Proposed Registration Decision PRD2024-03, Copper (Metallic) and V2 Net

Pest Management Regulatory Agency
8 March 2024
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2024-3E-PDF (PDF version)

Summary

Table of contents

• Proposed registration decision for Copper (Metallic)
• What does Health Canada consider when making a registration decision?
• What is copper (metallic)?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
• Next steps
• Other information

Proposed registration decision for Copper (Metallic)

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 Copper Flake Technical and V2 Net, containing the technical grade active ingredient copper (metallic), for antifouling protection of fish farm nets against organisms such as hydroids, barnacles, and mussels and for fish containment and protection in fresh, brackish, and marine waters.

Copper (metallic) was first registered in 2004 and is registered as a broad-spectrum fungicide, algaecide, aquatic herbicide, molluscicide, and antimicrobial for use on indoor surfaces and materials. For details, see Proposed Re-evaluation Decision PRVD2009-04, Copper Pesticides, and Re-evaluation Decision RVD2010-05, Copper Pesticides.

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 PRD2024-03, Copper (Metallic) and V2 Net provides detailed technical information on the human health, environmental, and value assessments of copper (metallic) and V2 Net.

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 section of the Canada.ca website.

Before making a final registration decision on copper (metallic) and V2 Net, Health Canada's PMRA will consider any written comments received from the public in response to PRD2024-03^{Footnote 3}. Health Canada will then publish a Registration Decision^{Footnote 4} on copper (metallic) and V2 Net, 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 the full version of PRD2024-03.

What is copper (metallic)?

Copper is a naturally occurring, ubiquitous element in the environment. Copper is found in water and air and occurs naturally in various foods including organ meats, seafood, beans, nuts, and whole grains. In most foods, copper is bound to macromolecules rather than remaining as a free ion. For many animals, copper is essential for the homeostasis of life. The role of copper in maintaining normal health both in humans and animals has been recognized for many years.

Copper-containing pesticides are formulated using various forms of copper, which ultimately dissociates into the cupric ion, the active component. There are a number of pesticidal active ingredients containing copper registered in Canada. These include pesticides that are used in agriculture, such as cuprous oxide, copper sulfate pentahydrate, copper oxychloride, copper hydroxide and copper sulphate. There are also pesticides that have only antimicrobial uses, such as copper naphthenate, copper 8-quinolinolate, copper (metallic) and cupric oxide. In PRVD2009-04, copper (metallic) is referred to as "metallic copper" or as "metallic copper powder".

Copper (metallic) is a conventional active ingredient with antimicrobial properties. When a surface or material is embedded with copper, copper ionic species can be released, and when contacting an organism's cell membrane, it generates reactive oxygen species which causes cell death.

Throughout this document, the technical grade active ingredient is referred to as "copper (metallic)." The more general term "copper" is used when referring to the metal itself, as well as to alloys, or compounds that contain copper.

Health considerations

Can approved uses of copper (metallic) affect human health?

Copper (metallic) is unlikely to affect human health when used according to label directions.

Potential exposure to copper (metallic) may occur through the diet (food and water) or when handling the product. When assessing health risks, two key factors are considered: the levels where 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.

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.

In laboratory animals, copper (metallic) was of high acute toxicity via the oral route, low acute toxicity via the dermal route, and moderate acute toxicity via the inhalation route. Copper (metallic) was slightly irritating to the eyes, not irritating to the skin, and not a dermal sensitizer.

There was no evidence of copper being carcinogenic or resulting in any other systemic toxicity in animals having normal copper homoeostasis. Available studies in animals generally indicate that the main concern for reproductive and developmental effects is associated with copper deficiency rather than excess.

The end-use product, V2 Net, is considered to be of low acute toxicity by the oral, dermal, and inhalation routes, slightly irritating to the eyes, not irritating to the skin, and not a dermal sensitizer.
Copper is a naturally occurring metal that is present in many foods and in drinking water. Copper is also an essential element in maintaining normal health in humans, with adverse effects more likely to result from copper deficiency rather than excess.

Residues in drinking water and food

Dietary risks from food and drinking water are acceptable.

Copper leaching from V2 Net and taken up by fish grown in the aquaculture enclosures is not expected to exceed background concentrations in the fish or in any potential source of drinking water. Consequently, health risks from dietary exposure are acceptable for all segments of the population, including infants, children, adults, and seniors.

Risks in residential and other non-occupational environments

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

Individuals engaged in recreational aquatic activities near the deployed V2 Nets are not expected to be exposed to levels of the active ingredient exceeding natural background concentrations. Consequently, the health risk to residents and the general public is acceptable.

Occupational risks from handling V2 Net

Occupational risks are acceptable when V2 Net is used according to the label directions, which include protective measures.
Workers handling V2 Net can come into direct contact with copper (metallic) through contact with the skin during deployment, retrieval, maintenance, and cleaning of the nets.

To protect workers from exposure to the end-use product, the precautionary label statements indicate that contact with eyes must be avoided and that gloves must be worn when handling. Precautionary and hygiene statements on the label are considered adequate to protect individuals from occupational exposure.

The health risks to workers are acceptable when the precautionary statements on the label are observed.

Environmental considerations

What happens when copper (metallic) is introduced into the environment?

When copper (metallic) is used according to the label directions, the risks to the environment are acceptable.

When copper (metallic) is present as a component of the V2 Net netting material used in aquaculture nets, it will enter the aquatic environment when the netting material comes in contact with water. Once in the water, the copper (metallic) will be rapidly diluted within seconds. Copper (metallic) is a natural element and does not break down in the environment. Copper (metallic) will not move from the treatment area into the air and therefore is not expected to move to non-treated sites via air. Copper (metallic) may move to non-treatment sites by ocean currents at increasingly lower concentrations as it moves further away from the treatment site. Copper is an essential trace element that is physiologically and nutritionally required by plants, mammals, and aquatic organisms and is especially important for aquatic invertebrates like shrimp, crab, and lobster. The measurement of the potential for copper to accumulate in plant and animal tissues as a result of the very small amounts released from the V2 Net netting material is not possible. Copper is not expected to accumulate in plant and animal tissues.

When copper (metallic) is used in accordance with the label directions, the risks to non-target organisms are acceptable. Risk mitigation measures are outlined under the Measures to minimize risk section.

Value considerations

What is the value of V2 Net?

V2 net resists the growth of aquatic biofouling organisms and can be used in fresh, brackish, and marine waters.

V2 Net provides effective resistance against aquatic biofouling organisms such as hydroids, barnacles, and mussels. This allows for a reduction in the frequency of net cleaning and maintenance cycles. The reduction of net cleaning events can reduce certain fish diseases associated with frequent cleaning, such as proliferative gill disease (PGD).

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 Copper Flake Technical and V2 Net to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures - Human health

The hazard signal words "WARNING – EYE IRRITANT" are required on the principal display panel of the labels for Copper Flake Technical and V2 Net label.

Key risk-reduction measures - Environment

Label statements indicating that the V2 Net is not to come into contact with any source of water other than in accordance with the directions for use on the product label are required. Label statements informing users of the toxicity of the V2 Net to aquatic organisms are required.

Next steps

Before making a final registration decision on copper (metallic) and V2 Net, Health Canada'sPMRA will consider any written comments received from the public in response to this consultation document up to 45 days from the date of publication (8 March 2024) of this document.

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 Health Canada makes its registration decision, it will publish a Registration Decision on copper (metallic) and V2 Net (based on the Science Evaluation of PRD2024-03). In addition, the test data referenced in PRD2024-03 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.