COVID-19 and Multiple Chemical Sensitivity

How pandemic health measures affected Canadians living with MCS — and what the research tells us about safer practices going forward.
119Canadian adults with MCS surveyed
86%Reported increased disinfectant exposure
39%Were unemployed at time of study
Read the Research
Safer Cleaning Practices
Background

When Pandemic Measures Conflicted with MCS

The COVID-19 pandemic brought a dramatic increase in the use of cleaning products, disinfectants, and sanitizers across homes, workplaces, and public settings. For most people, these measures represented safety. For people living with Multiple Chemical Sensitivity (MCS), they represented a significant new source of chemical exposure.
Disinfectants, sanitizers, and cleaning products — many with strong fragrances and reactive chemical ingredients — are common MCS triggers. As these products saturated everyday environments during the pandemic, people with MCS faced a difficult reality: the public health measures designed to keep them safe were simultaneously making their condition worse.
ASEQ-EHAQ, in collaboration with researchers at Women’s College Hospital and the University of Ottawa, conducted a cross-sectional study and a qualitative study to document the lived experience of Canadians with MCS during the first year of the pandemic.

Key finding: During the first year of the COVID-19 pandemic, people with MCS experienced increased disinfectant exposure in their living environments, reduced access to healthcare, and greater social isolation — while also reporting some unexpected benefits including reduced stigma around wearing personal protective equipment.

Peer-Reviewed Research
JMIR Formative Research, 2024

The Impact of COVID-19 Health Measures on Adults with Multiple Chemical Sensitivity

A cross-sectional study of 119 Canadian adults with MCS documented how pandemic-related health measures changed their daily living environment, access to healthcare, and social support.
Participants compared their experience before and after March 11, 2020 across three domains: environmental chemical exposures, healthcare access and satisfaction, and social network contact.
Bray R, Wang Y, Argiropoulos N, Robins S, Molot J, Pigeon MA, Gaudet M, Auger P, Bélanger E, Peris R. JMIR Form Res. 2024 Jul 17;8:e48434. doi: 10.2196/48434.
Read the Full Study
119Canadians with MCS for more than one year completed the questionnaire
86.6%Were women; 57.1% had a university degree; 57.1% were over 55 years old
p<.001Statistically significant increase in exposure to disinfectants in home environments
p=.04Significant decrease in satisfaction with in-person physician visits
Key Findings

What Changed During the Pandemic

The study found both negative and unexpected positive changes in the experience of people living with MCS during the first year of the pandemic.

Increased Disinfectant Exposure

Participants reported a statistically significant increase in exposure to odors from disinfectants and sanitizers entering their living environments.

Increased ↑

Reduced Traffic Pollution

Perceived exposure to pollution from highways, roads, and industrial sources decreased significantly — one of the few exposure improvements reported.

Decreased ↓

Reduced Healthcare Access

Satisfaction with in-person physician visits decreased significantly. Telephone and online visits showed no significant change.

Decreased ↓

Increased Social Isolation

People with MCS experienced increased social isolation during the pandemic — compounding the isolation many already experienced in everyday life.

Increased ↑

Greater Family Understanding

A significant increase in understanding from family members was reported — as families spent more time at home and observed real-time effects of products.

Improved ↑

Reduced PPE Stigma

Decreased stigma around wearing personal protective equipment — masking became normalized, reducing judgment people with MCS faced in public settings.

Improved ↑
Healthcare Access

Barriers to Care During the Pandemic

The pandemic created new barriers for people with MCS seeking healthcare, while also revealing that remote care models could partially address pre-existing access barriers.

In-Person Care Challenges

  • Increased disinfectant use in clinical settings, triggering MCS reactions during visits
  • Higher anxiety around entering healthcare environments with heightened cleaning protocols
  • Reduced availability of family doctor access noted during the pandemic period
  • Significant decrease in satisfaction with in-person physician meetings (p=.04)

    • Remote Care: A Partial Solution

    No significant difference was found between pre-pandemic and pandemic satisfaction levels for telephone and online physician visits. This suggests that for some people with MCS, remote care may reduce exposure-related access barriers — even outside of pandemic conditions.

    National CCHS data show that people with MCS are three times more likely to report poor health and face significantly greater barriers to care, including service unavailability and difficulty accessing specialist services.

    Healthcare Provider Resources →
    Social Impact

    Isolation and Understanding

    People with MCS already face elevated rates of social isolation due to the pervasive presence of chemical triggers in shared environments. The pandemic amplified this — while also producing one unexpected shift.

    Social isolation increased significantly (p<.001) among people with MCS during the first year of the pandemic — compounding an already significant burden. For many, public spaces, workplaces, and social gatherings had already been inaccessible due to chemical exposures.

    It is important to understand that social isolation among people with MCS is a consequence of living with a disabling condition in an inaccessible environment — not a cause of MCS. Reducing isolation requires creating accessible spaces, not treating social withdrawal as a symptom to address independently.

    Family Understanding ↑

    Significant increase in understanding from family members (p=.03) as families spent more time at home together.

    PPE Stigma ↓

    Decreased stigma around wearing PPE (p<.001). Masking became normalized, reducing judgment people with MCS previously faced.

    Practical Guidance

    Safer Cleaning Practices for People with MCS

    Not all cleaning and disinfection approaches carry the same risk for people with MCS. Understanding the difference — and which ingredients to use and avoid — is essential.

    Cleaning with Soap & Water

  • Removes viral load to safe levels at home
  • Microfibre cloths remove up to 99% of viruses
  • Use fragrance-free soap
  • Required before sanitizing or disinfecting
    • Lowest-risk option

    Safer Disinfectant Ingredients

  • Alcohol — ethanol or isopropyl Safer
  • Hydrogen peroxide Safer
  • L-Lactic acid Safer
  • Citric acid Safer

    • Ingredients to Avoid

  • Bleach / sodium hypochlorite Avoid
  • Quats (quaternary ammonia) Avoid
  • Peracetic acid Avoid
  • Fragrances — add no cleaning benefit Avoid

    • Masking Safely with MCS

  • Wash new cloth masks twice before wearing
  • Use fragrance-free laundry products
  • Air out medical masks at least one week before use
  • Avoid scented soap or fabric softener

    • How Long Do Viruses Last on Surfaces?

    Surface typeApproximate durationMCS consideration
    Air, paper, tissue paperUp to 3 hoursGood ventilation reduces both viral load and chemical residue
    Cardboard, copper3–5 hoursSoap and water cleaning is sufficient for home mail and packages
    Wood, cloth1–2 daysFragrance-free soap removes viral load without chemical triggers
    Glass, stainless steel, plastic4+ daysAlcohol-based cleaning (≥60%) appropriate; avoid quats and bleach
    Resources

    Download the Research and Guidance

    Research Poster

    The Impact of COVID-19 Health Measures on the Quality of Life of Adults with MCS

    JASP 2023 conference poster presenting the cross-sectional study findings with key statistics and conclusions.

    Download PDF
    Fact Sheet

    Safer Cleaning Practices to Reduce COVID-19 and Virus Spread

    Practical guide covering cleaning vs. disinfecting, safer ingredients, products to avoid, masking guidance, and decision tree.

    Download PDF
    Health Canada Resource

    List of Disinfectants and Sanitizers Authorized by Health Canada

    Authorized hard-surface disinfectants and hand sanitizers, plus CDC guidelines on active ingredients and known health effects.

    Download PDF
    Going Forward

    What the Research Means for Policy and Practice

    The findings provide clear direction for decision-makers, healthcare providers, and institutions on how to better support people with MCS — during public health emergencies and beyond.
  • 01

    Implement fragrance-free and least-toxic cleaning alternatives

    Public health messaging and institutional cleaning protocols should include fragrance-free, nontoxic or least-toxic alternatives as the default — reducing harm for people with MCS, respiratory conditions, and other chemical sensitivities without reducing effectiveness.

  • 02

    Expand remote care options as a permanent accessibility measure

    The pandemic demonstrated that remote care partially bridges access barriers for people with MCS. Telephone and online physician visits should remain available as a permanent accessibility accommodation.

  • 03

    Require clear ingredient labeling on all cleaning and disinfection products

    Full ingredient disclosure should be mandatory. People with MCS, and those making purchasing decisions on their behalf, need complete ingredient information to avoid triggering substances.

  • 04

    Include people with MCS in emergency preparedness planning

    Future public health emergency responses should account for populations with chemical sensitivities from the outset — including guidance on accessible disinfection and supply of fragrance-free products.

    • Continue Learning

    Explore More in the Learn Section

    Learn

    What Is MCS?

    Understanding the condition, mechanisms, and how it differs from allergies
    Learn

    Symptoms & Triggers

    Common triggers, multi-system symptoms, and sensitization explained
    Learn

    Indoor Air Quality

    VOCs, chemical exposures, and the built environment
    Live & Manage

    Safer Products Guide

    Choosing fragrance-free, lowest-emission alternatives for daily living

    Everyone deserves the right to know.