Methylene bis (4-cyclohexylisocyanate)

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.

Methylene bis (4-cyclohexylisocyanate)

French name in the regulation: Diisocyanate-4,4' de dicyclohexylméthane

CAS : 5124-30-1

Synonyms: Méthylène bis(4-cyclohexyl isocyanate)

Exposure Standards in RROHS regulation

Permissible exposure values (PEV)

	ppm	mg/m³	f/cc	Notes
TWAEV	0,005	0,054	-	-
STEV	-	-	-	-
Ceiling	-	-	-	-

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

TWA adjustment for unusual work schedules

III : Weekly adjustment

CNESST – Toxicological Index Service

Consult REPTOX file: Methylene bis (4-cyclohexylisocyanate)

Analysis:

Diisocyanate-4,4' de dicyclohexylméthane (HMDI)

Method: IRSST - 376

Sampling protocol

Sampling device:
Sampling media required:

#IRSST	Description
917	Impregnated GF filter in series with teflon filter and vial

Parameters:
Flow rate: 1 L/min
TWA sampling volume: 15 L
STEL sampling volume: -
Remarks: Refer to the sampling guidelines supplied with the equipment. HMDI must be sampled specifically.

Analytical protocol

Principle: High performance liquid chromatography with UV detection (HPLC-UV)
Precision (%): 11
Remarks: The two filters in the sampling cassette allow specific analysis of monomer HMDI in vapour form and in aerosol form. The result supplied in the report is the sum of the monomers of HMDI of the two fractions. Determination of the corresponding oligomers is also done during the analysis. The sampling time can be longer than 15 minutes if the HMDI is present in vapour form only. RMV for HMDI monomer vapour is 0.03 µg. RMV for HMDI monomer aerosol is 0.07 µg.

Reference

IRSST. "Détermination de la fraction monomèrique des isocyanates sous forme vapeur et aérosol dans l'air des lieux de travail". Méthode 376. Non publiée.

HMDI à haute sensibilité

Method: IRSST - 366

Sampling protocol

Sampling device:
Sampling media required:

#IRSST	Description
970	Impregnated GF filter

Parameters:
Flow rate: 1,0 L/min
TWA sampling volume: 15 L
STEL sampling volume: -
Remarks: The recommended volume is 15 litres; however the sampling time can be up to 8 hours. Store the samples in a refrigerator before and after sampling.

Analytical protocol

Principle: High performance liquid chromatography with mass spectrometry (HPLC-MS)
Precision (%): 4,9
Minimum reported value: 0,0015 µg
Remarks: HMDI must be specifically sampled. The analysis is done for the isocyanate present in vapour form only and the result is expressed as a monomer concentration.

Reference

IRSST. "Analyse des isocyanates à haute sensibilité". Méthode 366. Non publiée.