Health Canada PMRA Proposes Chlorothalonil Cancellation

by WCTA Staff

On February 10, 2022, Canada’s Pest Management Regulatory Authority, a branch of Health Canada in charge of registering and continuously evaluating the safety and efficacy of  pesticides used in Canada, circulated a proposed re-evaluation decision (PRED) for the popular turf fungicide active ingredient, chlorothalonil.

Section 6.0 of the 60 page document states:

“Under the authority of the Pest Control Products Act and based on an evaluation of available relevant scientific information related to the aspects of concern for human health and the environment, Health Canada is proposing continued registration of greenhouse ornamental uses of chlorothalonil and associated end-use products registered for sale and use in Canada.  All other uses of chlorothalonil are proposed for cancellation since potential risks to human health and the environment were not shown to be acceptable when products are used according to the current conditions of registration.”

Uses of chlorothalonil in Canada

Chlorothalonil is a contact and protectant fungicide with a multi-site mode of action. It controls a broad range of fungal diseases on a large number of field and orchard crops, conifers, greenhouse celery seedbeds, greenhouse ornamentals, outdoor ornamentals, mushroom houses, and turf (golf courses and sod farms). 

Chlorothalonil is applied by both aerial and ground application equipment.  All registered pest control products containing chlorothalonil used in agriculture, horticulture and turf, are considered for the special review.  Chlorothalonil is also used as a dry-film material preservative agent against bacterial and fungi contamination or spoilage of paint and is currently under re-evaluation in Canada however this use is not part of the scope of this special review.

The PMRA initiated the special review of chlorothalonil in 2018 based on information reported under section 13 of the Pest Control Products Act and information from the 2016 European Food Safety Authority.  Subsequent to the initiation of the special review, PMRA became aware of the European Union (EU) decision to prohibit all uses of chlorothalonil as plant protection products due to human health and environmental concerns.  

Concerns over chlorothalonil include potential exposure to metabolites from groundwater, potential carcinogenicity related to dietary exposure, potential genotoxicity of chlorothalonil metabolites (related to the health hazard), potential risk to non-target amphibians and fish, transportation in runoff, environmental toxicity, and several others.

Next steps

Before making a special review decision on the agricultural, horticultural and turf uses of chlorothalonil, Health Canada will consider all comments received from the public in response to this consultation document. A science-based approach will be applied in making a final decision on chlorothalonil.  Health Canada will then publish a special review decision document, which will include the decision, the reasons for it, a summary of the comments received on the proposed decision, and Health Canada’s response to these comments.

The full document can be found on Health Canada’s website by clicking here.