Table of Contents
Exposure Limits to Chemical and Biological Agents
Last updated: July 2022
Prepared by CCOHS
The following are the references to the provincial and federal legislation where you would find the occupational exposure limits for the different jurisdictions in Canada. Since legislation is amended from time to time, the jurisdictions should be contacted for the most current information about the exposure limits and how they are enforced. Since legislation interpretation and enforcement varies by jurisdiction, contact your jurisdiction as listed in Canadian Government Occupational Health & Safety Departments (http://www.ccohs.ca/oshanswers/information/govt.html) for additional information.
The ACGIH (American Conference of Governmental Industrial Hygienists) Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices are available from:
3640 Park 42 Drive
Cincinnati Ohio 45241 USA
Tel: (513) 742-2020
This list is prepared by CCOHS as part of the Canadian enviroOSH Legislation service. This service is a comprehensive and easy to search compilation of the full text of Canadian health, safety and environmental legislation and critical guidelines and codes of practice from all jurisdictions. All the legislation is compiled into one convenient location and is regularly updated with amendments highlighted.
Subscribers to this service and paid learners of the CCOHS e-courses have access to the full text of the legislation listed in this document. To become a subscriber please contact Client Services.
The occupational exposure limits that apply to employees covered by Canada Labour Code are the ACGIH TLVs and BEIs, as amended, which are referenced in section 10.19 of Canada Occupational Health and Safety Regulations (SOR/86-304) made under the Canada Labour Code Part II (R.S.C. 1985, c. L- 2). The ACGIH Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) should be consulted for specific exposure limits.
The TLVs of the ACGIH have been adopted for the purposes of the following Federal Regulations:
Aviation Occupational Safety and Health Regulations
Maritime Occupational Health and Safety Regulations (SOR/2010-120)
On Board Trains Occupational Health and Safety Regulations (SOR/87-184)
Oil and Gas Occupational Safety and Health Regulations (SOR/87-612)
As made under the Occupational Health and Safety Act (S.A. 2020, c. O-2.2),
Occupational Health and Safety Code (Alta. Reg. 191/2021)
Part 4, Chemical Hazards, Biological Hazards and Harmful Substances
Schedule 1 — Table 2
Substances and processes requiring a code of practice are listed in Table 1 .
The effects of unusual work schedules and concurrent exposures on Occupational Exposure Limits (OELs), July 2011
Employers’ guide on how to conduct a worker exposure assessment for silica, February 1, 2017
Personal exposure monitoring for ionizing radiation (dosimetry) : OHS information for employers and workers, December 1, 2021
Protective action criteria : a review of their derivation, use, advantages and limitations, January 1, 2017
As made under the Workers' Compensation Act (R.S.B.C. 1996, c. 492),
Part 5, Chemical Substances and Biological Agents and Sections 5.48 - 5.59 reference current ACGIH values except where otherwise determined by the board in the Occupational Health and Safety Regulations (B.C. Reg. 296/97).
Guide to Occupational Health and Safety Information in British Columbia (Seventh Edition 2010)
OHS Guidelines Part 5: Chemical Agents and Biological Agents
OHS Guidelines Part 6: Substance Specific Requirements
Table of Exposure Limits for Chemical and Biological Substances
Occupational exposure limits are referenced in Section 36.5 of the Workplace Safety and Health Regulation (Man. Reg. 217/2006) made under the Workplace Safety and Health Act (R.S.M. 1987, c. W210).
When available, employers are expected to establish OELs that do not exceed the ACGIH TLVs. There is also a requirement for employers, in some circumstances, to set their own occupational exposure limits to ensure workers are not exposed to health hazards.
Bulletin 153: Abrasive Blasting
Bulletin 173: Protecting against hydrogen sulphide (H2S) exposure in the petroleum industry
Bulletin 198: Carbon monoxide poisoning
Bulletin 217: Roofing Operations - health hazards of asphalt to building
Bulletin 238: Health hazards of wood dust
Bulletin 251: Respiratory protection and biological materials
Bulletin 299: Dangers of breathing silica dust
Bulletin 300: Dangers of Anhydrous Ammonia (NH3)
Bulletin 319: Anhydrous ammonia (NH3) – Safety on the Farm
Chemical and Biological Hazards Guideline
Guide for Asbestos Management
Investigation, Assessment and Remediation of Mould in Workplaces
Safety Topics: Biological
Safety Topics: Carbon Monoxide
Safety Topics: Chemical
The term "threshold limit value" as defined in section 2’s references to the ACGIH’s TLV’s ("1997 Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices")
As made under the Occupational Health and Safety Act (S.N.B. 1983, c. O-0.2),
General Regulation (N.B. Reg. 91-191)
Sections 23 - 25 .
DANGER: Carbon Monoxide
CO2 Exposure in Potato Barns
”The Employer” [legislative analysis]
Interpretations: Biological, Physical and Chemical Agents – Definition and Reporting Requirements
Interpretations: Definitions of Explosion
Microbials and Indoor Air Quality
Occupational Respiratory Disease
Safety Talk – 10: Propane
Safety Talk – 12: Carbon Monoxide
Newfoundland and Labrador
The ACGIH TLVs "currently established by "ACGIH" are referred to (but not listed) in :
Occupational Health and Safety Act (R.S.N.L. 1990, c. O-3)
Occupational Health and Safety Regulations, 2012 (N.L.R. 5/09)
Also mentioned in:
Section 12, Occupational health and safety program [subsection 12(1)(h)]
Section 46, Silica regulation
Section 47, Silica medical surveillance
Section 48, Asbestos
Section 49, Lead exposure control plan
Section 512, Corrective precautions
The Employer: Occupational Disease
The Worker: Occupational Disease
Part 21, Chemical and Biological Substances of the Occupational Health and Safety Regulations (R-039-2015) under the Safety Act (R.S.N.W.T. 1988, c. S-1) makes specific reference to the occupational exposure limits as set out in Schedules Q, R and O . There are also specific regulations for silica, sandblasting safety and asbestos safety.
The ACGIH TLVs are referenced in :
Occupational Health and Safety Act (S.N.S. 1996, c. 7),
Occupational Health of the Workplace Health and Safety Regulations (N.S. Reg. 52/2013)
Lead in the Workplace: A Guide to Working with Lead Code of Practice (Revised September 18, 2015)
Asbestos in the Workplace: A Guide to Assessment & Management of Asbestos in the Workplace (Revised November 21, 2013)
Asbestos in the Workplace: A Guide to Removal of Friable Asbestos Containing Materials (Revised November 21, 2013)
Part 21 Chemical and Biological Substances of the Occupational Health and Safety Regulations (R-003-2016) under the Occupational Health and Safety Act (R.S.N.W.T. 1988, c. S-1) makes specific reference to the occupational exposure limits as set out in Schedules Q, R and O . There are also specific regulations for silica sandblasting safety and asbestos safety.
The exposure limits are listed in section 4 of the Regulation respecting Control of Exposure to Biological or Chemical Agents (O. Reg. 833 of R.R.O. 1990) under the Occupational Health and Safety Act (R.S.O. 1990, c.O.1).
Exposure limits and certain regulatory requirements regarding some other chemicals are found in the Designated Substances Regulation (O. Reg. 490/09) made under the Occupational Health and Safety Act. ACGIH TLVs are to be applied if an agent is not listed in the Ontario Table.
There are also specific regulations for silica safety.
Current Occupational Exposure Limits for Ontario Workplaces Required under Regulation 833
Prince Edward Island
ACGIH TLVs and BEIs (2019 edition of the publication "Threshold Limit Values and Biological Exposure Indices") are referenced (but not listed) in Section 11.3 of the Occupational Health and Safety Act General Regulations (E.C. 180/87) made under the Occupational Health and Safety Act (R.S.P.E.I. 1988, c. O-1.01).
Prevention Update: Ammonia (NH3) Gas Exposure in the Workplace
Permissible exposure values for gases, dusts, fumes, vapours or mists in the work environment are referenced in:
section 41 and Schedule I of the Quebec Regulation respecting occupational health and safety (O.C. 885-2001) , and
Schedule A, Permissible Exposure Values for Gases, Dusts, Fumes, Vapours or Mists in the Work Environment of the Regulation respecting the quality of the work environment (CQLR, c. S-2.1, r. 11)
Both regulations were made under the Act Respecting Occupational Health and Safety (CQLR c. S-2.1)
Part 21 of the Occupational Health and Safety Regulations, 2020, ( c. S-15.1 R.10), made under the Saskatchewan Employment Act (S.S. 2013, c. S-15.1), refers to Tables 16 (Notifiable Chemical and Biological Substances), 17 (Designated Chemical Substances) and 18 (Contamination Limits).
Part 23, Asbestos
Part 24, Silica Processes and Abrasive Blasting
Section 27 "Air Contaminants" refers to tables 8 to 15 which list permissible concentrations in Occupational Health Regulations (O.I.C. 1986/164) made under the Occupational Health and Safety Act (R.S.Y. 2002, c. 159).
OSH Answers Fact Sheets (CCOHS)
Chemicals and Materials
Podcasts - Health and Safety To Go!
Chemical Hazard Assessment and Prioritization
Carbon Monoxide: Odorless, Colourless, and Deadly