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.

Molybdenum [7439-98-7] (as Mo), Soluble compounds (Pr)  

French name in the regulation: Molybdène, Composés solubles (Pr)
CAS : 7439-98-7

Exposure Standards in RROHS regulation

Permissible exposure values (PEV)
ppm mg/m3 f/cc Notes
TWAEV - 0,5 - Pr
STEV - - - -
Ceiling - - - -
Carcinogenicity C3 Sensitizer
Simple asphyxiantPercutaneous
Prohibited useProhibited recirculation
Minimum exposureExplosion hazard
Ototoxic

TWA adjustment for unusual work schedules

1C : No adjustment

CNESST – Toxicological Index Service


Analysis:

Molybdène fraction respirable (exprimé en Mo), composés solubles

Recommended method by the IRSST:
Method: OSHA - ID121
Sampling device: Mixed cellulose ester filter
Parameters:
Flow rate: 1,7 (Nylon) 2,75 (GS3) L/min
TWA sampling volume: 360 L
STEL sampling volume: -
Remarks: A cyclone is required for sampling. The cassette to be used is directly related to the type of cyclone used. The GS3 cyclone model must be used with a 3 sections cassette. 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: Flame atomic absorption spectrophotometry (FAAS)
Remarks: This method allows the analysis of chemical elements present in the sample without distinguishing the different chemical forms. The analytical results are expressed as Molybdenum, respirable fraction.
OSHA Analytical Methods Manual. Method ID121. Metals & metalloid particulates in workplace atmosphere, 2002.