# J22 Exposure Limits, Heat and Cold Stress > Fire Service Safety Management System, version 0.3.3 (2026-10-25). The Human Factor. Document FSSMS-JUR-22. > > Canonical: https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress > > Licence: CC BY-NC-SA 4.0 with the Adopting Agency Grant (https://creativecommons.org/licenses/by-nc-sa/4.0/) > > General information only, not legal, medical or other professional advice. Verify every requirement against the current official text of the law, standards and manufacturer instructions that apply to you. Obtain your own legal review and consult your joint health and safety committee before adopting anything. You adopt, adapt, implement and rely on this material entirely at your own risk and on your own responsibility. Full terms: Terms of Use, thehumanfactor.ca. > **Warning: Law changes; verify before you rely on this page** > > This page summarizes what each jurisdiction’s law requires on this topic as of 2026-10-23. It is general information, not legal advice. Check the official text for your jurisdiction before you adopt or rely on anything here. See [00a Copyright, Licence and Legal Notices](https://thehumanfactor.ca/library/fire-service-safety/copyright-licence-and-legal-notices). ## What this topic covers Where each jurisdiction gets its occupational exposure limits for chemical and physical agents, and what it requires for heat and cold. Roughly half the jurisdictions adopt the threshold limit values (TLVs) of the American Conference of Governmental Industrial Hygienists (ACGIH), but they differ on the edition: some take the latest edition automatically, some pin a past year (2016, 2017, 2019), and some keep their own tables. Heat and cold rules range from the ACGIH heat stress and cold stress TLVs adopted by name, through provincial work-rest tables, to a general duty to keep thermal conditions reasonable. The page also covers how limits are adjusted for shifts longer than eight hours and where the official weather alerts come from. ## Why it matters to a fire department The adopted limits are the legal yardstick for carbon monoxide and hydrogen cyanide during overhaul, diesel exhaust in apparatus bays, solvents and cleaners in the decontamination area, and the work-rest cycle at a summer fire or a training evolution in bunker gear. Firefighters on 24-hour shifts sleep and eat in the same building as the apparatus, so the rules for adjusting an eight-hour limit to a longer work period matter. The common misunderstanding is that the ACGIH numbers on a gas monitor’s default alarm settings are the law: the legal limit is whatever your jurisdiction adopted, which may be an older edition or a provincial table with different values. The second is that heat stress rules stop at the fireground; they apply equally to training, to station work in summer and to rehabilitation. ## What every department must cover, wherever it is 1. Know which exposure limits your jurisdiction adopts (ACGIH latest edition, a pinned ACGIH edition, or a provincial table) and set gas monitor alarm points and overhaul clearance criteria at or below them (see the At a glance table). 2. Adjust eight-hour limits for long work periods by the method your jurisdiction prescribes, and get industrial hygiene advice for 24-hour shifts rather than applying a formula mechanically (see your jurisdiction below). 3. Assess and control diesel exhaust in apparatus bays and living quarters; check whether your adopted table has a value for diesel particulate or its components, and apply the station rules in [J20 Stations, Premises and Building Codes](https://thehumanfactor.ca/library/fire-service-safety/j20-stations-premises-and-building-codes). 4. Monitor overhaul atmospheres and keep respiratory protection on until readings are below the adopted limits (see [J14 Respiratory Protection, Fit Testing and Breathing Air](https://thehumanfactor.ca/library/fire-service-safety/j14-respiratory-protection-fit-testing-and-breathing-air)). 5. Write a heat stress procedure that uses your jurisdiction’s criteria (the ACGIH heat stress TLV or the provincial table), covering acclimatization, work-rest cycles, water, cooling, and removal and first aid for members with symptoms (see your jurisdiction below). 6. Write a cold stress procedure covering wind chill, warm-up breaks, heated shelter, dry clothing and cold-water immersion at water and ice incidents (see your jurisdiction below). 7. Provide rehabilitation at incidents and training to NFPA 1580, whose rehabilitation chapter replaced NFPA 1584 [(NFPA 1580, 2025)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-nfpa-1580), and fit it to the legal heat and cold criteria above. 8. Subscribe to the official weather alerts for each response area and tie them to the heat and cold procedures; Environment and Climate Change Canada sets heat and extreme cold warning criteria by region (Environment and Climate Change Canada, n.d.-a). 9. Train members in the signs and symptoms of heat and cold stress and the precautions, which several jurisdictions require in so many words (see below). 10. Record incidents of heat or cold illness and exposure readings, and review them in the hazard assessment cycle (see [J04 Hazard Assessment and Workplace Inspections](https://thehumanfactor.ca/library/fire-service-safety/j04-hazard-assessment-and-workplace-inspections)). ## At a glance | Jurisdiction | Chemical exposure limits | Heat and cold rule | Long-shift adjustment | Verified | |:---|:---|:---|:---|:---| | British Columbia | ACGIH, current edition, except as the Board determines | ACGIH heat stress screening criteria; cold: ACGIH wind chill, heated shelter below -7 °C | Reduction factors from 0.7 (8-10 h) to 0.1 (over 16 h) | Yes | | Alberta | Alberta table [(Occupational Health and Safety Code \[AB\], 2025, Schedule 1, Table 2)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-code-ab) | No specific rule; hazard assessment and general duty | Formula for shifts over 8 h | Yes | | Saskatchewan | Saskatchewan table (Table 18) | General thermal duty; listed measures | Written procedure if over 8 h a day or 40 h a week | Yes | | Manitoba | ACGIH 2019 edition | ACGIH 2019 thermal stress TLVs | Not found | Partly | | Ontario | Ontario Table, then ACGIH 2017 edition | No regulation; guidance notes | IRSST method permitted | Partly | | Quebec | Quebec table [(Regulation respecting occupational health and safety \[QC\], 2026, Schedule I)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-regulation-respecting-occupational-health-and-safety-qc) | WBGT index and continuous work curve; indoor minimum temperatures | Not in regulation | Partly | | New Brunswick | ACGIH 2016 edition plus Commission limits | ACGIH 2016 heat and cold TLVs; measurement relieved during structural firefighting | Brief and Scala model | Yes | | Nova Scotia | ACGIH, latest edition | ACGIH TLVs for physical agents, heat and cold included | Per ACGIH documentation | Yes | | Prince Edward Island | ACGIH 2019 edition, “as amended from time to time” | ACGIH heat and cold TLVs | Not found | Partly | | Newfoundland and Labrador | ACGIH, latest edition | Thermal environment as established by ACGIH | Adjusted per ACGIH, with the committee | Yes | | Yukon | Yukon tables (1986 regulations) | WBGT or WGT table by work load | Modified permissible concentration over 8 h | Partly | | Northwest Territories | Territorial table (Schedule O) | General thermal duty | Written procedure if over 8 h a day or 40 h a week | Partly | | Nunavut | Territorial table (Schedule O) | General thermal duty | Written procedure if over 8 h a day or 40 h a week | Partly | | Federal | ACGIH, as amended from time to time | ACGIH heat and cold thresholds from 2027-01-30 | Not found | Yes | ## British Columbia **Law.** Occupational Health and Safety Regulation, Part 5 (exposure limits, ss. 5.48-5.54), Part 7 Division 4 (thermal exposure, ss. 7.26-7.38) and Part 31 (ss. 31.6, 31.32) [(Occupational Health and Safety Regulation \[BC\], 2026, ss. 5.48-5.54, 7.26-7.38, 31.6, 31.32)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-regulation-bc). **What must be covered.** - **Basis of limits.** No worker may be exposed above the ceiling, short-term or eight-hour limit “prescribed by ACGIH”, “except as otherwise determined by the Board” (s. 5.48). “ACGIH” means the TLV and BEI publication dated 2002 “as amended from time to time”, so the current edition applies, subject to the Board’s own determinations (s. 5.1). - **Excursions.** Where only an eight-hour limit exists, no more than three times the limit for a total of 30 minutes, and never above five times (s. 5.49). - **Long work periods.** For work periods over eight hours in a 24-hour day, the eight-hour limit is multiplied by 0.7 (over 8 to 10 hours), 0.5 (over 10 to 12), 0.25 (over 12 to 16) or 0.1 (over 16) (s. 5.50(1)). - **Mixtures, skin, monitoring.** Additive effects (s. 5.51), skin absorption (s. 5.52), exposure monitoring, and an exposure control plan where exposure may exceed 50 per cent of a limit (ss. 5.53-5.54). - **Heat.** Where workers may be exposed to heat stress, core temperature above 38 °C, or conditions above the ACGIH screening criteria for unacclimatized workers (s. 7.27), exposure must not exceed the screening criteria in the heat stress and strain section of the ACGIH standard, with clothing corrections (s. 7.28); the employer does a heat stress assessment and an exposure control plan (s. 7.29), uses engineering controls or, failing that, administrative controls and personal protective equipment (s. 7.30), supplies cool potable water close to the work area (s. 7.31), and removes and treats a worker with symptoms (s. 7.32). - **Cold.** Where conditions could cause cold stress or core temperature below 36 °C, or fall below “little danger” on the ACGIH wind chill criteria (s. 7.33), a cold stress assessment and plan (s. 7.34), controls (s. 7.35), a nearby heated shelter whenever the equivalent chill temperature is below -7 °C (s. 7.36), adequate insulating clothing (s. 7.37), and removal and treatment of a worker with symptoms (s. 7.38). - **Firefighting.** The incident commander makes suitable provision for rest and rehabilitation (s. 31.6). Apparatus bays need local exhaust venting unless monitoring shows exhaust levels below the s. 5.48 limits (s. 31.32). **Fire-service nuance.** - The s. 5.50 factors are written for continuous work periods; a 24-hour shift in which members live beside the apparatus bay is a strong argument for source-capture exhaust rather than reliance on monitoring. - WorkSafeBC’s guideline allows multi-hall departments to phase exhaust retrofits over two to three years (WorkSafeBC, n.d.). - The province runs heat alerts in addition to federal weather warnings. **Status.** Verified against the official text on 2026-10-23 (regulation consolidated to 2026-10-20), except the provincial heat alert system and the guideline wording. ## Alberta **Law.** Occupational Health and Safety Code, Part 4, ss. 16 to 20, and Schedule 1, Table 2 [(Occupational Health and Safety Code \[AB\], 2025, ss. 16-20, Sch. 1)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-code-ab). **What must be covered.** - **Basis of limits.** Exposure to a Schedule 1, Table 2 substance is kept as low as reasonably achievable and must not exceed its occupational exposure limit (s. 16(1)-(2)); ceiling limits are never exceeded (s. 16(3.1)); a substance with no listed limit is kept as low as reasonably achievable (s. 16(3)). Alberta keeps its own table rather than adopting ACGIH. - **Mixtures.** Combined exposure to several substances is assessed (s. 17). - **Long shifts.** For a single shift longer than eight hours, the eight-hour limit is adjusted by a daily reduction factor of (8 ÷ h) × ((24 − h) ÷ 16), where h is hours worked (s. 18). - **Review and measurement.** A person may ask a Director to review a limit (s. 19); airborne concentrations are measured by recognized methods (s. 20). - **Heat and cold.** The Code has no heat stress or cold stress section. Thermal hazards are handled through the hazard assessment in Part 2 and the employer’s general duty. **Fire-service nuance.** - The s. 18 factor falls to zero as h approaches 24, so it cannot be applied mechanically to a 24-hour shift; assess the actual exposure periods with an industrial hygienist. - Schedule 1 has no diesel exhaust limit, so bay exhaust is managed under the “as low as reasonably achievable” rule. - The third group of Code changes under review includes the occupational exposure limits (Government of Alberta, n.d.-e). **Status.** Verified against the Code consolidated to 2025-03-31 (read 2026-10-23), except the review status and heat guidance. ## Saskatchewan **Law.** Occupational Health and Safety Regulations, 2020, Part 21 (chemical and biological substances, Table 18 contamination limits) and s. 6-7 (thermal conditions) [(The Occupational Health and Safety Regulations, 2020 \[SK\], 2021, ss. 6-7, 21-1 to 21-6, Table 18)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-the-occupational-health-and-safety-regulations-2020-sk). **What must be covered.** - **Basis of limits.** Where a Table 18 substance is present, engineering controls so far as reasonably practicable to keep the contamination limit from being exceeded where workers usually are, and all practicable steps so no worker’s personal exposure exceeds it (s. 21-6(1)). Saskatchewan keeps its own table. - **Long hours.** A written procedure, developed with the committee, where workers regularly work more than eight hours a day or 40 hours a week, or are exposed to substances with similar effects, identifying the substances, working conditions and the steps to keep exposure within the equivalent limit (s. 21-6(2)-(4)). - **General duties.** Monitoring, substitution, reduction of contamination and safe procedures (s. 21-1). - **Heat and cold.** Indoor thermal conditions appropriate to the work (s. 6-7(1)); an instrument where the thermal environment is a concern (s. 6-7(2)); outdoors or where conditions cannot be controlled, measures that may include monitoring, shelters, clothing, hot or cold drinks, acclimatization, limited work schedules with rest and recovery, and observation by a person trained to recognize physiological stress (s. 6-7(3)-(4)); suitable clothing for unusual thermal conditions (s. 6-7(5)). **Fire-service nuance.** - Diesel engine exhaust is a designated substance in Table 17, which brings engineering controls to prevent release so far as reasonably practicable. - Part 32 has no rehabilitation rule; the s. 6-7(4) list is the closest legal anchor for work-rest cycles. **Status.** Verified against the regulations consolidated to 2021-04-01 (read 2026-10-23), except the Table 17 treatment of diesel exhaust. ## Manitoba **Law.** Workplace Safety and Health Regulation, ss. 1.1 (definition of threshold limit value), 4.12-4.13 (thermal stress) and Part 36 (chemical and biological substances) [(Workplace Safety and Health Regulation \[MB\], 2026, ss. 1.1, 4.12, 4.13, 36.1.1, 36.5)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-workplace-safety-and-health-regulation-mb). **What must be covered.** - **Basis of limits.** Where an assessment shows an airborne substance creates or may create a risk, the employer sets an exposure limit no higher than the ACGIH TLV, as close to zero as possible for designated materials, and, where ACGIH has no TLV, either controls that eliminate the risk or a limit set by a competent person (s. 36.5(1)); a lower limit where the TLV would still leave a risk (s. 36.5(2)). - **Edition.** “Threshold limit value” means the value in the ACGIH 2019 TLV and BEI publication (s. 1.1). The director must seek input every three years on the applicable TLVs (s. 36.1.1). - **Heat and cold.** Where heat or cold may create a risk, safe work procedures and controls ensuring that the ACGIH 2019 thermal stress TLVs are followed, and information, instruction and training in the symptoms of thermal stress and the precautions (s. 4.12); indoor thermal conditions appropriate to the work (s. 4.13). **Fire-service nuance.** - Firefighting is not exempt from s. 4.12, so the ACGIH heat stress TLV is the legal basis for work-rest cycles at fires and training. - No long-shift adjustment rule was found in the text searched. **Status.** Partly verified: ss. 1.1, 4.12, 4.13, 36.1.1 and 36.5 read on 2026-10-23 (current from 2026-09-01 to 2026-10-20); a long-shift rule was not found. ## Ontario **Law.** Control of Exposure to Biological or Chemical Agents, Reg. 833 [(Control of Exposure to Biological or Chemical Agents \[ON\], 2026, ss. 1, 3, 4, Sch. 1)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-control-of-exposure-to-biological-or-chemical-agents-on). Designated substances are regulated separately under O. Reg. 490/09 (not read). There is no heat or cold stress regulation; the employer’s general duty to take every precaution reasonable in the circumstances applies [(Occupational Health and Safety Act \[ON\], 1990, s. 25(2)(h))](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-act-on). **What must be covered.** - **Basis of limits.** If an agent is in the Ontario Table, exposure must not exceed its TWA, STEL or ceiling; if it is not but is in the ACGIH Table, the ACGIH value applies; where only a TWA exists, excursions are limited to three times the TWA for 30 minutes and five times at any time (s. 4). - **Edition.** The “ACGIH Table” is the “Adopted Values” table in the 2017 TLV and BEI publication (s. 1). - **Controls.** Substitution, engineering controls, administrative controls, hygiene, then personal protective equipment (s. 3). - **Long shifts.** Time-weighted averages for extended shifts may be calculated by the method in the IRSST guide for unusual work schedules (March 2015) (Sch. 1, s. 6). - **Heat and cold.** Guidance only: the Section 21 notes on heat and cold stress (GN 3-3) and rehabilitation (GN 6-12), which calls for 250 to 400 mL of fluid during rehabilitation and 500 mL at the end, and active cooling above 25 °C (MLITSD, n.d.). **Fire-service nuance.** - The Section 21 notes also cover diesel exhaust (GN 3-1), limiting exposure to fire gases (GN 6-36) and air monitoring (GN 6-51); inspectors apply the law to the facts but use the notes as the expected practice. - Ontario’s ACGIH edition is fixed at 2017, so a newer, lower ACGIH value is not the legal limit until the regulation is amended; adopt the lower value by policy. **Status.** Partly verified: Reg. 833 read on 2026-10-23 (last amendment O. Reg. 113/26); O. Reg. 490/09 and provincial heat guidance not read. ## Quebec **Law.** Regulation respecting occupational health and safety, ss. 40-43 and Schedule I (exposure values), ss. 116-124 and Schedules IV and V (temperature and heat stress) [(Regulation respecting occupational health and safety \[QC\], 2026, ss. 40-43, 116-124)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-regulation-respecting-occupational-health-and-safety-qc). **What must be covered.** - **Basis of limits.** No worker may be exposed to gases, fumes, vapours, dusts or mists beyond the limits in Schedule I (s. 40), Quebec’s own table; the employer controls air quality by elimination or substitution, then containment and other measures (s. 41); exposure to known or suspected carcinogens is reduced to a minimum even within the standard (s. 42). - **Measurement.** In establishments with 50 or more workers where a concentration exceeds or could exceed Schedule I, measurement at least once a year (s. 43). - **Heat.** The heat stress index is measured by the WBGT method in Schedule V (s. 122). In establishments with 50 or more workers where the index reaches the continuous work curve, it is measured twice a year, once in summer (s. 121). Where it exceeds the curve, workers are under medical supervision and get water at 10 to 15 °C (s. 123), and special measures apply, including re-equipping the work station (s. 124). - **Cold.** Appropriate temperatures in closed rooms, with a heated place where they cannot be maintained (s. 116), and minimum temperatures at stationary indoor work stations in Schedule IV (s. 117). **Fire-service nuance.** - The CNESST runs a heat stroke prevention campaign for firefighters, and the municipal-sector joint association offers a heat-stress prevention questionnaire and heat-strain tools (APSAM, n.d.). - The heat index rules are written for fixed work stations; for fireground work they set the method (WBGT and work curves) rather than a direct rule (interpretation). **Status.** Partly verified: the regulation read on 2026-10-23 (consolidated to 2026-07-01). The content of Schedules I, IV and V and any long-shift rule were not read. ## New Brunswick **Law.** General Regulation 91-191, s. 2 (definition of occupational exposure limit), ss. 18(3), 22-24.1 [(General Regulation: Occupational Health and Safety Act \[NB\], 2026, ss. 2, 18(3), 22, 23, 24, 24.1)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-general-regulation-occupational-health-and-safety-act-nb). **What must be covered.** - **Basis of limits.** The occupational exposure limit is the ACGIH TLV in the 2016 TLV and BEI publication, except for lead sulfide (0.15 mg/m³ TWA), formaldehyde (0.5 ppm TWA, 1.5 ppm STEL), sulphur dioxide (2 ppm TWA, 5 ppm STEL), hydrogen sulphide and the other contaminants for which the Commission sets a limit (s. 2); air contaminants must not exceed it (s. 24). - **Long shifts.** Exposure outside an eight-hour day and 40-hour week is adjusted by the Brief and Scala model referenced in the 2016 ACGIH publication (s. 24.1(1)). - **Heat and cold.** Where extreme heat or cold may present a hazard, a competent person measures and records thermal conditions at frequent intervals and makes the findings available to the committee and officers (s. 22(a)), and the ACGIH 2016 heat stress and cold stress limits, the work-rest regimen for heat and the work-warming regimen for cold are followed (s. 22(b)); a competent person instructs employees in the symptoms of heat and cold stress and the precautions (s. 23). **Fire-service nuance.** - Sections 19, 20, 24, 24.1 and 25.2 and paragraph 22(a) do not apply while a firefighter is engaged in structural firefighting (s. 18(3)). The exposure limit duty and the thermal measuring duty are relieved during structural firefighting; the ACGIH work-rest regimen in s. 22(b) and the instruction in s. 23 are not. - The relief ends when structural firefighting ends, so overhaul, investigation, training and station work are covered in full. **Status.** Verified against the regulation consolidated to 2026-06-30 (read 2026-10-23). ## Nova Scotia **Law.** Workplace Health and Safety Regulations, Part 2 (ss. 2.1-2.3) [(Workplace Health and Safety Regulations \[NS\], 2025, ss. 2.1-2.3)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-workplace-health-and-safety-regulations-ns). **What must be covered.** - **Basis of limits.** The employer must comply with, and ensure compliance with, the threshold limit values for gases, vapours, mists, fumes, smoke, dust, chemical substances and physical agents as listed in the “TLVs and BEIs”, defined as “the latest version” of the ACGIH publication (ss. 2.1, 2.3). - **Heat and cold.** “Physical agent” includes agents of a thermal nature (s. 2.1), so the ACGIH heat stress and cold stress TLVs are adopted by reference and are the legal basis for work-rest and warm-up cycles. - **Priority.** Part 2 prevails over any other provision of the regulations or any other regulation under the Act (s. 2.2). - **Weather alerts.** Federal weather alerts apply; there is no provincial duty to subscribe (Environment and Climate Change Canada, n.d.-a). **Fire-service nuance.** - There is no firefighting exemption from Part 2. The latest-edition rule means a new ACGIH value becomes the legal limit when ACGIH publishes it, so the department’s monitoring settings need an annual check. - The Safety Branch publishes heat stress and cold stress guidelines. - Long-shift adjustment follows the ACGIH documentation. **Status.** Verified: Part 2 read on 2026-10-23 (consolidated to N.S. Reg. 163/2025). The Safety Branch guidelines were not read. ## Prince Edward Island **Law.** General Regulations, s. 11.3 (threshold limit values) and Part 42 (extremes of temperature) [(Occupational Health and Safety Act General Regulations \[PE\], 2025, ss. 11.3, 42.1)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-act-general-regulations-pe). **What must be covered.** - **Basis of limits.** Where air is contaminated by vapours, fumes, gases, mists or other impurities, ventilation must reduce contamination to or below the TLVs in the 2019 edition of the ACGIH publication, “as amended from time to time” (s. 11.3). - **Heat and cold.** “Permissible heat and cold exposure shall conform to Threshold Limit Values (TLVs)” of the ACGIH (s. 42.1). **Fire-service nuance.** - The wording pairs a 2019 edition with “as amended from time to time”, so it is unclear whether later ACGIH editions apply; use the lower of the 2019 and current values by policy. - No long-shift rule was found. **Status.** Partly verified: ss. 11.3 and 42.1 read on 2026-10-23 (consolidated to 2025-01-01); the edition question is open. ## Newfoundland and Labrador **Law.** Occupational Health and Safety Regulations, 2012, s. 2(x) (definition of TLV), s. 42 (hazardous substances) and s. 44 (thermal environment) [(Occupational Health and Safety Regulations, 2012 \[NL\], 2026, ss. 2, 42, 44)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-regulations-2012-nl). **What must be covered.** - **Basis of limits.** “TLV” means the ACGIH documentation “published annually or more frequently” (s. 2(x)), so the latest edition applies. Exposure is kept as low as reasonably practicable and never above an ACGIH TLV; ceiling, short-term and eight-hour limits apply “except as otherwise determined by the division”; excursions above an eight-hour limit are capped at three times for 30 minutes and five times at any time (s. 42(7)). - **Long shifts.** For work periods over eight hours in 24, the eight-hour exposure is adjusted as the ACGIH manual describes (s. 42(8)), in consultation with the committee or representative (s. 42(9)). - **Control program.** Monitoring and a chemical and biological control program (s. 42(1)-(4)). - **Heat and cold.** A thermal environment that is reasonable for the work “as established by the ACGIH” (s. 44(1)); monitoring equipment where the thermal environment may be hazardous (s. 44(2)); under unusually hot or cold conditions, further provisions such as regular monitoring, warning devices and additional first aid measures (s. 44(3)), with rest periods, drinks and medical supervision among the measures. **Fire-service nuance.** - Section 44(3) is the closest legal anchor for rehabilitation at fires and training. - Long-shift adjustments must be made with the committee, which suits a 24-hour schedule review. **Status.** Verified against the regulations consolidated to NLR 48/26 (read 2026-10-23), except the full s. 44(3) list. ## Yukon **Law.** Workplace Health Regulations (effective 1986), ss. 9 (thermal environment), 12 (heat stress) and 27 (air contaminants); Workplace Health and Safety Regulations, Part 11 ([Workplace Health Regulations \[YT\], 2026, ss. 9, 12, 27](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-workplace-health-regulations-yt); [Workplace Health and Safety Regulations \[YT\], 2022, ss. 11.05, 11.22](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-workplace-health-and-safety-regulations-yt)). **What must be covered.** - **Basis of limits.** Exposure to airborne contaminants is limited to the permissible concentrations in the regulation’s own air contaminant tables (s. 27(1)); mixtures are treated as additive (s. 27(2)); where exposure exceeds the permissible concentration, immediate steps to reduce it (s. 27(5)), with personal protective equipment only as a temporary measure (s. 27(6)). - **Long shifts.** Exposure to listed substances for more than eight hours in 24 is limited to a modified permissible concentration (s. 27(4)). - **Heat.** Where hot conditions may cause heat disorders, the employer determines and records a thermal index by WBGT or wet globe temperature (s. 12(1)); continuous work is not permitted above set limits, for example a WBGT of 30 °C for light, 28 °C for moderate and 26 °C for heavy work at low air velocity (s. 12(2)); above them, engineering controls, work-rest regimes, protective clothing or a combination (s. 12(3)); and wherever work is hot, instruction in the symptoms of heat disorders and an adequate supply of drinking water (s. 12(4)). - **Cold and general thermal conditions.** Indoor thermal conditions appropriate to the work, and outdoors or where uncontrollable, measures such as monitoring, shelters, heating or cooling equipment, clothing, drinks and acclimatization (s. 9). - **Firefighting.** The incident commander provides rest and rehabilitation, including food, drinks and a suitable thermal environment (s. 11.05); vehicle areas in fire halls are vented unless monitoring shows levels below the limits (s. 11.22). **Fire-service nuance.** - The 1986 tables are older than current ACGIH values for many substances; set monitor alarms to the lower of the two by policy. - Part 11 applies to volunteer firefighters in municipal service. **Status.** Partly verified: the Workers’ Safety and Compensation Board renderings read on 2026-10-23; the contaminant tables were not read. ## Northwest Territories **Law.** Occupational Health and Safety Regulations, s. 74 (thermal conditions) and Part 21 (s. 314 and Schedule O) [(Occupational Health and Safety Regulations \[NT\], 2024, ss. 74, 314, Sch. O)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-regulations-nt). **What must be covered.** - **Basis of limits.** Where a Schedule O substance is present, engineering controls to keep the contamination limit from being exceeded and steps so personal exposure does not exceed it (s. 314(1)). The territories keep their own table; Schedule O itself was not read. - **Long hours.** A written procedure, developed with the committee or representative, where workers regularly work more than eight hours a day or 40 hours a week, or face substances with similar effects (s. 314(2)-(3)). - **Heat and cold.** Indoor thermal conditions appropriate to the work and providing reasonable comfort (s. 74(1)); a measuring instrument where conditions may be a concern (s. 74(2)); outdoors or where conditions cannot be controlled, measures for protection and reasonable comfort (s. 74(3)); suitable clothing for unusual conditions (s. 74(4)). **Fire-service nuance.** - Cold is the dominant thermal hazard; the s. 74(3) duty supports warm-up shelters at winter incidents and rotation of crews. **Status.** Partly verified: ss. 74 and 314 read on 2026-10-23 (consolidated to 2024-09-26); Schedule O values not read. ## Nunavut **Law.** Occupational Health and Safety Regulations, s. 74 and Part 21 (s. 314, Schedule O), the same in substance and numbering as the Northwest Territories [(Occupational Health and Safety Regulations \[NU\], 2021, ss. 74, 314, Sch. O)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-occupational-health-and-safety-regulations-nu). **What must be covered.** - **Basis of limits and long hours.** As in the Northwest Territories: Schedule O contamination limits, and a written procedure where workers work more than eight hours a day or 40 hours a week (s. 314). - **Heat and cold.** The general thermal conditions duty (s. 74). **Fire-service nuance.** - Extreme cold warnings in parts of Nunavut are issued at much colder thresholds than in the south, so a department should set its own warm-up triggers rather than wait for a warning (Environment and Climate Change Canada, n.d.-a). **Status.** Partly verified: provisions checked against the Nunavut text through the research (consolidated to 2021-09-28); Schedule O not read. ## Federal **Law.** Canada Occupational Health and Safety Regulations, s. 10.19 (exposure limits) and, from 2027-01-30, s. 10.19.3 (thermal stress) added by SOR/2026-10 [(Canada Occupational Health and Safety Regulations \[CA\], 2026, ss. 10.19, 10.19.3)](https://thehumanfactor.ca/library/fire-service-safety/j22-exposure-limits-heat-and-cold-stress#ref-canada-occupational-health-and-safety-regulations-ca). **What must be covered.** - **Basis of limits.** No employee may be exposed to an airborne chemical agent, other than grain dust, flour dust and asbestos fibres, above the value adopted by ACGIH in its TLV and BEI publication “as amended from time to time” (s. 10.19(1)(a)); asbestos exposure as close to zero as possible and never above the ACGIH value (s. 10.19(1.1)); sampling by ACGIH, NIOSH or equivalent methods where a limit may be exceeded (s. 10.19(3)). - **Thermal stress, from 2027-01-30.** Procedures developed with the policy committee, work place committee or representative to reduce thermal stress, covering engineering controls, administrative controls (fluid replacement, work-rest cycles, acclimatization, physiological monitoring, scheduling), monitoring of humidity and wind speed, protective clothing, training in signs and symptoms, and recording of every thermal stress incident (s. 10.19.3(1)); implemented whenever conditions reach the ACGIH heat stress screening criteria or the ACGIH cold stress thresholds (s. 10.19.3(2)). - **Until then.** The employer’s general duty and hazard investigation apply to heat and cold. **Fire-service nuance.** - Airport and Department of National Defence fire services should build the s. 10.19.3 procedure before 2027-01-30 and record heat and cold incidents from then on. **Status.** Verified against the regulations consolidated to 2026-09-30, including the amendments not yet in force (read 2026-10-23). ## Chapters that rely on this topic **Front matter** - [00 Fire Service Safety Management System - Program HQ](https://thehumanfactor.ca/library/fire-service-safety/program-hq) **03 Assessment** - [02 Gap Assessment Tool](https://thehumanfactor.ca/library/fire-service-safety/gap-assessment-tool) **04 Policies** - [Policy - Facilities](https://thehumanfactor.ca/library/fire-service-safety/policy-facilities) - [Policy - Occupational Medical, Fitness and Wellness](https://thehumanfactor.ca/library/fire-service-safety/policy-occupational-medical-fitness-and-wellness) - [Policy - Personal Protective Equipment and Contamination Control](https://thehumanfactor.ca/library/fire-service-safety/policy-personal-protective-equipment-and-contamination-control) - [Policy - Respiratory Protection](https://thehumanfactor.ca/library/fire-service-safety/policy-respiratory-protection) **05 Programs** - [Airport Rescue and Firefighting Program](https://thehumanfactor.ca/library/fire-service-safety/airport-rescue-and-firefighting-program) - [Decontamination and Contamination Control Program](https://thehumanfactor.ca/library/fire-service-safety/decontamination-and-contamination-control-program) - [Facilities and Station Safety Program](https://thehumanfactor.ca/library/fire-service-safety/facilities-and-station-safety-program) - [Firefighter Rehabilitation Program](https://thehumanfactor.ca/library/fire-service-safety/firefighter-rehabilitation-program) - [Hazardous Materials, CBRN and Energy Hazards Program](https://thehumanfactor.ca/library/fire-service-safety/hazardous-materials-cbrn-and-energy-hazards-program) - [Hearing Conservation Program](https://thehumanfactor.ca/library/fire-service-safety/hearing-conservation-program) - [Heat, Cold and Weather Program](https://thehumanfactor.ca/library/fire-service-safety/heat-cold-and-weather-program) - [Infection Control and Medical Response Safety Program](https://thehumanfactor.ca/library/fire-service-safety/infection-control-and-medical-response-safety-program) - [Marine Firefighting Program](https://thehumanfactor.ca/library/fire-service-safety/marine-firefighting-program) - [Medical, Fitness and Wellness Program](https://thehumanfactor.ca/library/fire-service-safety/medical-fitness-and-wellness-program) - [Occupational Cancer Prevention, Exposure Tracking and Screening Program](https://thehumanfactor.ca/library/fire-service-safety/occupational-cancer-prevention-exposure-tracking-and-screening-program) - [Protective Clothing and Equipment Program](https://thehumanfactor.ca/library/fire-service-safety/protective-clothing-and-equipment-program) - [Respiratory Protection Program](https://thehumanfactor.ca/library/fire-service-safety/respiratory-protection-program) - [Wildland and Interface Program](https://thehumanfactor.ca/library/fire-service-safety/wildland-and-interface-program) **06 Safe Work Procedures** - [SWP - Bunker Gear Advanced and Specialized Cleaning and Repair](https://thehumanfactor.ca/library/fire-service-safety/swp-bunker-gear-advanced-and-specialized-cleaning-and-repair) - [SWP - Bunker Gear Routine Inspection and Cleaning](https://thehumanfactor.ca/library/fire-service-safety/swp-bunker-gear-routine-inspection-and-cleaning) - [SWP - Diesel Exhaust and Station Zoning](https://thehumanfactor.ca/library/fire-service-safety/swp-diesel-exhaust-and-station-zoning) - [SWP - On-Scene Preliminary Exposure Reduction](https://thehumanfactor.ca/library/fire-service-safety/swp-on-scene-preliminary-exposure-reduction) - [SWP - Post-Call Station Decontamination](https://thehumanfactor.ca/library/fire-service-safety/swp-post-call-station-decontamination) - [SWP - Rehabilitation at Incidents and Training](https://thehumanfactor.ca/library/fire-service-safety/swp-rehabilitation-at-incidents-and-training) - [SWP - Wildland Deployment, LCES and Heat](https://thehumanfactor.ca/library/fire-service-safety/swp-wildland-deployment-lces-and-heat) **07 Audit** - [02 Audit Checklist Master Index](https://thehumanfactor.ca/library/fire-service-safety/audit-checklist-master-index) - [Checklist - Cancer Prevention, Exposure and Screening](https://thehumanfactor.ca/library/fire-service-safety/checklist-cancer-prevention-exposure-and-screening) - [Checklist - Decontamination and Contamination Control](https://thehumanfactor.ca/library/fire-service-safety/checklist-decontamination-and-contamination-control) - [Checklist - Facilities and Station Safety](https://thehumanfactor.ca/library/fire-service-safety/checklist-facilities-and-station-safety) - [Checklist - Medical, Fitness and Wellness](https://thehumanfactor.ca/library/fire-service-safety/checklist-medical-fitness-and-wellness) - [Checklist - Rehabilitation](https://thehumanfactor.ca/library/fire-service-safety/checklist-rehabilitation) - [Checklist - Wildland, Heat and Weather](https://thehumanfactor.ca/library/fire-service-safety/checklist-wildland-heat-and-weather) **09 Forms and Templates** - [Form - Station Safety Inspection Checklist (Full)](https://thehumanfactor.ca/library/fire-service-safety/form-station-safety-inspection-checklist-full) ## Definitions - **Threshold limit value (TLV).** An airborne concentration or physical agent level, published by ACGIH, to which nearly all healthy workers may be exposed day after day without adverse effect; a jurisdiction makes it law by adopting it. - **Time-weighted average (TWA).** The average exposure over an eight-hour day or 40-hour week. - **Short-term exposure limit (STEL).** The limit for any 15-minute period, usually allowed no more than four times a shift. - **Ceiling.** A concentration that must never be exceeded. - **WBGT.** Wet bulb globe temperature, an index that combines air temperature, humidity, radiant heat and air movement, used to set heat stress work-rest cycles. - **Equivalent chill temperature.** The temperature that, without wind, would cool exposed skin as fast as the actual temperature and wind combined. ## References Association paritaire pour la santé et la sécurité du travail du secteur affaires municipales \[APSAM\]. (n.d.). *Sécurité incendie: généralités*. Canada Occupational Health and Safety Regulations, SOR/86-304 (Canada; consolidated to 2026-09-30). Control of Exposure to Biological or Chemical Agents, R.R.O. 1990, Reg. 833 (Ontario; consolidated to 2026-10-20). Environment and Climate Change Canada. (n.d.-a). *Criteria for public weather alerts*. General Regulation: Occupational Health and Safety Act, N.B. Reg. 91-191 (New Brunswick; consolidated to 2026-06-30). Government of Alberta. (n.d.-e). *OHS Code review*. National Fire Protection Association. (2025). *NFPA 1580, Standard for emergency responder occupational health and wellness* (consolidates NFPA 1581, 1582, 1583 and 1584). Occupational Health and Safety Act General Regulations, P.E.I. Reg. EC180/87 (Prince Edward Island; consolidated to 2025-01-01). Occupational Health and Safety Act, R.S.O. 1990, c. O.1 (Ontario; consolidated to 2026-10-20). Occupational Health and Safety Code, Alta. Reg. 191/2021 (Alberta; consolidated to 2025-03-31). Occupational Health and Safety Regulation, B.C. Reg. 296/97 (British Columbia; consolidated to 2026-10-20). Occupational Health and Safety Regulations, 2012, N.L.R. 5/12 (Newfoundland and Labrador; consolidated to 2026-10-07). Occupational Health and Safety Regulations, Nu. Reg. 003-2016 (Nunavut; consolidated to 2021-09-28). Occupational Health and Safety Regulations, N.W.T. Reg. 039-2015 (Northwest Territories; consolidated to 2024-09-26). Ontario Ministry of Labour, Immigration, Training and Skills Development \[MLITSD\]. (n.d.). *Firefighter guidance notes* (Section 21 Advisory Committee; individual notes revised to 2026). Regulation respecting occupational health and safety, CQLR c. S-2.1, r. 13 (Quebec; consolidated to 2026-07-01). The Occupational Health and Safety Regulations, 2020, R.R.S. c. S-15.1, Reg. 10 (Saskatchewan; consolidated to 2021-04-07). Workplace Health and Safety Regulations, N.S. Reg. 52/2013 (Nova Scotia; consolidated to 2025-09; amended to N.S. Reg. 163/2025). Workplace Health and Safety Regulations, Y.O.I.C. 2006/178 (Yukon; consolidated to 2022-09-30). Workplace Health Regulations, citation not recorded (Yukon; consolidation consulted in 2026, date not recorded). Workplace Safety and Health Regulation, Man. Reg. 217/2006 (Manitoba; consolidated to 2026-10-20). WorkSafeBC. (n.d.). *OHS guidelines, Part 31: Firefighting*.