# From Invisibility to Inclusion: Evidence, Lived Experience, and Policy Directions for Multiple Chemical Sensitivity Report from the Resilience 2025 International Conference

## TL;DR

This conference report highlights the public health crisis of Multiple Chemical Sensitivity (MCS), emphasizing the need for greater awareness, research, and inclusive policies to support affected individuals.

## Contribution

The report integrates scientific evidence and lived experience to advocate for MCS recognition and policy changes promoting environmental health and inclusion.

## Key findings

- MCS affects millions globally but is under-recognized in healthcare and policy.
- Fragrance and chemical exposures are significant environmental health risks requiring preventive measures.
- Conference participants emphasized the intersection of MCS with accessibility, gender equity, and human rights.

## Abstract

Public health relevance—How does this work relate to a public health issue?
The conference report highlights a groundbreaking 2-day event focusing on Multiple Chemical Sensitivity (MCS), a recognized disability which affects over a million Canadians (Canadian Community Health Survey, 2020), and millions more around the world, but it does not garner enough attention from the scientific community or policymakers.The report also highlights the underrecognized effects of fragrances and presents unique research about toxins in ubiquitous products and the benefits of fragrance-free policies.

The conference report highlights a groundbreaking 2-day event focusing on Multiple Chemical Sensitivity (MCS), a recognized disability which affects over a million Canadians (Canadian Community Health Survey, 2020), and millions more around the world, but it does not garner enough attention from the scientific community or policymakers.

The report also highlights the underrecognized effects of fragrances and presents unique research about toxins in ubiquitous products and the benefits of fragrance-free policies.

Public health significance—Why is this work of significance to public health?
MCS is a public health crisis that leads to disabling symptoms upon exposure to certain volatile organic compounds (VOCs) and other chemicals, affecting access to fundamental resources such as healthcare, dental care, housing, employment, and education, in addition to a loss of social belonging and quality of life.This report is an amalgamation of the knowledge presented during the conference, educating the public about the legitimate causes, effects, symptoms, and treatments of MCS, while presenting policies which promote inclusion and access for those affected.

MCS is a public health crisis that leads to disabling symptoms upon exposure to certain volatile organic compounds (VOCs) and other chemicals, affecting access to fundamental resources such as healthcare, dental care, housing, employment, and education, in addition to a loss of social belonging and quality of life.

This report is an amalgamation of the knowledge presented during the conference, educating the public about the legitimate causes, effects, symptoms, and treatments of MCS, while presenting policies which promote inclusion and access for those affected.

Public health implications—What are the key implications or messages for practitioners, policy makers and/or researchers in public health?
Researchers and public health institutions should allocate more resources to prioritize evidence-based MCS-focused research rooted in physiological effects and knowledge translation to address gaps in the evidence, reduce stigma, and support inclusive public health policies that protect vulnerable populations.Public health practitioners and policymakers must recognize fragrance and chemical exposures as avoidable environmental health risks and implement preventive measures such as scent-free policies, lowest-VOC-emission and least-toxic-product policies, advocate for product content transparency and indoor air quality guidelines that depend on appropriate product choices.

Researchers and public health institutions should allocate more resources to prioritize evidence-based MCS-focused research rooted in physiological effects and knowledge translation to address gaps in the evidence, reduce stigma, and support inclusive public health policies that protect vulnerable populations.

Public health practitioners and policymakers must recognize fragrance and chemical exposures as avoidable environmental health risks and implement preventive measures such as scent-free policies, lowest-VOC-emission and least-toxic-product policies, advocate for product content transparency and indoor air quality guidelines that depend on appropriate product choices.

Organized by the Environmental Health Association of Canada (EHAC-ASEC) and the Environmental Health Association of Quebec (ASEQ-EHAQ), Resilience: An International Conference on Multiple Chemical Sensitivity, a groundbreaking event, was held online over two days, on 1 and 2 May 2025, and brought together experts and stakeholders from multiple sectors to address a condition that has received limited attention in health, policy and research contexts. The conference convened leading international researchers, legal experts, medical professionals, policymakers, and advocates to examine one of the most pressing but under-represented public health and human rights challenges of our time. Multiple Chemical Sensitivity (MCS) is a disabling condition affecting a growing number of individuals globally. Despite its prevalence, MCS remains marginalized and under-recognized in healthcare systems, policy frameworks, and scientific discourse. The conference spanned 2 days, drew nearly 900 participants, and featured engaging presentations and discussions that integrated scientific evidence, lived experience, and cross-sector perspectives. A central theme emerged: recognition of MCS extends beyond medical considerations, encompassing accessibility, gender equity, environmental justice and human rights.