Proposed Registration Decision PRD2024-07, Nealta Miticide, containing Cyflumetofen (2024)

• Pest Management Regulatory Agency
• 11 June 2024
• ISSN: 1925-0886 (PDF version)
• Catalogue number: H113-9/2024-7E-PDF (PDF version)

Summary

Table of contents

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

Proposed registration decision for Nealta Miticide

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 Nealta Miticide, containing the technical grade active ingredient cyflumetofen to control various mites on greenhouse crops, specifically strawberries, tomatoes, peppers and cucumbers. This evaluation was completed under the User Requested Minor Use Label Expansion program, which is a cooperative program between Agriculture and Agri-Food Canada and Health Canada's Pest Management Regulatory Agency and includes participation by sponsor groups, manufacturers, and both provincial and federal governments.

Cyflumetofen is currently registered to control several mite species on field-, bed- and container grown conifers including Christmas trees; hops; pome fruits; stone fruits; grapes; cucurbit vegetables; field grown tomato and strawberry; and outdoor ornamentals. For details, see Proposed Registration Decision PRD2014-10, Cyflumetofen, and Registration Decision RD2014-24, Cyflumetofen.

An evaluation of available scientific information found that, under the approved conditions of use, the health and environmental risks and the value of Nealta Miticide, containing cyflumetofen, are acceptable.

This summary describes the key points of the evaluation, while the Science evaluation of the full version of the Proposed Registration Decision PRD2024-07, Nealta Miticide, containing Cyflumetofen provides detailed technical information on the human health, environmental and value assessments of Nealta Miticide, containing cyflumetofen on greenhouse food crops.

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 Health Canada 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 on how the Health Canada regulates pesticides, the assessment process and risk-reduction programs, please visit the Pesticides and pest management section of Canada.ca.

Before making a final registration decision on Nealta Miticide containing cyflumetofen, Health Canada's PMRA will consider any written comments received from the public in response to this consultation document.^{Footnote 3} Health Canada will then publish a Registration Decision^{Footnote 4} on Nealta Miticide, containing cyflumetofen, 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 PRD2024-07.

What is cyflumetofen?

Cyflumetofen is a beta-ketonitrile derivative. It interferes with energy production within cells and acts as an acaricide on contact with spider mites. Foliar application of cyflumetofen formulated as Nealta Miticide provides control of spider mites on greenhouse strawberry, tomato, pepper and cucumber.

Health considerations

Can approved uses of cyflumetofen affect human health?

Nealta Miticide, containing cyflumetofen, is unlikely to affect your health when used according to label directions.

Potential exposure to cyflumetofen may occur through the diet (food and drinking water), when handling and applying the end-use product, or when entering an area that has been treated with the product. 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 selected 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 dose levels 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.

As described in PRD2014-10 and RD2014-24, the technical grade active ingredient cyflumetofen was of low acute toxicity by the oral, dermal, and inhalation routes of exposure in laboratory animals. It was minimally irritating to the eyes and non-irritating to the skin. Cyflumetofen caused an allergic skin reaction; consequently, the hazard statement "POTENTIAL SKIN SENSITIZER" is required on the label.

The acute toxicity of the end-use product Nealta Miticide, containing cyflumetofen, was low via the oral, dermal and inhalation routes of exposure. Nealta Miticide was non-irritating to the eyes, minimally irritating to the skin and did not cause an allergic skin reaction.

Prior to the initial registration of cyflumetofen, 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 cyflumetofen to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. As described in PRD2014-10 and RD2014-24, the most sensitive endpoints for risk assessment were effects on the adrenal glands. There was no evidence that cyflumetofen damaged genetic material; however, it did cause testicular tumours and thyroid tumours in male rats. 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. There was no evidence of increased sensitivity of the young compared to adult animals, although a serious endpoint (a birth defect) was noted in rabbit fetuses at a dose level that was also toxic to the mothers. The risk assessment protects against the effects noted above, including the potential to cause cancer, 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 indicated that females 13–49 years old are exposed to less than 2% of the acute reference dose, and therefore are not of health concern. Studies in laboratory animals showed that acute health effects are unlikely to occur in any other population subgroup. Consequently, a single dose of cyflumetofen is not likely to cause acute health effects in other population subgroups (including infants and children).

Aggregate chronic dietary (food plus drinking water) intake estimates indicated that the general population and all population subgroups are exposed to less than 7% of the acceptable daily intake, and therefore are not of health concern.

Overall, the reference values selected for the chronic dietary risk assessment are considered protective of the findings in animal toxicity tests, including potential cancer effects.

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 Canada and the United States on greenhouse strawberries, greenhouse tomatoes, greenhouse bell and non-bell peppers and greenhouse cucumbers are acceptable. The MRLs for cyflumetofen can be found in the Science Evaluation of this consultation document.

Occupational risks from handling Nealta Miticide

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

Workers mixing, loading or applying Nealta Miticide, and workers entering recently treated greenhouses can come in direct contact with cyflumetofen residues on the skin and through inhalation. Therefore, the label specifies that anyone mixing, loading and applying Nealta Miticide must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. In addition, there is a restriction on applying Nealta Miticide using handheld airblast/mistblower equipment or foggers in the greenhouse. 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 from exposure to Nealta Miticide are not of health concern when the end-use product is used according to the proposed label directions.

Health risks to bystanders

Bystander risks are not of health concern when Nealta Miticide is 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 cyflumetofen is introduced into the environment?

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

Cyflumetofen enters the environment when applied as a foliar spray to control mites on various greenhouse fruits, including strawberries, tomatoes, peppers, and cucumbers, and residues from this spray are released from the greenhouse in effluent or runoff water. When cyflumetofen is released into the environment, it can enter soil and surface water.

As described in PRD2014-10 and RD2014-24, cyflumetofen is not persistent in the terrestrial environment where biotransformation and hydrolysis in moist soils are the main routes of transformation. Cyflumetofen is not expected to volatilize, and leaching to groundwater is not a concern.

Cyflumetofen is not persistent in the aquatic environment. Once in water, it rapidly undergoes transformation by photolysis and hydrolysis at environmentally relevant pHs, particularly alkaline pH. Cyflumetofen is also rapidly broken down by microbial activity in water and sediments, and it is not expected to bioaccumulate in fish tissue.

Many transformation products of cyflumetofen were identified in the abiotic transformation, and soil and aquatic biotransformation laboratory studies. Generally, major transformation products with a large chemical structure similar to cyflumetofen, such as AB-1 and AB-1 dimers, tend to be immobile like the parent; while those with a small chemical structure (having a single benzene ring only), such as A-2, B-1, and B-3, tend to be mobile in soil.

Cyflumetofen does not present a risk of concern to terrestrial organisms, such as earthworms, beneficial insects (bees and other beneficial arthropods), birds, and small mammals. However, a risk to non-target terrestrial plants was identified. Cyflumetofen is not expected to pose a risk to freshwater or marine fish, invertebrates, or algae, but a risk was identified to amphibians. Mitigation measures, including a label statement preventing effluent or runoff from greenhouses entering lakes, streams, ponds, or other waters, are required to reduce exposure to these organisms. When cyflumetofen is used according to the label, the environmental risks are considered acceptable.

Value considerations

What is the value of Nealta Miticide?

Nealta Miticide contains the active ingredient cyflumetofen and controls spider mites on greenhouse cucumber, pepper, tomato and strawberry.

The use of Nealta Miticide to control spider mites on greenhouse food crops is new. The product is applied to the foliage of these crops. Nealta Miticide represents a new mode of action against spider mites on greenhouse cucumber, pepper, tomato and strawberry. Therefore, it may aid in resistance management of these pests on these 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 Nealta Miticide to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures - Human health

To reduce the potential exposure of workers to cyflumetofen through direct contact on the skin or through inhalation, workers mixing, loading and applying Nealta Miticide and performing cleaning and repair activities must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. The label also requires that workers do not enter or be allowed entry into treated areas during the REI of 12 hours. Furthermore, a standard label statement to protect against drift during application and to prevent the use of handheld or automated airblast, mistblowers and foggers in the greenhouse are present on the label.

Key risk-reduction measures - Environment

A label statement preventing effluent or runoff from greenhouses entering lakes, streams, ponds, or other waters.

Next steps

Before making a final registration decision on Nealta Miticide, containing cyflumetofen, Health Canada's PMRA will consider any written comments received from the public in response to this consultation document up to 45 days from the date of publication (11 June 2024) of PRD2024-07. 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 Nealta Miticide, containing cyflumetofen, (based on the Science evaluation of PRD2024-07). In addition, the test data referenced in this consultation document will be available for public inspection, upon application, in the PMRA's Reading Room. For more information, please contact the PMRA's Pest Management Information Service.