Residential Indoor Air Quality Guidelines

The Residential Indoor Air Quality Guidelines summarize the health risks posed by specific indoor pollutants, based on a review of the best scientific information available. They summarize the known health effects, detail the indoor sources, and where possible, provide a recommended exposure level below which health effects are unlikely to occur. The Guidelines are recommendations only and are meant to serve as a scientific basis for activities to reduce the risk from indoor air pollutants.

Health Canada first issued risk assessment and management guidelines on indoor air pollutants in 1987 in the Exposure Guidelines for Residential Indoor Air Quality (1987). These guidelines are currently being reviewed and updated. New guidelines will also be posted on this web site as additional pollutants are assessed.

If you have any questions about the Residential Indoor Air Quality Guidelines or would like to request the full scientific assessment documents on which they were based, please contact us.

Further technical reports on Indoor Air Quality are available in the Resource Centre.

Summary of Recommended Exposure Limits

The table below provides Health Canada's recommended exposure limits from the Residential Indoor Air Quality Guidelines.

Some pollutants have two exposures limits:

• A long-term exposure limit to protect against health problems that may develop from continuous or repeated exposure over a long period (days, weeks, months, etc.).
• A short-term exposure limit to protect against health problems that may occur immediately from a brief exposure (hours) to high levels, for example, when working with a household product such as paint or glues.

A recommended sampling time to measure exposure is also given where available [shown in square brackets] e.g. [8 hour]. For long-term exposure limits, the value given is a recommended minimum sampling time. Longer sampling times and averaging repeated samples would provide a more representative measure of actual long-term exposure.

Use the links in the table below to view summaries of each guideline or to learn more about each contaminant.

Recommended Exposure Limit

Contaminant	Maximum exposure limits [recommended sampling time] or Recommendations	Date of issue
Formaldehyde Read the Guideline Read More About Formaldehyde	Long-term [8 hour]: 50 µg/m3 (40 ppb) Short-term [1 hour]: 123 µg/m3 (100 ppb)	2006
Mould Read the Guideline Read More About Mould	Health Canada recommends: To control humidity and diligently repair any water damage in residences to prevent mould growth; and To clean thoroughly any visible or concealed mould growing in residential buildings.	2007
Carbon Monoxide Read the Guideline Read More About Carbon Monoxide	Long-term [24 hour]: 11.5 mg/m3 (10 ppm) Short-term [1 hour]: 28.6 mg/m3 (25 ppm)	2010
Nitrogen Dioxide Read the Guideline	Long-term [24 hour]: 100 µg/m3 (0.05 ppm) Short-term [1 hour]: 480 µg/m3 (0.25 ppm)	1987
Ozone Read the Guideline Read More About Ozone	Long-term [8 hour]: 40 µg/m3 (20 ppb)	2010
Fine Particulate Matter (PM2.5) Read the Guidance Document	Health Canada recommends: Indoor levels of PM2.5 should be kept as low as possible.  To address the main indoor sources use a stove top fan while cooking and do not allow smoking indoors.	2012
Toluene Read the Guideline Read More About Toluene	Long-term [24 hour]: 2.3 mg/m³ (0.6 ppm) Short-term [8 hour]: 15 mg/m³ (4.0 ppm)	2011

Other Resources

•  U.S. EPA Indoor Air Pollution: An Introduction for Health Professionals
•  National Collaborating Centre for Environmental Health (NCCEH): Health Effects for Mould Exposure in Indoor Environments
•  World Health Organization Indoor Air Pollution website
•  Agence nationale de sécurité sanitaire, de l'alimentation, de lènvironnement et du travail (France) Indoor Air : Guide Values [in English]