Canada to re-evaluate two pesticides

The Canadian Pest Management Regulatory Agency (PMRA) plans to re-evaluate registrations of the plant growth regulator, paclobutrazol and the herbicide, isoxaben. The proposed re-evaluation decisions for these two pesticides are anticipated to be published for consultation by winter 2013.

The PMRA's pesticide re-evaluation program considers potential risks as well as the value of pesticide products to ensure they continue to meet standards of modern science and current policy established to protect human health and the environment. Reviews of these two active ingredients’ toxicology were conducted in support of the initial registration and the toxicology databases for them are considered complete. Based on the registered use pattern for them, dietary exposure assessments are not required. Environmental exposure to paclobutrazol is expected to be limited. For isoxaben, buffer zones for the protection of sensitive terrestrial and aquatic habitats will be calculated based on current practices.

Paclobutrazol is a plant growth regulator that has been registered in Canada since 1995. Paclobutrazol is currently registered for use on Greenhouse Non-Food Crops (Use-site Category 6). All registered paclobutrazol end-use products are formulated as liquids, to be applied either by drench application or by hand-held spray equipment.

Isoxaben is a selective pre-emergence herbicide that has been registered in Canada since 1995. Isoxaben is currently registered for uses under the Use-site Category 27, Ornamental Outdoors, to control certain broadleaved weeds. There is currently one registered isoxaben end-use product formulated as a granular formulation, which is applied by low-pressure ground spray equipment.