Caring for Patients with Multiple Chemical Sensitivity (MCS)

Practical, evidence-informed guidance to support safer, more inclusive clinical care.

For patients living with Multiple Chemical Sensitivity (MCS), environmental exposures can create significant barriers to receiving it.

Everyone deserves access to healthcare.

Accessible Canada Act · 2019

Are You 2040 Ready?

Canada’s barrier-free deadline applies to all federally regulated sectors — including healthcare. Over 1.13 million Canadians live with MCS. The time to act is now.

Barrier-Free Deadline Accessible Canada Act

Canadians with MCS Statistics Canada, CCHS 2020

0 M

More Likely to report poor health

0 X

Not Working vs. 24% general population

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Healthcare institutions receiving federal funding must meet accessibility requirements — including environmental accommodations for patients with MCS.

WHY THIS MATTERS

Why Supporting Patients with MCS Matters in Healthcare Settings is Important

Multiple Chemical Sensitivity (MCS) is a chronic condition in which individuals experience symptoms triggered by low levels of environmental chemicals including at low levels.

Common triggers include volatile organic compounds (9VOCs) and other chemicals found in:

For some patients, healthcare environments themselves may provoke symptoms. This can contribute to delayed care, avoidance of medical visits, and worsening health outcomes.

Healthcare professionals play an essential role in recognizing multiple chemical sensitivity and supporting safer care environments.

UNDERSTANDING VOCs IN CLINICAL SETTINGS

What Are VOCs?

Volatile Organic Compounds (VOCs) are chemicals that easily evaporate into the air from common products such as cleaning agents, paints, disinfectants, fragrances, and building materials.

In healthcare environments, VOC exposure may occur from:

VOC Reference Table

The table below outlines common VOC sources found in indoor environments in office spaces. It is provided to support environmental awareness in clinical settings and is not intended as a diagnostic tool.

Trigger Category	Common Sources	Example Chemical Compounds	Potential Patient Impact
Fragrances & Scented Products	Perfume, deodorant, scented lotions, laundry detergents	Limonene (C10H16), Linalool (C10H18O), Benzyl Alcohol (C7H8O)	Headaches, dizziness, respiratory irritation, neurological symptoms
Cleaning Agents & Disinfectants	Bleach, ammonia cleaners, surface disinfectants	Sodium Hypochlorite (NaOCl), Ammonia (NH3), Quaternary Ammonium Compounds	Shortness of breath, throat irritation, eye irritation
Air Fresheners	Plug-ins, diffusers, aerosol sprays	Formaldehyde (CH2O), Phthalates, Ethanol (C2H6O)	Exacerbation of asthma, fatigue, nausea
Building Materials	Paint, adhesives, sealants, flooring	Toluene (C7H8), Xylene (C8H10), Formaldehyde (CH2O)	Chronic irritation, cognitive symptoms, skin reactions
Volatile Organic Compounds (VOCs)	Solvents, fuels, industrial emissions	Benzene (C6H6), Acetaldehyde (C2H4O), Styrene (C8H8)	Systemic symptoms, neurological effects, respiratory distress
Personal Care Products	Hair spray, cosmetics, shaving products	Propylene Glycol (C3H8O2), Parabens, Synthetic Fragrance Blends	Skin irritation, headaches, inflammatory response

Evidence for Action

Why Scent-Free Policies Work

Research shows scent-free policies significantly reduce indoor chemical exposure.

VOC Charts

TVOCs by Office Space

Average concentration μg/m³ (24hrs)

With Scent-Free Policy

Washroom

~350

Office

~280

Meeting

~420

No Policy

Washroom

~1100

Office

~1200

Meeting

~1250

Washroom

Office

Meeting room

⚠ Recommended limit: ≤ 500 μg/m³ daily average (Cleary et al., 2017)

70%

lower average TVOC levels
in scent-free spaces

Health Canada's Listed Hazardous VOCs by Office Space

Concentration μg/m³ (24hrs) — With Policy vs. No Policy

Isopropyl Alcohol

~16

~92

Acetone

~28

~68

Acetaldehyde

~18

~35

Formaldehyde

~12

~17

Toluene

~15

~21

m/p-Xylene

~12

~19

Benzene

2-Butanone

With Policy

No Policy

Includes EDCs, teratogens, and carcinogens — compounds that exacerbate asthma and COPD symptoms.
Sources: EPA; IARC; Health Canada 2024; Molot et al., 2023; Zaniboni & Toftum, 2023; Lv et al., 2023

The evidence is clear — scent-free policies reduce harmful chemical exposure.

A brief environmental screening can significantly improve patient access and safety.

Simple Screening Questions for Providers

A brief environmental screening can significantly improve patient access and safety.

Consider asking:

Do you experience symptoms when exposed to fragrances, cleaning products, or other chemical or scented products?
Are there specific environments where your symptoms worsen?
Are there particular exposures we should be aware of to help make this visit safer for you?
Do cleaning products or chemicals trigger reactions?
Are there accommodations that would help you access care safely?

Our clinic follows a fragrance-free and lowest-emission approach. We focus on source control — choosing fragrance-free and lowest-emission products — rather than relying on ventilation after chemicals are released.

Would these measures address your main concerns, or are there additional precautions that would support your access to care?

A simple question, combined with fragrance-free and lowest-emission practices, can prevent avoidable exposures and reduce barriers to care.

Practical guidance for safer, fragrance-aware care

Step-by-step provider approach

Step 1 — Ask

Screen for environmental triggers during intake. Ask about reactions to fragrances, cleaning products, and other chemical exposures.

Step 2 — Document

Clearly record MCS in the patient file.

Step 3 — Reduce Exposure

Prevent exposures at the source by eliminating scented products, avoiding spraying in patient areas, and choosing fragrance-free, lowest-emission alternatives rather than relying on ventilation after release.

Step 4 — Accommodate

Adjust scheduling, room preparation, or care delivery when feasible.

Step 5 — Follow Up

Assess symptom impact after the visit and note effective exposure-reduction measures to support safer future care.

Role-specific guidance for healthcare teams

Different healthcare roles interact with patients in different ways. The guidance below provides practical considerations tailored to specific care settings.

Nurses are often the first point of contact and play a central role in identifying MCS.

Screen
• Ask about fragrance and chemical triggers during intake
• Identify common environmental exposures

Document
• Clearly record MCS in the patient file
• Flag environmental needs

Reduce Exposure
• Eliminate scented personal products
• Avoid aerosolized sprays in patient areas, and choose only fragrance-free, lowest-emission alternatives • Use non-latex, least-toxic supplies
• Ensure ventilation after cleaning

Communicate
• Inform colleagues of MCS during handoff
• Validate and acknowledge patient-reported reactions

Emergency responders may encounter patients experiencing acute reactions to environmental exposures (perfume, first, second, or third-hand smoke).

Recognize
• Consider environmental triggers when symptoms follow exposure

Reduce Immediate Exposure
• Move the patient away from triggering substances
• Avoid spraying products in enclosed spaces

Ask
• Inquire about known triggers
• Ask what has helped previously

Document
• Record MCS and symptoms clearly
• Communicate environmental needs during transfer of care

Physicians play a critical role in validating patient experiences and coordinating care.

Screen
• Incorporate environmental health questions into the assessment

Assess Impact
• Document functional limitations
• Note symptom patterns – these may change as condition progresses

Coordinate
• Inform care teams of MCS
• Consider environmental exposures when planning care

Support Accommodations
• Provide clear clinical documentation outlining diagnosis (where appropriate), and medically necessary environmental or source-control measures
• Support workplace or disability accommodation processes

Procedural environments may involve disinfectants, sterilizing agents, and materials that can trigger symptoms.

Pre-Procedure
Screen for MCS and document known triggers
Remove or substitute triggering disinfectants, sterilants, or materials before the procedure

Prepare the Environment
• Eliminate fragranced products in the procedural area and adjacent corridors • Do not use aerosolized or triggering chemical products in or near areas the patient will access, including hallways and preparation spaces
• Complete necessary cleaning well in advance of patient arrival using fragrance-free, low-emission products • Use non-latex supplies when indicated

Post-Procedure
• Transfer documented triggers and required precautions to recovery staff • Monitor for symptom exacerbation and reassess the environment if symptoms occur

Emergency departments can present heightened exposure risks due to crowding, frequent cleaning, disinfectants, fragranced products, and limited environmental control. For patients living with MCS, these exposures may trigger significant symptom escalation.

Environmental exposure control in emergency care should be treated as a patient safety and accessibility consideration.

Key Principles

Screen for MCS and clearly flag environmental triggers at triage
Relocate patients to the lowest-exposure space available and avoid hallway placement
Provide private room access at no additional cost when needed for accessibility
Do not spray or apply chemical products near patient areas
Use fragrance-free bedding and lowest-emission equipment
Post fragrance-free signage and limit room entry during acute symptom periods
Document and reassess environmental factors if symptoms escalate

Proactive environmental control reduces preventable harm and supports equitable access to emergency care.

Creating Safer Clinical Environments

Source control can significantly reduce exposure risks.

Fragrance-Free Practices

Cleaning and Disinfection

Use fragrance-free, lowest VOC emission and least-toxic products compatible with infection prevention standards
Do not use aerosolized or spray-applied products in areas the patient will access
Complete cleaning well in advance of patient arrival and ensure products have fully dried and off-gassed before occupancy

Communication

Healthcare Professionals Living With MCS

Healthcare professionals may also experience MCS. Clinical environments can present challenges related to fragrances, cleaning products, disinfectants, and building materials.

Creating safer environments supports both patient care and workforce inclusion.

If You Are a Healthcare Worker with MCS

You may consider:

Documenting Your Needs

Keep records of triggers and symptom patterns
Obtain medical documentation outlining functional limitations and required exposure-reduction measures

Requesting Accommodation

Inform your supervisor or department lead of your need for workplace accommodation
Provide medical documentation, if requested, outlining required source-control measures
Request specific environmental adjustments (e.g., fragrance-free policy enforcement, lowest-emission products, modified cleaning practices, workstation adjustments)

Collaborating on Safer Policies

Advocate for fragrance-free and lowest-emission practices
Support procurement and use of fragrance-free, lowest-VOC-emission, and least-toxic products compatible with infection prevention standards
Promote education within teams about chemical exposures, source control, and inclusive clinical environments

Patient Safety Tools

Individuals with MCS may carry:

A Medic Alert bracelet indicating multiple chemical sensitivity (MCS)
A written accommodation card outlining triggers and required precautions
Requests for fragrance-free, lowest-emission, least-toxic, or non-latex care
A personal low-exposure kit (e.g., mask, fragrance-free supplies)

Respecting and reviewing these tools supports patient-centred care.

Clinical Considerations and Research

MCS may involve multi-system symptoms and complex diagnostic considerations. Research continues to explore neurological, immunological, and environmental mechanisms.

Providers may encounter:

Understanding environmental health factors supports more comprehensive and inclusive care.

Education & Professional Training

Limited recognition of MCS in clinical practice is often linked to gaps in medical education and continuing professional development.

Medical Students & Trainees

Integrating MCS into undergraduate and postgraduate curricula can improve diagnostic accuracy, reduce misattribution of symptoms, and strengthen patient trust.

Training should include:

Clinical presentation and functional impact of MCS
The role of chemical exposures in symptom exacerbation
Source-control approaches in healthcare settings
Ensure clinical communication reflects objective assessment of reported environmental exposures and supports patient safety

Practicing Physicians & Healthcare Providers

Continuing professional development should include:

Education is a foundational step toward reducing healthcare inequities and improving inclusive clinical environments.

Access to Care

Access to health care is essential.

Patients living with MCS may delay or avoid medical care due to exposure risks, limited recognition of the condition, and barriers within clinical environments. Inclusive fragrance-free and lowest-emission healthcare settings reduce preventable barriers and support health equity.

Even small environmental adjustments can significantly improve patient safety, dignity, and access to care.

National data (CCHS 2015–2016) show that Canadians living with MCS are three times more likely to report poor health and face significantly higher barriers to care, including service unavailability, high costs, lack of a regular provider, and transportation challenges. They are also more likely to require specialist diagnosis yet experience greater difficulty accessing specialist services. Higher levels of pain and sleep disruption further compound health inequities.