Methyl ethyl ketone (MEK)

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 ethyl ketone (MEK)

French name in the regulation: Méthyl éthyl cétone

CAS : 78-93-3

Exposure Standards in RROHS regulation

Permissible exposure values (PEV)

	ppm	mg/m³	f/cc	Notes
TWAEV	50	150	-	-
STEV	100	300	-	-
Ceiling	-	-	-	-

Carcinogenicity		Sensitizer
Simple asphyxiant		Percutaneous
Prohibited use		Prohibited recirculation
Minimum exposure		Explosion hazard
Ototoxic

TWA adjustment for unusual work schedules

1B : No adjustment

CNESST – Toxicological Index Service

Consult REPTOX file: Methyl ethyl ketone (MEK)

Analysis:

Méthyl éthyl cétone

Method: IRSST - 25-3

Sampling protocol

Sampling device:
Sampling media required:

#IRSST	Description
2190	Anasorb 747 140/70mg

Parameters:
Flow rate: Max: 0,2 L/min
TWA sampling volume: 10 L
STEL sampling volume: 3 L

Analytical protocol

Principle: Gas chromatography with flame ionization detection (GC-FID)
Precision (%): 3,4
Minimum reported value: 30 µg
Remarks: An activated charcoal tube 100/50 mg (#2120) may be used if the samples are refrigerated immediately after sampling of a maximum duration of 15 minutes. This alternative is recommended if other organic substances must be analyzed simultaneously on the same sample, only if the risk of underestimating the concentration of methyl ethyl ketone is assumed by the user. In this case the analytical uncertainty (Cva) is 4.4%. The analysis can be done by gas chromatography couple with mass spectrometry (CG-MS, IRSST method # 369); in this case the analytical uncertainty (Cva) is 4.5%.

Reference

IRSST. "Analyse de la méthyléthylcétone dans l'air". Méthode 25-3. Méthodes analytiques. Montréal: IRSST, 1995.