In the Summer, 1998 edition of LIAISON, CCOHS brought to your attention a WHMIS Policy Issue Sheet regarding ACGIH carcinogens. The tripartite WHMIS Current Issues Committee had resolved that the Controlled Products Regulations (CPR) should be revised to include chemicals classified as A3 (animal carcinogens) by the American Conference of Governmental Industrial Hygienists. This change was not gazetted in the Canada Gazette, but was published in a Current Issues Committee Policy Issue Sheet (No. 72(b)).

As a result of the guidance contained in this Policy Issue Sheet, followed by discussions with Health Canada, CCOHS amended the proposed WHMIS classifications for ten chemicals in the CHEMINFO database. Recently, Health Canada clarified that "if a controlled product does not otherwise fall within any other Class D criteria specified in the CPR, a supplier would not be legally obliged to depict the symbol corresponding to Division 2 of Class D (i.e., the stylized "T") on the sole basis that it is included in ACGIH A3. However, regarding MSDS disclosure, suppliers should refer to WHMIS Information Bulletin No. 12 and the Product Safety Reference Manual available from Health Canada".

Based on this clarification, CCOHS has again reviewed the carcinogenicity data for the ten chemicals in question. In all cases, it has been concluded that there is insufficient information to classify these chemicals as WHMIS carcinogens. Consequently, CCOHS has revised the affected records to remove the carcinogenicity classification. The CCOHS CHEMINFO reviews still disclose that these chemicals have been designated A3 (animal carcinogens) by ACGIH.

The ACGIH A3 carcinogenicity designation is specifically assigned to chemicals that are carcinogenic in animals under conditions that may not be relevant to worker exposure (for example, at relatively high doses or by non-relevant routes of exposure). In most cases, assigning a carcinogenicity classification exclusively based on the A3 designation was considered overly conservative. For additional information, consult the CHEMINFO database records for these chemicals.

Update on Xylene and WHMIS

The WHMIS Enforcement Issues Subcommittee consists of thirteen governmental Canadian agencies responsible for occupational safety and health, including the administration of the WHMIS compliance program. On behalf of this committee, Health Canada recently (January 26, 1999) issued a letter regarding MSDSs and labels for products that contain xylene.

Several Canadian regulatory authorities including Health Canada have concluded that xylene meets the criteria for Section 53 (Teratogenicity and Embryotoxicity) of the Controlled Products Regulations, resulting in a classification of D2A. This classification is based on animal evidence of developmental toxicity that was observed in the absence of maternal toxicity.

The Hazardous Products Act and the Controlled Products Regulations DO NOT require the disclosure of WHMIS class(es), division(s) nor subdivision(s) on the product label or MSDS. However, if a supplier/importer has disclosed the WHMIS classification on the MSDS and/or label, the WHMIS Enforcement Issues Subcommittee has stated that it is unacceptable that the supplier/importer not also disclose D2A. Importers and suppliers of products containing xylene have been asked to comply with this request within 90 days from January 26, 1999.

CCOHS has classified xylene as fetotoxic based on observations of reduced weight, delayed ossification of the skull and behavioural effects in the offspring of rats exposed by inhalation to 500 ppm xylene. These fetotoxic effects were observed in the absence of maternal toxicity. For additional information, consult the CHEMINFO database record for xylene (mixed isomers).

The following chemicals are no longer classified as WHMIS carcinogens in the CHEMINFO database:

aniline, bromoform, chlorobenzene, chrysene*, ethyl chloride,hydrogen peroxide, hydroquinone, methyl tert-butyl ether, 1,1,2,2,-tetrachloroethane and trichloroacetic acid.

*Even though chrysene does not specifically meet the WHMIS carcinogenicity criteria, CCOHS scientific staff recommend that chrysene be handled as a possible carcinogen. Chrysene seldom occurs naturally on its own. Rather, it is part of complex mixtures of polycylic aromatic hydrocarbons, some of which are known carcinogens.

The WHMIS Information Bulletin Issue No. 12 can be obtained via the internet at http://www.hc-sc.gc.ca/ehp/ehd/catalogue/psb_pubs/whmis12.htm