Proposed Registration Decision PRD2019-04, Bixafen and F9651-2 Fungicide

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Pest Management Regulatory Agency
21 May 2019
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2019-4E-PDF (PDF version)

This page is a summary of the consultation document. If you would like to comment, please request the full consultation document.

To obtain a full copy of Proposed Registration Decision PRD2019-04, Bixafen and F9651-2 Fungicide please contact our publications office.

Should you require further information please contact the Pest Management Information Service.

Summary

Table of Contents

Proposed Registration Decision for Bixafen and F9651-2 Fungicide

Health Canada’s Pest Management Regulatory Agency (PMRA), under the authority of the Pest Control Products Act, is proposing registration for the sale and use of Bixafen (F9650) Technical Fungicide, containing the technical grade active ingredient bixafen, and F9651-2 Fungicide, containing the technical grade active ingredients bixafen and tebuconazole, to control foliar diseases on wheat, barley, oats and soybean.
Tebuconazole is currently registered in Canada for foliar and seed treatment uses on wheat, barley, oats, corn, and soybean, as well as use on turf and for industrial uses as a wood preservative. All diseases proposed on the F9651-2 Fungicide label for cereal crops and two diseases proposed for soybean are currently registered for tebuconazole at the rates proposed for F9651-2 Fungicide.

An evaluation of available scientific information found that, under the approved conditions of use, the health and environmental risks and the value of the pest control products are acceptable.

This summary describes the key points of the evaluation, while the Science Evaluation of Proposed Registration Decision PRD2019-04, Bixafen and F9651-2 Fungicide provides detailed technical information on the human health, environmental and value assessments of bixafen and F9651-2 Fungicide.

What Does Health Canada Consider When Making a Registration Decision?

The key objective of the Pest Control Products Act is to prevent unacceptable risks to people and the environment from the use of pest control products. Health or environmental risk is considered acceptable if there is reasonable certainty that no harm to human health, future generations or the environment will result from use or exposure to the product under its proposed conditions of registration. The Pest Control Products Act also requires that products have value when used according to the label directions. Conditions of registration may include special precautionary measures on the product label to further reduce risk.

To reach its decisions, the PMRA applies modern, rigorous risk-assessment methods and policies. These methods consider the unique characteristics of sensitive subpopulations in humans (for example, children) as well as organisms in the environment. These methods and policies also consider the nature of the effects observed and the uncertainties when predicting the impact of pesticides. For more information, please refer to the following:

Before making a final registration decision on bixafen and F9651-2 Fungicide, Health Canada’s PMRA will consider any comments received from the public in response to PRD2019-04. Health Canada will then publish a Registration Decisionon bixafen and F9651-2 Fungicide, which will include the decision, the reasons for it, a summary of comments received on the proposed registration decision and Health Canada’s response to these comments.

For more details on the information presented in this summary, please refer to the Science Evaluation of PRD2019-04.

What Is Bixafen?

Bixafen is classified as a Group 7 fungicide which inhibits an enzyme involved in energy production in fungi and contributes to the management of diseases of cereals and soybean.

Health Considerations

Can Approved Uses of Bixafen Affect Human Health?

F9651-2 Fungicide, containing bixafen, is unlikely to affect your health when used according to label directions.

Potential exposure to bixafen may occur through the diet (food and water) or when handling and applying the product. When assessing health risks, two key factors are considered:

  • the levels where no health effects occur and
  • the levels to which people may be exposed.

The dose levels used to assess risks are established to protect the most sensitive human population (for example, children and nursing mothers). As such, sex and gender are taken into account in the risk assessment. Only uses for which the exposure is well below levels that cause no effects in animal testing are considered acceptable for registration.

Toxicology studies in laboratory animals describe potential health effects from varying levels of exposure to a chemical and identify the dose where no effects are observed. The health effects noted in animals occur at doses more than 100-times higher (and often much higher) than levels to which humans are normally exposed when using pesticide products according to label directions.

In laboratory animals, the technical grade active ingredient bixafen was of low acute toxicity by the oral, dermal and inhalation routes. Bixafen was minimally irritating to the eyes and non-irritating to the skin, and did not cause an allergic skin reaction; consequently, no hazard signal words are required on the label.

The end-use product F9651-2, containing bixafen and tebuconazole, was of moderate acute toxicity via the oral route; consequently, the hazard signal words “WARNING POISON” are required on the label. It was of low toxicity via the dermal and inhalation routes of exposure. It was non-irritating to the eyes and skin and did not cause an allergic skin reaction.

Registrant-supplied short- and long-term (lifetime) animal toxicity tests were assessed for the potential of bixafen to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. The most sensitive endpoints used for risk assessment included effects on body weight, the liver and thyroid gland, and blood coagulation. There is low concern for increased susceptibility of the young exposed to bixafen. The risk assessment protects against these and any other potential effects by ensuring that the level of exposure to humans is well below the lowest dose at which these effects occurred in animal tests.

Residues in Water and Food

Dietary risks from food and drinking water have been determined to be acceptable.

Aggregate dietary intake estimates (food plus drinking water) revealed that the general population and children 1–2 years old, the subpopulation which would ingest the most bixafen relative to body weight, are expected to be exposed to less than 33% of the acceptable daily intake. Based on these estimates, the chronic dietary risk from bixafen is not of health concern for all population subgroups.

Acute dietary (food plus drinking water) intake estimates for the general population and all population subgroups were less than 15% of the acute reference dose, and are not of health concern. The highest exposed subpopulation was children 1–2 years old.

The Food and Drugs Act prohibits the sale of adulterated food, that is, food containing a pesticide residue that exceeds the established maximum residue limit (MRL). Pesticide MRLs are established for Food and Drugs Act purposes through the evaluation of scientific data under the Pest Control Products Act. Food containing a pesticide residue that does not exceed the established MRL does not pose an unacceptable health risk.

Residue trials conducted throughout the United States and Canada using bixafen on wheat, field corn, sweet corn, sorghum, carrots, radishes, sugar beets, potatoes, soybeans and peanuts, and throughout the European Union on barley are acceptable. The MRLs for this active ingredient can be found in the Science Evaluation of PRD2019-04.

New MRLs are not proposed for tebuconazole given that adequate MRLs are currently established for tebuconazole on all proposed crops.

Occupational Risks from Handling F9651-2 Fungicide

Occupational risks have been determined to be acceptable when bixafen is used according to the label directions, which include protective measures.

Farmers and custom applicators who mix, load or apply F9651-2 Fungicide, as well as field workers entering freshly treated fields of wheat (spring, durum and winter), barley, oats and soybeans, can come in direct contact with bixafen residues on the skin. Therefore, the label specifies that handlers mixing/loading and applying F9651-2 Fungicide must wear long-sleeved shirt, long pants, chemical-resistant gloves and shoes plus socks (gloves are not required inside a closed cab or cockpit). The label also requires that workers do not enter treated fields of wheat (spring, durum and winter), barley, oats and soybeans for 12 hours after application.

Taking into consideration these label statements, the number of applications and the expectation of the exposure period for handlers and workers, the health risk to these individuals are not of concern.

Potential for bystander exposure is considered minimal and is expected to be significantly less than exposure estimated for workers. Based on the worker assessment, bystander exposure is not of concern.

F9651-2 Fungicide is co-formulated with tebuconazole. Tebuconazole is already registered for use in Canada.

Environmental Considerations

What Happens When Bixafen Is Introduced Into the Environment?

When bixafen is used according to the label directions, the risks to the environment have been determined to be acceptable.

Bixafen enters the environment when applied to control foliar diseases of cereal crops and soybeans caused by fungi. On land, bixafen is slow to break down and is not expected to move through the soil and reach groundwater. In water bodies, bixafen will move to sediments where it will remain over time. Bixafen is not expected to be found in the air, or to travel long distances from where it was applied. Bixafen is not expected to build-up in the tissues of organisms.

Bixafen presents negligible risk to wild mammals, birds, bees, beneficial insects, earthworms, invertebrates, marine algae, or aquatic plants. When bixafen is used at labelled application rates, it may pose risks of concern to freshwater diatoms/algae, freshwater fish, amphibians, and terrestrial plants. Therefore, mitigation measures, such as spray buffer zones, are required to minimize potential exposure to organisms in freshwater habitats and non-target terrestrial plants. When bixafen is used in accordance with the label and the required risk reduction measures are applied, the reduced environmental exposure is deemed adequate and risks are considered to be acceptable.

Value Considerations

What Is the Value of F9651-2 Fungicide?

F9651-2 Fungicide contains a combination of active ingredients with different modes of action to control concurrent diseases and manage the development of pathogen resistance.

Both bixafen and tebuconazole have particular strengths against certain diseases which are enhanced by the contribution of the other. The combination of these two active ingredients will control different diseases that co-occur while eliminating the need for tank mixing. F9651-2 Fungicide is an additional fungicide option for cereal and soybean growers that can be used to manage diseases in their crops.

Measures to Minimize Risk

Labels of registered pesticide products include specific instructions for use. Directions include risk-reduction measures to protect human and environmental health. These directions must be followed by law.

The key risk-reduction measures being proposed on the label of Bixafen (F9650) Technical Fungicide and F9651-2 Fungicide to address the potential risks identified in this assessment are as follows:

Key Risk-Reduction Measures

Human Health

Because there is a concern with users coming into direct contact with bixafen on the skin or through inhalation of spray mists, anyone mixing, loading and applying F9651-2 Fungicide must wear long-sleeved shirt, long pants, chemical-resistant gloves and shoes plus socks (gloves are not required inside a closed cab or cockpit). The label also requires that workers do not enter treated fields of wheat (spring, durum and winter), barley, oats and soybeans for 12 hours after application. In addition, standard label statements to protect against drift during application are present on the label.

Environment

To minimize exposure and reduce risks to freshwater diatoms/algae, freshwater fish, amphibians, and terrestrial plants, spray buffer zones and precautionary label statements are required. Using vegetative filter strips may also help to reduce contamination of water bodies.

Next Steps

Before making a final registration decision on bixafen and F9651-2 Fungicide, Health Canada’s PMRA will consider any comments received from the public in response to PRD2019-04. Health Canada will accept written comments on PRD2019-04 up to 45 days from the date of its publication. Please note that, to comply with Canada’s international trade obligations, consultation on the proposed MRLs will also be conducted internationally via a notification to the World Trade Organization.

Please forward all comments to Publications. Health Canada will then publish a Registration Decision, which will include its decision, the reasons for it, a summary of comments received on the proposed decision and Health Canada’s response to these comments.

Other Information

When the Health Canada makes its registration decision, it will publish a Registration Decision on bixafen and F9651-2 Fungicide (based on the Science Evaluation of PRD2019-04). In addition, the test data referenced in PRD2019-04 will be available for public inspection, upon application, in the PMRA’s Reading Room (located in Ottawa).

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