Proposed Registration Decision PRD2021-03, Fluazaindolizine and Salibro Nematicide

Pest Management Regulatory Agency
18 June 2021
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2021-3E-PDF (PDF version)

Summary

Table of contents

• Proposed registration decision for fluazaindolizine and Salibro Nematicide
• What does Health Canada consider when making a registration decision?
• What is fluazaindolizine?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
• Key risk-reduction measures
• Additional information being requested
• Next steps
• Other information

Proposed registration decision for fluazaindolizine and Salibro Nematicide

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 Reklemel Technical and Salibro Nematicide, containing the technical grade active ingredient fluazaindolizine, to control root-knot nematodes in tuberous and corm vegetables (Crop Subgroup 1C), carrot, cucurbit vegetables (Crop Group 9) and fruiting vegetables (Crop Group 8-09).

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 PRD2021-03, Fluazaindolizine and Salibro Nematicide provides detailed technical information on the human health, environmental and value assessments of fluazaindolizine and Salibro Nematicide.

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 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 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 fluazaindolizine and Salibro Nematicide, Health Canada's PMRA will consider any comments received from the public in response to PRD2021-03. Health Canada will then publish a Registration Decision on fluazaindolizine and Salibro Nematicide, 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 PRD2021-03.

What is fluazaindolizine?

Fluazaindolizine is a nematicide that protects vegetable crops from root-knot nematodes, which induce galls on roots, stunt plants and cause yield losses. Fluazaindolizine results in paralysis of root-knot nematodes followed by mortality.

Health considerations 

Can approved uses of fluazaindolizine affect human health?

Salibro Nematicide, containing fluazaindolizine, is unlikely to affect your health when used according to label directions.
Potential exposure to fluazaindolizine may occur through the diet (food and drinking water), 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 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 fluazaindolizine was of low acute toxicity via the dermal and inhalation routes of exposure. It was minimally irritating the skin, and did not cause an allergic skin reaction.

Fluazaindolizine was of moderate acute toxicity via the oral route of exposure and mildly irritating to the eyes; consequently, the signal word “WARNING” and hazard statements “POISON” and “EYE IRRITANT” are required on the label.

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

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 fluazaindolizine to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. The most sensitive endpoints for risk assessment were effects on the kidney, adrenal glands and liver. 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 at which these effects occurred in animal tests.

Residues in food and drinking water

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

Aggregate dietary intake estimates (food plus drinking water) revealed that the general population and all infants, the subpopulation which would ingest the most fluazaindolizine relative to body weight, are expected to be exposed to less than 30%of the acute reference dose. Based on these estimates, the acute dietary risk from fluazaindolizine is not of health concern for all population subgroups.

Aggregate dietary intake estimates (food plus drinking water) revealed that the general population and all infants, the subpopulation which would ingest the most fluazaindolizine relative to body weight, are expected to be exposed to less than 74%of the acceptable daily intake. Based on these estimates, the chronic dietary risk from fluazaindolizine is not of health concern for all population subgroups.

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) using fluazaindolizine on the primary crops of carrots, potatoes (Crop Subgroup 1C), fruiting vegetables (Crop Group 8-09), and cucurbit vegetables (Crop Group 9) and field accumulation trials (limited and extended) conducted in various North American and European regions on several crops/crop groups are acceptable. The MRLs for this active ingredient can be found in the Science evaluation of PRD2021-03.

Risks in residential and other non-occupational environments

A residential risk assessment was not required since the product is not a domestic class product and is not permitted for use in residential areas.

Occupational risks from handling Salibro Nematicide

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

Farmers and custom applicators who mix, load or apply Salibro Nematicide can come in direct contact with fluazaindolizine on the skin and through inhalation. In addition, there is the potential for workers to be exposed during postapplication activities when they come in direct contact with Salibro Nematicide residues in treated soil and when moving irrigation lines during or after chemigation. Therefore, the label specifies that anyone mixing, loading and applying Salibro Nematicide must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. Gloves are not required during application while in a closed cab. In addition, for chemigation application, workers are required to wear personal protective equipment as defined in the personal protective equipment (PPE) section of the label for mixers/loaders/applicators when making adjustments or repairs on the chemigation system when this product is in the irrigation water. The label also requires that workers not enter treated fields for twelve (12) hours after application. Taking into consideration these label statements, the number of applications and the expectation of the exposure period for handlers and workers, risks to these individuals are not a concern.

For bystanders, exposure is expected to be negligible. Therefore, health risks to bystanders are not of concern.

Environmental considerations

What happens when fluazaindolizine is introduced into the environment?

When used according to label directions, environmental risks associated with fluazaindolizine and its associated end-use product are acceptable.

Fluazaindolizine enters the environment when Salibro Nematicide is used to control nematodes in labelled crops. Fluazaindolizine is broken down by microorganisms in the environment. On land, fluazaindolizine and its transformation products may move through soil and reach groundwater. Fluazaindolizine is not expected to be found in air or to travel long distances in the atmosphere from where it is applied. It is also not expected to accumulate in the tissues of plants or animals.

When used according to label directions, the risks from fluazaindolizine to terrestrial and aquatic organisms are acceptable. A precautionary label statement to inform users of the potential for leaching will be required.

Value considerations

What is the value of Salibro Nematicide?

Fluazaindolizine is the active ingredient in Salibro Nematicide. The registration of Salibro Nematicide will provide Canadian vegetable growers with a new product to manage root-knot nematodes, which can cause serious crop and economic losses.

Salibro Nematicide is applied to soil or by chemigation to protect tuberous and corm vegetables (Crop Subgroup 1C), cucurbit vegetables (Crop Group 9), fruiting vegetables (Crop Group 8-09) and carrots from root damage caused by parasitic root-knot nematodes.

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 Reklemel Technical Nematicide, and Salibro Nematicide to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures

Human health

Because users may come into direct contact with Salibro Nematicide on the skin and through inhalation, anyone mixing, loading and applying Salibro Nematicide must wear a long-sleeved shirt, long pants, chemical-resistant gloves, socks and shoes. Chemical-resistant gloves are not required during application while in a closed cab. For chemigation application, workers are required to wear personal protective equipment as defined in the PPE section of the label for mixers/loaders/applicators when making adjustments or repairs on the chemigation system when this product is in the irrigation water.

In addition, standard label statements to protect against drift during application was added to the label. For postapplication re-entry activities, workers must not enter into treated areas during the restricted-entry interval (REI) of 12 hours.

Environment

A label statement to inform users of the potential for leaching, and to provide mitigation measures to reduce leaching.

Additional information being requested

Since this technical product is manufactured only at pilot scale before registration, five-batch data representing commercial-scale production will be required as postmarket information after registration.

Next steps

Before making a final registration decision on fluazaindolizine and Salibro Nematicide, Health Canada's PMRA will consider any comments received from the public in response to PRD2021-03. Health Canada will accept written comments on this proposal up to 45 days from the date of publication of PRD2021-03. 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 (contact information on the cover page of this document). 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 fluazaindolizine and Salibro Nematicide (based on the Science evaluation of PRD2021-03). In addition, the test data referenced in PRD2021-03 will be available for public inspection, upon application, in the PMRA's Reading Room (located in Ottawa).