Substance-Specific Issues

Carbon black, non respirable; classification of

Substance:

Carbon black; CAS No. 1333-86-4

Issue:

What [WHMIS] requirements do the Hazardous Products Act (HPA) and Controlled Products Regulations (CPR) place on a supplier of products containing greater than 0.1% w/w non respirable carbon black?

Background:

As opposed to referencing tests, the criteria for carcinogenicity specified in section 54 of the CPR for a pure substances and tested mixtures refer to lists by ACGIH and IARC. The criteria for untested mixtures in section 58 of the CPR cross-reference section 54.

IARC's "overall evaluation" states:

"Carbon black is possibly carcinogenic to humans (Group 2B)."

Appendix A, "Clarifications and Interpretations of the Hazard Communication Standard" to U.S. OSHA Directive CPL 2-2.38D, states:

"Any substance which is inextricably bound in a product is not covered under the HCS. For example, a hazard determination for a product containing crystalline silica may reveal that it is bound in a rubber elastomer and under normal conditions of use or during foreseeable emergencies cannot become airborne and, therefore, cannot present an inhalation hazard. In such a situation, the crystalline silica need not be indicated as a hazardous ingredient since it cannot result in employee exposure."

Conclusions:

As for non respirable crystalline silica.

Rationale:

As for non respirable crystalline silica.

References:

Canadian Centre for Occupational Health and Safety, "WHMIS Classification Workshop [February 22, 1988]", pages 110-112.

IARC Monographs on the Evaluation of Carcinogenic Risks to Humans; Volume 65, "Printing Processes and Printing Inks, Carbon Black and Some Nitro Compounds"; Carbon black [1333-86-4] (Vol. 65; 1996)

U.S. Dept. of Labor; OSHA Directives, CPL 2-2.38D - Inspection Procedures for the Hazard Communication Standard, 29 CFR 1910.1200, 1915.99, 1917.28, 1918.90, 1926.59, 1928.21; March 20, 1998; http://www.osha.gov/pls/oshaweb/owadisp.show_document? p_table=DIRECTIVES&p_id=1551 &p_text_version=FALSE

U.S. Dept. of Labor; OSHA Standard Interpretation and Compliance Letters; "Applicability of the HCS to crystalline silica when bound in a polymeric compound and silicone rubber elastomers"; February 8, 1989 letter from Thomas J. Shepich, Director, Directorate of Compliance Programs;http://www.osha.gov/pls/oshaweb/owadisp.show_document? p_table=INTERPRETATIONS&p_id=19746&p_text_version=FALSE