Proposed Registration Decision PRD2025-08, Heptyl Butyrate, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap

Pest Management Regulatory Agency
12 September 2025
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2025-8E-PDF (PDF version)

Table of contents

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

Proposed registration decision for heptyl butyrate

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 Rescue Yellowjacket Technical, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap, containing the technical grade active ingredient heptyl butyrate, to control yellowjackets in urban and rural residential and recreational areas.

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 PRD2025-08, Heptyl Butyrate, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap provides detailed technical information on the human health, environmental and value assessments of heptyl butyrate and Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap.

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 heptyl butyrate, Rescue Yellowjacket Technical, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap, 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 heptyl butyrate, Rescue Yellowjacket Technical, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap, 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 PRD2025-08.

What is heptyl butyrate?

Heptyl butyrate is a non-conventional, colourless liquid with a fruity/floral scent. It is found naturally in apples and plums and is classified as a food-grade edible.^{Footnote 5} Heptyl butyrate is used as a yellowjacket attractant (bait), luring the insects towards the traps by scent.

Health considerations

Can approved uses of heptyl butyrate affect human health?

Heptyl butyrate is unlikely to affect human health when used according to label directions.

Potential exposure to heptyl butyrate may occur when handling products, including during set-up and disposal, or when standing close enough to inhale the scent from the traps once they are hanging outdoors.

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. 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 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.

Publicly available toxicology information on heptyl butyrate and its analogs was used to address the toxicity of heptyl butyrate. Heptyl butyrate is considered to be of low acute toxicity by the oral route, slightly acutely toxic by the inhalation route, mildly irritating to skin, and is minimally irritating to eyes. Heptyl butyrate is not expected to be a dermal sensitizer and is not considered to be mutagenic or genotoxic.

Publicly available toxicology information indicates that when animals were given repeated high doses of a compound similar to heptyl butyrate by the oral route of exposure, females exhibited increased kidney weight.

Publicly available toxicological information from compounds similar to heptyl butyrate indicates that pregnant animals exposed by the oral route of exposure had reduced body weight at doses which caused some fetal variations. Local respiratory effects occurred via the inhalation route. The young were not more sensitive than the adult animal.

End-use products

The end-use products, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill and Yellowjacket Trap, contain heptyl butyrate as a wasp attractant (bait). Published scientific literature and publicly available information for the active ingredient was used to inform the toxicology profile of the end-use products. Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill and Yellowjacket Trap are of low acute oral toxicity, slightly acutely toxic by the inhalation route, mildly irritating to skin, and minimally irritating to eyes. The end-use products are not expected to be dermal sensitizers.

Residues in food and drinking water

Dietary risks from food and drinking water are acceptable.

The end-use products, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill and Yellowjacket Trap, are not proposed for food or feed uses. Dietary exposure, including drinking water, is not expected from the proposed use of heptyl butyrate as a wasp attractant (bait). Consequently, a dietary risk assessment is not required.

Risks in residential and other non-occupational environments

Estimated risk for residential and other non-occupational exposure is acceptable.

Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill and Yellowjacket Trap are domestic-class products proposed for outdoor use to trap yellowjacket wasps on residential properties. Disposable Yellowjacket Trap-W is a disposable trap that contains a water-soluble bait pouch and can be disposed of in the garbage. Yellowjacket Trap Cartridge Refill is a sealed cartridge containing a piece of felt infused with the attractant while the Yellowjacket Trap is a refill tube containing the attractant. The refills can be used to rebait the reusable version of the wasp trap.

The product labels will include measures to reduce user and residential bystander (including children and companion animals) exposure such as instructions to keep children away from the product and to use scissors when opening the attractant packet/tube of the Yellowjacket Trap. Furthermore, the trap is used outdoors only.

Overall, residential and non-occupational exposure to Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap is expected to be low when label directions are observed. Consequently, the health risk to residents and the general public is acceptable.

Occupational risk assessments are not required for Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill and Yellowjacket Trap.

Since Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap are domestic products, an occupational risk assessment is not required.

Environmental considerations

What happens when heptyl butyrate is introduced into the environment?

When used according to label directions, the risks associated with the use of heptyl butyrate in yellowjacket trap products are acceptable from the viewpoint of environmental protection.

Disposable Yellowjacket Trap-W contains heptyl butyrate in a water-soluble pouch (solubag) contained within a plastic bag trap. Water must be added to activate the trap. The reusable Yellowjacket Trap is a rigid plastic trap that can be baited using the Yellowjacket Trap Cartridge Refill or the Yellowjacket Trap. The traps are hung around human residential areas in which yellowjackets are a nuisance. Heptyl butyrate is used as an attractant and has a non-toxic mode of action; as it volatilizes, yellowjackets are attracted into the traps, which have a conical one-way entrance that prevents escape from the traps. Field studies show that non-target organisms, including bees and other beneficial arthropods, do not enter the traps. Because the active ingredient is contained within the traps, there is also limited potential for exposure of non-target organisms in adjacent aquatic and terrestrial habitats. The primary route of environmental exposure is via volatilization. Heptyl butyrate is not persistent in the atmosphere, and volatilized heptyl butyrate will quickly dissipate. Therefore, the environmental risks associated with the yellowjacket trap products are acceptable when they are used according to label directions.

Value considerations

What is the value of Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap?

The trap and associated refill products can be used to attract, trap, and subsequently reduce populations of nuisance yellowjackets.

The registration of Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap will provide Canadians with a non-conventional method of reducing nuisance yellowjackets in urban and rural residential and recreational areas compared to sprays or baits with conventional insecticides. Due to the non-conventional mode of action of this product, resistance is very unlikely to occur and therefore these products may aid in reducing insecticide resistance in yellowjacket populations.

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 Rescue Yellowjacket Technical, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures - Human health

The following signal words and hazard statements are required on the label for Rescue Yellowjacket Technical, and the end-use products, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap :

• "CAUTION – POISON" and "SKIN IRRITANT"

Additionally, standard hazard and precautionary statements are required on the technical and end-use product labels to inform users that products can be harmful if inhaled, to avoid contact with skin and "Keep out of the reach of children." The use of scissors to open the attractant packet/tube for Yellowjacket Trap will also be indicated on the label to minimize the risk of exposure.

Key risk-reduction measures - Environment

The environmental risks associated with the use of heptyl butyrate as an attractant in traps to control yellowjackets were determined to be acceptable without the need for additional risk mitigation measures.

Next steps

Before making a final registration decision on heptyl butyrate, Rescue Yellowjacket Technical, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap, 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 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 heptyl butyrate, Rescue Yellowjacket Technical, Disposable Yellowjacket Trap-W, Yellowjacket Trap Cartridge Refill, and Yellowjacket Trap (based on the Science evaluation section of PRD2025-08). 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