Proposed Registration Decision PRD2022-04, Pyraziflumid and Parade Fungicide

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Pest Management Regulatory Agency
28 February 2022
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2022-4E-PDF (PDF version)

Summary

Table of contents

• Proposed registration decision for pyraziflumid
• What does Health Canada consider when making a registration decision?
• What is pyraziflumid?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
• Next steps
• Other information

Proposed registration decision for pyraziflumid

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 Pyraziflumid Technical and Parade Fungicide, containing the technical grade active ingredient pyraziflumid, to control powdery mildew and scab on apples.

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 PRD2022-04, Pyraziflumid and Parade Fungicide provides detailed technical information on the human health, environmental and value assessments of pyraziflumid and Parade 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^{Footnote 1} 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 Act also requires that products have value^{Footnote 2} 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:

• Protecting Your Health and the Environment
• Pesticide Registration Process
• Pesticide Risk Reduction Program.

Before making a final registration decision on pyraziflumid and Parade Fungicide, Health Canada’s PMRA will consider any comments received from the public in response to this consultation document.^{Footnote 3} Health Canada will then publish a Registration Decision^{Footnote 4} on pyraziflumid and Parade 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 PRD2022-04.

What is pyraziflumid?

Pyraziflumid is a new conventional fungicide active ingredient that controls certain economically important diseases of apples.

Health considerations

Can approved uses of pyraziflumid affect human health?

Parade fungicide, containing pyraziflumid, is unlikely to affect your health when used according to proposed label directions.

Potential exposure to pyraziflumid may occur through the diet (food and drinking water), when handling and applying the end-use product, or when coming into contact with treated surfaces. When assessing health risks, two key factors are considered: the levels at which 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 level at which 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 pesticide products are used according to label directions.

In laboratory animals, pyraziflumid was of low acute toxicity via the oral, dermal and inhalation routes. It was non-irritating to the eyes and skin. It did not cause an allergic skin reaction.

The acute toxicity of Parade Fungicide, containing pyraziflumid, was low via the oral, dermal and inhalation routes of exposure. Parade Fungicide was non-irritating to the eyes and skin, but caused an allergic skin reaction. Consequently, the hazard statement “POTENTIAL SKIN SENSITIZER” is required on the label.

Registrant-supplied short- and long-term (lifetime) animal toxicity tests, as well as information from the published scientific literature, were assessed for the potential of pyraziflumid to cause neurotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. The most sensitive endpoints for risk assessment were effects on the liver and thyroid, changes in motor activity level, and abortions. There was no evidence to suggest that pyraziflumid damaged genetic material. Pyraziflumid did, however, cause thyroid tumours in male rats at the highest dose level tested. An increase in lung tumours observed in mice could not clearly be attributed to treatment with pyraziflumid. Liver tumours observed in female rats at the highest dose level tested, which exceeded the maximum tolerable dose, are not relevant to human health risk assessment. There was no evidence of increased sensitivity of the young compared to adult animals. The risk assessment protects against the effects noted above and other potential effects by ensuring that the level of exposure to humans is well below the lowest dose level at which these effects occurred in animal tests.

Residues in water and food

Dietary risks from food and drinking water are not of health concern.

Aggregate acute dietary (food plus drinking water) intake estimates for the general population and all population subgroups are expected to be less than or equal to 3% of the acute reference dose, and are not of health concern. Children 1–2 years old are the subpopulation expected to be subject to the highest exposure relative to body weight.

Aggregate chronic dietary (food plus drinking water) intake estimates for the general population and all population subgroups are expected to be less than 30%of the acceptable daily intake, and are not of health concern. Infants are the subpopulation expected to be subjected to the highest exposure relative to body weight.

On the strength of the overall information, it was determined that a threshold approach was appropriate for the cancer risk assessment based on the observed tumours. Overall, the endpoints selected for the non-cancer dietary risk assessment are considered protective of potential cancer risks.

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. Given that dietary risks from the consumption of foods are shown to be acceptable when pyraziflumid is used according to the supported label directions, MRLs are being proposed as a result of this assessment (refer to PMRL2022-02, Pyraziflumid).

MRLs for pyraziflumid determined from acceptable residue trials conducted in the United States, including growing regions representative of Canada, on various crops can be found in the Science Evaluation section of PRD2022-04.

Occupational risks from handling Parade Fungicide

Occupational risks are not of health concern when Parade Fungicideis used according to the proposed label directions, which include protective measures.

Workers mixing, loading or applying Parade Fungicide, and workers entering recently treated apple orchards can come in direct contact with pyraziflumid residues on the skin and through inhalation. Therefore, the label specifies that anyone mixing, loading and applying Parade Fungicide must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. Chemical-resistant gloves are not required during application within a closed cab. The label also requires that workers do not enter or be allowed into treated areas during the restricted-entry interval (REI) of 12 hours. Taking into consideration the label statements, the number of applications and the duration of exposure for handlers and postapplication workers, the risks to these individuals are not of health concern.

Health risks in residential and other non-occupational environments

Risks in residential and other non-occupational environments are not of health concern when Parade Fungicide is used according to the proposed label directions and restricted-entry intervals are observed.

Adults, youth and children involved in postapplication activities, such as pruning and hand harvesting, may come in direct contact with pyraziflumid residues on the skin when apple trees in residential areas are treated with Parade Fungicide by commercial applicators. Taking into consideration the label statements, the number of applications and the duration of exposure, the risks to homeowners and their family are not of health concern once the sprays have dried.

Non-occupational exposure during pick-your-own fruit activities in treated orchards are also not of health concern since the postapplication occupational risk assessment, which represents a more conservative exposure scenario, demonstrates that there are no health risks of concern associated with dermal exposure to the patrons in a pick-your-own facility.

Aggregate health risks

When apple trees in residential settings or pick-your-own facilities are treated with Parade Fungicide, there is potential for individuals to be exposed to pyraziflumid via the dermal and oral routes of exposure concurrently. As such, aggregation of dermal and dietary exposure was assessed and no health risks of concern were identified.

Health risks to bystanders

Bystander risks are not of health concern when Parade Fungicideis used according to the proposed label directions and spray drift restrictions are observed.
A standard label statement to protect against drift during application is on the label. Therefore, health risks to bystanders are not of concern.

Environmental considerations

What happens when pyraziflumid is introduced into the environment?

When used according to label directions, risks associated with the use of pyraziflumid and its associated end-use product have been determined to be acceptable from the viewpoint of environmental protection.

Pyraziflumid can enter the environment through spray drift deposition or run-off when applied as a foliar spray to control fungal diseases on apples. When released into the terrestrial and aquatic systems, pyraziflumid primarily resides in the soil or sediment and can remain there for months or years, depending on the soil and sediment types and conditions. It does not break down easily, and when it does, it produces a few smaller molecules at very low levels. Pyraziflumid is expected to be taken up by plants and move inside the plants. Pyraziflumid has a potential to move through the soil and, therefore, may reach groundwater. Pyraziflumid is not expected to be found in air or travel long distances in the atmosphere from where it is applied. Pyraziflumid is not expected to build-up in the tissues of organisms.

Non-target terrestrial organisms may be exposed to pyraziflumid residues through direct contact with spray or spray drift, contact with sprayed surfaces or from ingestion of contaminated food. Non-target aquatic organisms may be exposed to pyraziflumid through spray drift or runoff. When used according to the label directions, pyraziflumid poses acceptable risk to non-target organisms, including wild mammals, birds, beneficial insects, earthworms, terrestrial and aquatic plants, freshwater and marine invertebrates, algae, fish, and amphibians.

Value considerations

What is the value of Parade Fungicide?

The registration of Parade Fungicide will provide Canadian growers with a new active ingredient to manage economically important fungal diseases on apple while mitigating the risk of resistance development.

Parade Fungicide is applied to apple trees as a foliar spray to control powdery mildew and scab that, if left unmanaged, reduce yield and marketability of harvested fruit.

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 Pyraziflumid Technical and Parade Fungicide to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures

Human health

To reduce the potential of workers coming into direct contact with pyraziflumid on the skin or through inhalation, workers mixing, loading and applying Parade Fungicideand performing cleaning and repair activities must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. Chemical-resistant gloves are not required during application within a closed cab. The label also requires that workers do not enter or be allowed entry into treated apple orchards during the REI of 12 hours. Furthermore, standard label statements to protect against drift during application and to prevent the use of handheld airblast, misters and foggers are present on the label.

Environment

• Require a label statement indicating the potential for movement to groundwater.
• Require a general statement for reducing runoff from treated areas to aquatic habitats.
• Require a precautionary label statement indicating toxicity to non-target terrestrial plants and buffer zones of 1 to 2 metres as a precautionary measure to mitigate the potential risk.
• Require a precautionary label statement indicating toxicity to aquatic organisms.

Next steps

Before making a final registration decision on pyraziflumid and Parade Fungicide, Health Canada’s PMRA will consider any comments received from the public in response PRD2022-04. Health Canada will accept written comments on PRD2022-04 up to 45 days from the date of publication of PRD2022-04. 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 pyraziflumid and Parade Fungicide (based on the Science Evaluation of PRD2022-04). In addition, the test data referenced in this consultation document will be available for public inspection, upon application, in the PMRA’s Reading Room.