Proposed Registration Decision PRD2023-04, Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex

Pest Management Regulatory Agency
2 May 2023
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2023-4E-PDF (PDF version)

Summary

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 PRD2023-04, Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex please contact our publications office.

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

Table of contents

• Proposed Registration Decision for Plutella xylostella granulovirus (PlxyGV) isolate GV-0020
• What does Health Canada consider when making a registration decision?
• What is Plutella xylostella granulovirus (PlxyGV) isolate GV-0020?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
• Next steps
• Other information

Proposed Registration Decision for Plutella xylostella granulovirus (PlxyGV) isolate GV-0020

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 PlxyGV Technical and Plutex, containing the technical grade active ingredient Plutella xylostella granulovirus (PlxyGV) isolate GV-0020, to control diamondback moth larvae on canola and field-grown Brassica Head and Stem Vegetables (Crop Group 5-13).

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 PRD2023-04, Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex provides detailed technical information on the human health, environmental and value assessments of Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex.

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

Before making a final registration decision on Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex, 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 Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex, 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 PRD2023-04.

What is Plutella xylostella granulovirus (PlxyGV) isolate GV-0020?

Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 is an insect-specific virus that infects and kills larvae of the diamondback moth, an important insect pest of crop plants in the plant family Brassicaceae.

Health considerations

Can approved uses of Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 affect human health?

Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 is unlikely to affect your health when Plutex is used according to the label directions.

Potential exposure to Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 may occur through the diet (food and water) or when handling and applying Plutex. When assessing health risks, several key factors are considered:

• the microorganism's biological properties (for example, infection cycle);
• reports of any adverse incidents;
• its potential to cause disease or toxicity as determined in toxicological studies; and
• the level to which people may be exposed relative to exposures already encountered in nature to other isolates of this microorganism.

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 that are determined as having no health risks of concern are considered acceptable for registration.

Studies in laboratory animals describe potential health effects from large doses of exposure to a microorganism and identify any pathogenicity, infectivity and toxicity concerns.
When other baculoviruses were tested on laboratory animals and in tissue cultures, there were no signs of significant toxicity or disease. Furthermore, there have been no reported adverse effects despite the natural occurrence and prevalence of baculoviruses in the environment, and the limited host range associated with baculoviruses has been well documented. In the absence of eye irritation testing, the technical grade active ingredient and end-use product are assumed to be eye irritants.

The technical grade active ingredient, PlxyGV Technical, and the end-use product, Plutex, are considered potential sensitizers.

Residues in water and food

Dietary risks from food and water are acceptable.

Residues of Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 on treated agricultural crops are possible at the time of harvest. Although baculoviruses, including Plutella xylostella granulovirus (PlxyGV) isolate GV-0020, are abundant in nature, no adverse effects from dietary exposure have been attributed to natural populations of Plutella xylostella granulovirus. Furthermore, no signs of infectivity or toxicity were observed when baculoviruses were tested on laboratory animals and in tissue culture studies. In addition, the likelihood of residues of Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 contaminating drinking water supplies is expected to be low as the label has the necessary mitigation measures to limit contamination of drinking water from the proposed uses of Plutex. Consequently, dietary risks are acceptable for all segments of the population, including infants, children, adults and seniors.

Occupational risks from handling Plutex

Occupational risks are acceptable when Plutex is used according to label directions, which include protective measures.

Workers handling Plutex can be exposed to Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 through direct skin or eye contact or through inhalation. To protect workers from exposure to Plutex, the label states that workers must wear personal protective equipment, including a long-sleeved shirt, long pants, protective eyewear (goggles), waterproof gloves, socks and shoes, and a NIOSH-approved particulate filtering facepiece respirator with any N, R or P filter. The product label includes measures to restrict access to the treated area for four hours or until sprays have dried.

The occupational risks are acceptable when the precautionary statements on the label are observed.

Risks in residential and other non-occupational environments

Estimated risk for non-occupational exposure acceptable.

Plutex is being proposed for use as a commercial insecticide on various outdoor food crops. There are no residential uses. The product label includes mitigation measures to prevent bystander exposure such as reducing spray drift. Residential and non-occupational exposure to Plutex is therefore expected to be low when the label directions are observed. Consequently, the risk to residents and the general public is acceptable.

Environmental considerations

What happens when Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 is introduced into the environment?

Environmental risks are acceptable.

Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 is a naturally occurring baculovirus that specifically infects lepidopteran insects. Baculoviruses are common and persistent in aquatic and terrestrial ecosystems. Plutex is a new end-use product that is proposed for use as an insecticide to control diamondback moth on field-grown crops (Brassica Head and Stem Vegetables and canola), and is not intended for aquatic applications. The field use of Plutex is not expected to result in sustained increases of Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 in terrestrial and aquatic environments beyond natural background levels.

Based on a critical review of animal studies, scientific rationales and information from public sources, no significant effects to birds, wild mammals, fish, terrestrial and aquatic non-target arthropods, and plants are expected when Plutex is applied according to directions on the label.

Value considerations

What is the value of Plutex?

Plutex, containing Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 at a minimum concentration of 2.5 × 1013 occlusion bodies (OBs)/L, is a microbial bio-insecticide that specifically infects and kills larvae of the diamondback moth.

The development of resistance to insecticides is a considerable problem in the diamondback moth, which makes this pest a challenge for growers of canola, broccoli, Brussels sprouts, cabbage and cauliflower. Plutex will provide these growers with an additional microbial bio-pesticide active ingredient for use against the diamondback moth that may be used to manage diamondback moths that are resistant to other registered active ingredients. Because Plutex contains a narrow spectrum active ingredient, it will not infect natural enemies of the diamondback moth and, consequently, may allow a degree of biological control of this pest, a key goal of integrated pest management.

Measures to minimize risk

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

The key risk-reduction measures being proposed on the labels of PlxyGV Technical and Plutex to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures - Human health

The signal words "POTENTIAL SENSITIZER" and "CAUTION EYE IRRITANT" will appear on the primary display panel of the labels.

The end-use product and technical grade active ingredient are considered potential sensitizers. In turn, workers handling or applying Plutex must wear a long-sleeved shirt, long pants, protective eyewear (goggles), waterproof gloves, socks and shoes and a NIOSH-approved particulate filtering facepiece respirator with any N, R or P filter. Furthermore, all unprotected workers are restricted from entering treated areas during application and for four hours following application or until sprays have dried.

A standard drift statement is required on the Plutex label to minimize the potential for drift to areas of human habitation or areas of human activity such as houses, cottages, schools and recreational areas as well as statements to limit contamination of water supplies through cleaning or waste disposal.

Key risk-reduction measures - Environment

The end-use product label will include environmental precaution statements that prevent the runoff and contamination of aquatic systems from the use of Plutex.

Next steps

Before making a final registration decision on Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex, Health Canada's PMRA will consider any comments received from the public in response to PRD2023-04. Health Canada will accept written comments on this proposal up to 45 days from the date of publication of PRD2023-04. 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 Plutella xylostella granulovirus (PlxyGV) isolate GV-0020 and Plutex (based on the Science Evaluation of PRD2023-04). In addition, the test data referenced in this consultation document will be available for public inspection, upon application, in the PMRA's Reading Room. For more information, please contact the PMRA's Pest Management Information Service.