down drains, sinks and pipes into water systems, and the waste from the products we use is emitted to the air during their use, and goes to landfills. It is important for everyone to be able to access clean air, clean water and clean food. It is also important for everyone to keep the air, water, and food healthy and safe for future generations.

One of the best ways to prevent multiple chemical sensitivity (MCS) is avoidance of chemical exposures and the use of scent/fragrance-free, and less toxic products. Research has shown that improving air quality is an important intervention to help support those living with MCS and make spaces more accessible. Communities of individuals living with the disability MCS report that they have less barriers if they have accessible air.

Another way of thinking about the issue of exposure prevention is through the metaphor of “here” and “away.” Chemicals are here. They do not easily go away, even though we may imagine them to. The diffusion, or dispersal, of chemicals, scents and fragrances is not enough. Letting odours and chemicals disperse lets inaccessible spaces continue to exist. We need to do more to address the problem of air pollution, and the potentially harmful and disabling effects of chemicals. Who are always living in others’ “away” of chemicals, the place where chemicals are always “here”? People living with MCS.

A quote from an anthropologist who studies toxicity and disability, Dr. Zoë Wool, is useful to discuss the issue of “here” and “away” further.

Diffusion Is Movement, Away Is Not Escape

“Here” is what linguists call a deictic; it only makes sense if you know the situation, the where and the when. “Away” is something else, defined by the condition of being elsewhere. But whose elsewhere? Whose here makes my here (or your here, or their here) an elsewhere? What geographies and histories converge in such place-making? In making such situations? In situating some of us in a here, and others in an away? In putting us in our places? Here and away are always part of the same situation—a situation of legibility that attempts to make elsewheres and otherwises disappear, no matter how much is displaced from here to there, accumulating in landfills and aquifers, no matter how many bad smells and body burdens build up. Despite the early twentieth-century sense that diffusion was the solution to pollution, diffusion is movement, not escape… Here and away—but away is somebody else’s here.”

Your away may be someone living with MCS here. For this reason, preventative measures for environmental health are especially important for managing MCS.

Indoor air quality is significantly impacted by the consumer products we use. To support your health, those living with MCS and other disabilities impacted by air quality, and the health of the planet, choose products with the least possible toxins for personal use, cleaning and maintenance. Research clearly demonstrates a strong link between air pollution and human health, and further research is underway. Overall, prevention is key to supporting accessibility and wellness in the long-term. We need prevention now, and for future generations.

Other tips for improving air quality and environmental health in your living environment include:

  • Monitor humidity levels and ensure that there is adequate ventilation in order to decrease indoor air pollution, and prevent mold growth. Use a water purification system. Studies have shown that several human-made products including pharmaceuticals are showing up in tap water.
  • Avoid storing your water and food in plastic containers. Glass, ceramic and stainless-steel containers are safer alternatives.
  • Eat organic food. Organic food, and food free of pesticides is one of the best investments for your health. One option is to try freezing organic farm vegetables in the summer which can last through the winter.
  • Use an indoor air filter with a HEPA to reduce both particulate matter pollution (from sources such as smoke, dust, allergens, and mould), and an activated charcoal layer to reduce gas-based pollutants such as VOCs

Our partner, the Environmental Health Association of Quebec, has built a complete guide for healthier use of consumer products. This tool will help you implement safer and more accessible product use at all levels of your daily life. You can find the complete guide here.

You can also find more information about solutions and prevention in the workplace, at home, and through legislative action in our Resources section (in the menu on top of the page).

Getting a diagnosis

Getting a diagnosis is necessary to support, correctly assess, and treat the symptoms caused by MCS. However, due to the stigma surrounding MCS and the challenges communicating with medical personnel, getting correctly diagnosed can be difficult. Medical practitioners may feel overwhelmed and underqualified to assess and diagnose MCS, however, this doesn’t have to be the case.

Here, we provide tools that you can share with your doctor or healthcare provider. These tools can show them best practices in understanding and supporting MCS. Individuals don’t need to spend years seeking a diagnosis when medical professionals themselves feel educated, prepared, and supported in regard to environmental health.

You can ask your healthcare provider to keep a record of your recent exposures and symptoms in order to help identify existing sources of exposure and possible areas for intervention in your home, workplace, and everyday spaces. Below under the “Activity and Symptoms Record link” you will find a template that can help keep track of these exposures.

Another useful tool that can support the diagnostic process is to take a detailed Lifetime Exposure History. This questionnaire goes through your daily habits, the products you frequently use and the symptoms you might be experiencing to get an overview of the total load of exposures your body may be processing.

Lastly, to quickly self-assess if you may have MCS or scent/fragrance sensitivity, you can take the Quick Environmental Exposure and Sensitivity Inventory linked below.

To get your Activity and Symptoms Record, click here.

To view the Exposure History log, click here.

To take the Quick Environmental Exposure and Sensitivity Inventory (QEESI), click here.


In order to receive proper treatment, individuals with MCS require accessible medical care. Accessing medical care for people with MCS can involve many barriers if necessary accommodations and fragrance-free environments are not implemented in healthcare institutions and by medical staff.

Below are tools that support the creation of safe and accessible environments for people with scent/fragrance sensitivity and MCS.

Medical staff can view this report from the Canadian Society for Environmental Medicine:

Part one of the Canadian Society for Environmental Medicine’s report.

Part two of the Canadian Society for Environmental Medicine’s report

Here is a backgrounder which discusses disability for healthcare providers more broadly.

As an individual with MCS, you can visit our partner’s (ASEQ-EHAQ) website to learn more about making healthcare in Canada fragrance-free. You can also download more tips sheets and supporting documents on their website.

Please also visit the Canadian Centre for Occupational Health and Safety’s website for information about implementing a fragrance-free policy in your health-care establishment.

For more information on scent-free buildings, you can view the report of the Canadian Committee on Indoor Air Quality and Buildings. This document provides building owners and managers with important knowledge about the sources and effects of scents and fragrances.