California Office of Environmental Health Hazard Assessment (OEHHA) has announced it intends to list three new chemicals to the Proposition 65 list of chemicals known to cause cancer.
The agency is proposing this action under the controversial “Labor Code” listing mechanism.
In its announcement, OEHHA said it has determined that N,N‑dimethylformamide, 2‑mercaptobenzothiazole, and tetrabromo- bisphenol A meet the criteria for listing by the labor code mechanism.
OEHHA made its determination to list the three chemical compounds based upon their inclusion in “Agents Classified by the IARC Monographs, Volumes 1 - 115(link is external)" (IARC, 2016). In this monograph IARC concludes that N,N‑dimethylformamide, 2 mercaptobenzothiazole, and tetrabromobisphenol A are classified in Group 2A (“probably carcinogenic to humans”), and that there is sufficient evidence of carcinogenicity in animals for N,N-dimethylformamide, 2 mercaptobenzothiazole, and tetrabromobisphenol A (Grosse et al., 2016(link is external)
The International Agency for Research on Cancer is one of the authoritative bodies recognized under Proposition 65.
N,N-dimethylformamide, also known as Dimethylformamide is a common solvent used to precipitate chemical reactions. Dimethylformamide is clear and odorless.
2-Mercaptobenzothiazole (MBT) is mainly used in the rubber industry as a vulcanization accelerator. It is also a rubber additive, but it has also other applications, such as floating gold from ore residue as part of the extraction process in certain mining operations.
Tetrabromobisphenol A (TBBPA) is used as a reactive flame retardant in epoxy, vinyl esters and polycarbonate resins. It is also used also as a flame retardant in polymers such as ABS, polystyrenes, phenolic resins, adhesives, paper, and textiles and others.