Proposed Registration Decision PRD2025-06, Cyclobutrifluram, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2

Pest Management Regulatory Agency
12 September 2025
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2025-6E-PDF (PDF version)

Summary

Table of contents

• Proposed registration decision for cyclobutrifluram
• What does Health Canada consider when making a registration decision?
• What is cyclobutrifluram?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
  • Key risk-reduction measures - Human health
  • Key risk-reduction measures - Environment
• Next steps
• Other information

Proposed registration decision for cyclobutrifluram

Health Canada's Pest Management Regulatory Agency (PMRA), pursuant to subsection 28(1) of the Pest Control Products Act, is proposing registration for the sale and use of Cyclobutrifluram Technical, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2, containing the technical grade active ingredient cyclobutrifluram, a nematicide and fungicide for use on romaine lettuce and as a soybean seed treatment.

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 in the full version of Proposed Registration Decision PRD2025-06, Cyclobutrifluram, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2 provides detailed technical information on the human health, environmental and value assessments of cyclobutrifluram and A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2.

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 individuals 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 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). They also consider the unique characteristics of 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 Health Canada regulates pesticides, the assessment process and risk-reduction programs, please visit the Pesticides and pest management portion of the Canada.ca website.

Before making a final registration decision on cyclobutrifluram, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2, Health Canada's PMRA will consider any written comments received from the public directly related to the proposed decision in this consultation document.^{Footnote 3} Health Canada will then publish a Registration Decision^{Footnote 4} on cyclobutrifluram, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2, 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 PRD2025-06.

What is cyclobutrifluram?

Cyclobutrifluram is a new conventional active ingredient for nematode and fungal disease management in Canada. As a nematicide, it works on contact and by systemic feeding activity on certain nematodes to disrupt ATP (adenosine triphosphate) production in nematode mitochondria. Cyclobutrifluram is also a systemic and selective fungicide that inhibits spore germination and mycelial growth of certain fungal pathogens.

Health considerations

Can approved uses of cyclobutrifluram affect human health?

A22011 Crop, A23156 Crop, VICTRATO, and VICTRATO 2, containing cyclobutrifluram, are unlikely to affect your health when used according to proposed label directions.

Potential exposure to cyclobutrifluram may occur through the diet (food and drinking water) or when handling and applying the end-use products, 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 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.

In laboratory animals, the technical grade active ingredient cyclobutrifluram was of low acute toxicity via the oral, dermal, and inhalation routes of exposure. It was not irritating to the eyes or skin and did not cause an allergic skin reaction.

The acute toxicity of end-use product A22011 Crop, containing cyclobutrifluram, was low via the oral, dermal and inhalation routes of exposure. It was minimally irritating to the eyes, and non-irritating to the skin. It did not cause an allergic skin reaction.

The acute toxicity of end-use product A23156 Crop, containing cyclobutrifluram, was low via the oral and inhalation routes of exposure and it was considered to be of low acute toxicity via the dermal route. A23156 Crop was slightly irritating to the skin. It was moderately irritating to the eyes and caused an allergic skin reaction; consequently, the signal word "WARNING" and hazard statements "EYE IRRITANT" and "POTENTIAL SKIN SENSITIZER" are required on the label.

The acute toxicity of end-use products VICTRATO and VICTRATO 2, containing cyclobutrifluram, was low via the oral, dermal and inhalation routes of exposure. VICTRATO and VICTRATO 2 were minimally irritating to the eyes and they did not cause an allergic skin reaction. VICTRATO and VICTRATO 2 were mildly irritating to the skin; consequently, the signal word and hazard statement "CAUTION – SKIN IRRITANT" are 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 cyclobutrifluram to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other potential human health hazards. The most sensitive endpoints for risk assessment were effects on body weight, sexual development and fertility, the lung and the thyroid. There was no evidence to suggest that cyclobutrifluram damaged genetic material. Cyclobutrifluram did, however, cause liver tumours in mice and thyroid tumours in rats. 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.

Occupational risks from handling A22011 Crop and A23156 Crop

Occupational risks are not of health concern when A22011 Crop and A23156 Crop are used according to the proposed label directions, which include protective measures.

Workers mixing, loading or applying A22011 Crop and A23156 Crop, and workers entering recently treated fields can be exposed to cyclobutrifluram residues through direct skin contact or through inhalation. Therefore, the labels specify that anyone mixing, loading and applying A22011 Crop and A23156 Crop and performing cleaning and repair activities must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. In addition, when mixing and loading A23156 Crop and performing cleaning and repair activities, workers must wear protective eyewear (goggles or face shield). The labels also require that workers do not enter or be allowed into treated fields 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 A22011 Crop and A23156 Crop are not of health concern when the end-use products are used according to the proposed label directions.

Occupational risks from handling VICTRATO and VICTRATO 2

Occupational risks are not of health concern when VICTRATO and VICTRATO 2 are used according to the proposed label directions, which include protective measures.

Workers treating soybean seed with VICTRATO and VICTRATO 2 in commercial facilities, by commercial mobile systems or on-farm, and workers planting treated soybean seed can come into direct contact with cyclobutrifluram residues on the skin and through inhalation.

The VICTRATO and VICTRATO 2 labels specify that workers mixing, loading, treating, and calibrating during commercial soybean seed treatment of soybean with open or closed transfer, must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. For good hygiene practice, it is also recommended to wear a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested. For bagging/sewing/stacking, any other activities involving handling treated seeds, and cleaning and repairing, workers must wear a long-sleeved shirt, long pants, chemical-resistant gloves, shoes and socks, and a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested.

When handling and planting commercially treated seed, workers must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks, and shoes and a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested, and must use a closed-cab tractor when planting. Gloves and respirator are not required within a closed cab.

On-farm workers involved in mixing, loading, transferring (either through an open or closed transfer system), treating, and calibrating, must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. In addition, when cleaning, repairing, handling and planting treated bulk or bagged seed, workers must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes and a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested, and must use a closed-cab tractor when planting. Gloves and respirator are not required within a closed cab.

Taking into consideration these label statements and the duration of exposure for handlers and workers, health risks to these individuals are not a concern.

Health risks in residential and other non-occupational environments

A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2 are not domestic class products and are not permitted for use in residential settings or other non-occupational environments.

Health risks to bystanders

Bystander risks are not of health concern when A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2are 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 labels. Therefore, health risks to bystanders are not of concern when the end-use products are used according to the proposed label directions.

Residues in food and drinking water

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

The basic acute aggregate dietary intake estimates (food plus drinking water) revealed that the general population, females aged 13–49 and infants less than one-year-old are expected to be exposed to less than 4% of the acute reference dose (ARfD). When the common metabolite trifluoroacetic acid (TFA) is included for rotational crops and drinking water, the highest exposure estimate is less than 4% of the ARfD (infants less than one-year old). Based on these estimates, the acute dietary risk from cyclobutrifluram is not of health concern.

The basic chronic aggregate dietary intake estimates (food plus drinking water) revealed that the general population and infants less than one-year old are expected to be exposed to less than 15% of the acceptable daily intake (ADI). When TFA is included for rotational crops and drinking water, the highest exposure estimate is less than 15% of the ADI (infants less than one-year old). Based on these estimates, the chronic dietary risk from cyclobutrifluram is not of health concern.

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 chronic dietary risk assessment are considered protective of the findings, 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. Given that dietary risks from the consumption of foods are shown to be acceptable when cyclobutrifluram is used according to the supported label directions, MRLs are being proposed as a result of this assessment (refer to PMRL2025-19, Cyclobutrifluram).

MRLs for cyclobutrifluram determined from the acceptable residue trials conducted throughout the United States and Brazil, including growing regions representative of Canada, on Romaine lettuce and soybeans, can be found in the Science evaluation section of PRD2025-06.

Environmental considerations

What happens when cyclobutrifluram is introduced into the environment?

When used according to label directions, the environmental risks associated with cyclobutrifluram and its associated end-use products are acceptable.

Cyclobutrifluram enters the environment when its end-use products A22011 Crop, A23156 Crop, VICTRATO, and VICTRATO 2 are used to control diseases in labelled crops or on treated seeds. Cyclobutrifluram breaks down in soil or water in the presence of light to form several major transformation products (SYN510275, CGA177291, EXC8199, SYN551241, SYN551231 and TFA) and one minor transformation product (SYN549104). Cyclobutrifluram is otherwise slow to break down in the environment in the absence of light.

Cyclobutrifluram and its transformation products may move through soil and reach groundwater. They may also move off the treatment area in runoff to reach surface water. Cyclobutrifluram is not expected to dissipate into air in significant quantities or to accumulate in the tissue of animals.

After a scientific review of the available information, the PMRA has concluded that the environmental risks from the proposed uses of cyclobutrifluram are acceptable when used according to label directions.

Value considerations

What is the value of A22011 Crop, A23156 Crop, VICTRATO, and VICTRATO 2?

Cyclobutrifluram is the active ingredient in A22011 Crop, A23156 Crop, VICTRATO, and VICTRATO 2. The registration of these products will provide Canadian growers with a new mode of action to manage important nematode infection and fungal diseases on the crops specified on these product labels.

A22011 Crop, A23156 Crop, VICTRATO, and VICTRATO 2 contain cyclobutrifluram as their sole active ingredient. A22011 Crop and A23156 Crop, applied as soil drench or banded spray applications, are effective against root-knot nematode in romaine lettuce. VICTRATO and VICTRATO 2, applied as seed treatments, are effective against soybean cyst nematode and early season Fusarium infection, the cause of sudden death syndrome in soybean.

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 Cyclobutrifluram Technical, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2 to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures - Human health

A22011 Crop and A23156 Crop

To reduce the potential exposure of workers to cyclobutrifluram through direct skin contact or inhalation of sprays, workers mixing, loading and applying A22011 Crop and A23156 Crop and performing cleaning and repair activities must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. Additionally, workers must wear protective eyewear (goggles or face shield) when mixing, loading, cleaning or performing repair activities involving A23156 Crop. The labels also require that workers do not enter or be allowed entry into treated areas during the REI of 12 hours. Risks to workers are not of health concern when A22011 Crop and A23156 Crop are used according to the proposed label directions and restricted-entry intervals (REIs) are observed. Furthermore, a standard label statement to protect against drift during application is present on the labels.

VICTRATO and VICTRATO 2

To reduce the potential exposure of workers to cyclobutrifluram through direct skin contact or inhalation of sprays, the VICTRATO and VICTRATO 2 labels specify that workers mixing, loading, treating, calibrating in commercial soybean seed treating facilities with open or closed transfer system, must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. For good hygiene practice, it is also recommended to wear a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested. For bagging/sewing/stacking, any other activities involving handling treated seeds, and cleaning and repairing, workers must wear a long-sleeved shirt, long pants, chemical-resistant gloves, shoes and socks, and a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested.

When handling and planting commercially treated seed, workers must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks, and shoes and a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested and must use closed-cab tractor when planting. Gloves and respirator are not required within a closed cab.

On-farm workers involved in mixing, loading, transferring (either through an open or closed transfer system), treating, calibrating, wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. In addition, when cleaning, repairing, handling and planting treated bulk or bagged seed, workers must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes and a NIOSH-approved N95 (minimum) filtering facepiece respirator (dust mask) that is properly fit tested and must use closed-cab tractor when planting. Gloves and respirator are not required within a closed cab. Furthermore, a standard label statement to protect against drift during application is present on the labels.

Key risk-reduction measures - Environment

• Precautionary label statements to inform users of the toxicity of cyclobutrifluram to aquatic organisms.
• Best management practice label statements to instruct users to avoid using the end-use products in areas more conducive to leaching to groundwater (in other words, where the soils are permeable and particularly where the water table is shallow).
• Best management practice label statements to reduce runoff entering sensitive aquatic habitats.
• Best management practice label statements to inform users to clean up spilled seed when cyclobutrifluram is used as a seed treatment.

Next steps

Before making a final registration decision on cyclobutrifluram, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2, Health Canada's PMRA will consider any written comments received from the public that are directly related to this proposed decision, such as comments directed to the science evaluation in response to this consultation document up to 30 days from the date of publication (12 September 2025) of this document. If more time is required to provide comments, a request for an extension of up to 15 days can be made before the end of the original 30-day consultation period. 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 PMRA Publications, through the Public Engagement Portal (Public Engagement Forms – Consultation Comment. 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 Health Canada makes its registration decision, it will publish a Registration Decision on cyclobutrifluram, A22011 Crop, A23156 Crop, VICTRATO and VICTRATO 2 (based on the Science Evaluation of PRD2025-06). 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 or if you have questions, please contact the Pest Management Information Service.