IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

According to Decree 280-2024 published on February 28, 2024, in the Gazette officielle du Québec, the amendment to the Appendix 1 of the Regulation respecting occupational health and safety (RSST, RLRQ, c. S-2.1, r. 13) will come into force on March 14, 2024. These regulatory changes have not yet been incorporated into the current Substance Data Sheets of the Sampling Guide for Air Contaminants in the Workplace. An update is currently underway and will be available as soon as possible. Consequently, the information contained in the data sheets of substances modified or added in Decree 280-2024 is partially inaccurate or incomplete. Please consult our infoLABO (in French only) for more details. Please contact our client service: [email protected] for further information.

Methyl chloride

French name in the regulation: Chlorométhane
CAS : 74-87-3

Exposure Standards in RROHS regulation

Permissible exposure values (PEV)
ppm mg/m3 f/cc Notes
TWAEV 50 103 - -
STEV 100 207 - -
Ceiling - - - -
Simple asphyxiant Percutaneous
Minimum exposure Sensitizer
Prohibited use Prohibited recirculation
Carcinogenicity

TWA adjustment for unusual work schedules

IV : Daily or weekly adjustment ( the more stringent of the two)

CNESST – Toxicological Index Service

Consult REPTOX file: Methyl chloride

Analysis:

Chlorométhane

Recommended method by the IRSST:
Method: NIOSH - 1001
Sampling device: Two 100/50 mg activated charcoal tubes in series
Parameters:
Flow rate: 0,01-0,1 L/min
TWA sampling volume: 3 L
STEL sampling volume: 1,5 L
Remarks: This substance is not analyzed by our laboratories. It might be possible that the analysis be performed by another laboratory. Please contact the IRSST before sampling.
Principle: Gas chromatography with flame ionization detection (GC-FID)
NIOSH Manual of Analytical Methods, 4th ed., Method 1001 : Methyl Chloride, 1994.
Following the amendment of Appendix 1 of the Quebec Regulation respecting occupational health and safety (RSST, RLRQ, c. S-2.1, r. 13), part of Quebec Occupational Health and Safety Act, which came into effect on March 26, 2020, the TWAEV, STEL and Ceiling values for certain substances are now expressed in ppm. For these substances, the IRSST performed the conversion calculations to express these TWAEV, TWA and Ceiling values in mg/m3, which thus appears in its Sampling Guide for Air Contaminants in the Workplace (Guide d'échantillonnage des contaminants de l'air en milieu de travail ) and the associated Substance Data Sheets. However, it is imperative to refer to the values expressed in the RSST which are legally binding.