Indoor air in residential premises may contain various volatile organic compounds (VOCs) which may pose a risk to human health at certain exposure concentrations. Therefore, Health Canada has specified exposure limit values for a small number of VOCs such as benzene, formaldehyde, naphthalene, toluene and acetaldehyde in its Residential Indoor Air Quality Guidelines. These VOCs are prioritised in the assessment as they are often present in indoor air and pose potential health risks.
These Residential Indoor Air Quality Guidelines were published in 2006. They contain information on
- known health effects of indoor air contaminants
- indoor sources of air contaminants
- recommended exposure limits
- recommendations to reduce your exposure to pollutants
For the time being, testing to ensure compliance with the Canadian guidelines is voluntary.
However, a regulation for requirements for derived timber products is currently being drawn up – this regulation is expected to comply with the US specification of TSCA title VI. The draft of the regulation could be commented on until September 12, 2019. The draft of the regulation can be found on this page under the tab ‘Links’.
To assist healthcare professionals, including those involved in the development of standards and who may need to assess the potential risk of exposure to other VOCs in indoor air, Health Canada further developed screening values known as Indoor Air Reference Levels (IARLs). The IARLs are intended to complement Health Canada’s Residential Indoor Air Quality Guidelines.
Residential Indoor Air Quality Guidelines: recommended exposure limits
The recommended exposure limits of the Residential Indoor Air Quality Guidelines refer to a short-term exposure limits (usually one hour) and a long-term exposure limits (usually 24 hours).
||Short exposure duration (in μg/m3)*||Long exposure duration (in μg/m3)*|
|Acetaldehyde||after 1 hour ≤ 1420
||after 24 hours: ≤ 280|
|Benzene||Indoor levels must be kept as low as possible|
|Carbon monoxide|| nach 1 Stunde: ≤ 11.5
||nach 24 Stunden: ≤ 28.6|
|Formaldehyde||nach 1 Stunde ≤ 123||nach 8 Stunden: ≤ 50|
|Fine particular matter (PM 2.5)||Indoor levels must be kept as low as possible | During cooking, use an stovetop fan exhausting outdoors and do not allow smoking indoors
|Mould||Address any water damage in residences within 48 hours to prevent mould growth | address any visible or concealed mould growing in residential buildings
|Naphthalene||after 24 hours: ≤ 10|
|Nitrogen dioxide||after 8 hours: ≤ 170||after 24 hours: ≤ 20|
|Ozone||after 8 hours: ≤ 40|
|Radon||Exposure limit: ≤ 200 Bq/m3|
|Toluene||after 8 hours: ≤ 15 mg/m3||after 24 hours: ≤ 2.3 mg/m3|
*unless otherwise stated
Indoor Air Reference Levels (IARLs)
To determine IARLs, Health Canada evaluated assessments developed by internationally recognised health and environmental organisations. Health Canada did not carry out any new risk assessments for the IARLs and chose only the most relevant reference level set by other companies. The IARLs listed below represent concentrations associated with acceptable risk levels after long-term exposure (over several months or years) for each specific VOC as determined by the company that performed the risk assessment. The link to the IARLs on Health Canada’s page can be found on this page under the ‘Links’ tab.
Source & image: ©Health Canada
Subject to change without notice; last update: March26, 2020