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Canada - Final Regulatory Action
Alachlor CAS number:
Date circular:

Chemical name: Acetamide, 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-

Final regulatory action has been taken for the category: Pesticide

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action:

All uses and formulations are prohibited.

Pesticide use or uses that remain allowed:


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

Summary of the final regulatory action:

all uses banned Dec 31, 1985; low import tolerances set for corn, soybean, drybeans, meat and milk (1).
all product registrations cancelled due to carcinogenic potential, and existence of a lower risk alternative product, metolachlor (2).
manufacturer (Monsanto) requested review of regulatory action, as allowed by section 23 of PCPA. Alachlor Review Board formed Nov 13, 1985 (2).
final report (October 1987), Board recommended restoration of alachlor registrations, believing that the relative safety of the alternative product metalochlor did not support cancellation of alachlor registrations. (2).
the Minister maintained metolachlor safer than alachlor and ban upheld (3)

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

Summary of known hazards and risks to human health:

Two long-term dietary studies in the rat, indicated an increase in the incidence of adenomas and adenocarcinomas in the nasal turbinates, and of stomach tumours at a number of doses (2).
A long-term dietary mouse study indicated a statistically significant number of lung tumours in females at the highest dose (2).
Based on the above results alachlor was deemed an animal carcinogen with potential as a human carcinogen (2)
The primary concern was occupational exposure but the presence of alachlor in ground water, with further potential of contamination, increased concerns of exposure (2)
Determined that use of alachlor represents an unacceptable risk of harm to public health (1)

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

Elimination of herbicide use of alachlor in Canada, thus eliminating hazard due to occupational exposure and exposure through contaminated ground water.
At the time, some costs to farmers were expected due to virtual monopoly for Ciba-Geigy and a decrease in performance in certain instances however due to the continued presence of metolachlor these effects are expected to be relatively minor.
No further effect anticipated as action was taken several years ago.

Date of entry into force of the final regulatory action: 31/12/1985