The Canadian government has added five methylenediphenyl diisocyanates (MDIs) substances to schedule 1 of the Canadian Environmental Protection Act, 1999 (Cepa) – its list of toxic substances. Their addition means the country can act to impose regulations to address identified risks.
The order, which took effect on 15 May, applies to:
- Benzene, 1,1′-methylenebis [4-isocyanato- (4,4′-MDI)
- Benzene, 1,1′-methylenebis [2-isocyanato- (2,2′-MDI)
- Benzene, 1-isocyanato-2-[(4-isocyanatophenyl) methyl]- (2,4′-MDI)
- Benzene, 1,1′-methylenebis [isocyanato- (mixed MDI)
- Isocyanic acid, polymethylenepolyphenylene ester (pMDI)
The move finalizes a proposal issued in 2017 on the heels of a final screening assessment that found the MDIs present health concerns including cancer, respiratory problems, and skin sensitization. The government concluded that they must meet at least one human health criterion for a toxic substance, as defined under section 64 of Cepa.
Since then, it has floated a ‘code of practice’, aimed at reducing exposure to the substances from particular spray polyurethane foam (SPF) products. Comments will be accepted on this proposal until 5 June.
Outside of SPF applications, the substances are also used in elastomers, coatings, adhesives, and sealants, as well as in particleboard and other wood products.