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Canada - Final Regulatory Action
Benzidine CAS number:
92-87-5
Date circular:
12/06/2005

Chemical name: [1,1'-Biphenyl]-4,4'-diamine

Final regulatory action has been taken for the category: Industrial

Final regulatory action: The chemical is Severely Restricted

Use or uses prohibited by the final regulatory action:

The Prohibition of Certain Toxic Substances Regulations, 2003 prohibit the manufacture, use, sell, offer for sale or import of benzidine and bezidine dihydrochloride, with the exceptions listed below.

Use or uses that remain allowed:

The Prohibition o/Certain Toxic Substances Regulations, 2003, do not apply in respect of the use of benzidine or benzidine dihydrochloride:
in a laboratory for scientific research,
as a laboratory analytical standard, or
in the following permitted uses:
staining for microscopic examination, such as immunoperoxidase staining, histochemical staining or cytochemical staining
reagent for detecting blood in biological fluids
niacin test to detect some microorganisms
reagent for detecting chloralhydrate in biological fluids.
The Regulations also do not apply in respect of the manufacture, sale, offering for sale or import of benzidine or benzidine dihydrochloride for those uses.

The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

The Prohibition of Certain Toxic Substances Regulations, 2003 prohibit the manufacture, use, sale, offer for sale and import of certain toxic substances. The Regulations exempt some uses from this prohibition, which can vary from substance to substance (more detail is
provided in section 2.5 of this notification).

The reasons for the final regulatory action were relevant to: Human health

Summary of known hazards and risks to human health:

Benzidine has been shown to cause cancer in occupationally exposed workers and experimental animals and is considered to be a "non-threshold toxicant" (i.e., a substance for which there is believed to be some chance of adverse effect at any level of exposure).
Note: Benzidine dihydrochloride is also being addressed in the Regulations because it dissociates in water into benzidine.
REFERENCE
Canadian Environmental Protection Act Priority Substances List Assessment Report: Benzidine

Expected effect of the final regulatory action in relation to human health:

Levels of use of benzidine and benzidine dihydrochloride in Canada at the time the Regulations were published did not pose a threat to human health and the environment. The Regulations were put in place as a precautionary measure to protect the health of Canadians and ecosystems by ensuring that future production, importation and use of benzidine and benzidine dihydrochloride is prohibited with very limited exemptions.

Date of entry into force of the final regulatory action: 20/03/2003