Evaluation Report ERC2011-03, Confidor 200 SL containing Imidacloprid

This content was archived on June 24, 2013.

Pest Management Regulatory Agency
22 July 2011
ISSN: 1911-8082 (PDF version)
Catalogue number: H113-26/2011-3E-PDF (PDF version)

Summary

Table of Contents

• Registration Decision for Confidor 200 SL (Imidacloprid)
• What Does Health Canada Consider When Making a Registration Decision?
• What Is Imidacloprid?
• Health Considerations
• Environmental Considerations
• Value Considerations
• Measures to Minimize Risk
• What Additional Scientific Information Is Being Requested?
• Other Information

Registration Decision for Confidor 200 SL (Imidacloprid)

Health Canada's Pest Management Regulatory Agency (PMRA), under the authority of the  Pest Control Products Act and  Regulations, has granted conditional registration for the sale and use of BAY NTN 33893 Technical Insecticide and Confidor 200 SL, containing the technical grade active ingredient imidacloprid, for systemic control of insect pests on deciduous and coniferous trees.

An evaluation of available scientific information found that, under the approved conditions of use, the product has value and does not present an unacceptable risk to human health or the environment.

Although the risks and value have been found acceptable when all risk reduction measures are followed, the applicant must submit additional scientific information as a condition of registration.

This summary describes the key points of the evaluation, while the Science Evaluation of Evaluation Report ERC2011-03, Confidor 200 SL containing Imidacloprid provides detailed technical information on the human health, environmental and value assessments of BAY NTN 33893 Technical Insecticide and Confidor 200 SL.

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 (for example, those most sensitive to environmental contaminants). 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 the PMRA regulates pesticides, the assessment process and risk-reduction programs, please refer to the following:

• Protecting Your Health and the Environment
• Pesticide Registration Process
• Pesticide Risk Reduction Program

What Is Imidacloprid?

Imidacloprid is a neonicotinoid insecticide that is readily taken up by plants and translocated systemically within the plants. It is active against insects on contact and through ingestion. Various end-use products containing imidacloprid are currently registered for control of insect pests in turf, on various food crops or on companion animals (dogs or cats). Registered uses on plants include foliar sprays, seed treatments and application to soil for uptake by plant roots.

Health Considerations

Can Approved Uses of Imidacloprid Affect Human Health?

Imidacloprid is unlikely to affect your health when used according to label directions.

Potential exposure to imidacloprid may occur when handling and applying Confidor 200 SL. When assessing health risks, two key factors are considered:

• the levels at which no health effects occur in animal testing and
• the levels to which people may be exposed.

The dose levels used to assess risks are established to protect the most sensitive human population (for example, children and nursing mothers). Only those 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. The health effects noted in animals occur at doses more than 100 times higher (and often much higher) than levels to which humans are normally exposed when products are used according to label directions.

The active ingredient imidacloprid is of high toxicity when given as a single oral dose to rats. Consequently, the words "Danger Poison" are required on the label for the active ingredient.

Imidacloprid did not cause cancer in animals and did not alter genetic material. There was also no indication that imidacloprid impaired reproductive ability. Health effects in animals given daily doses of imidacloprid over long periods of time included effects on the liver, kidney, thyroid gland and eyes. There was evidence that imidacloprid affected the nervous system. When imidacloprid was given to pregnant animals, effects on the developing fetus were observed at doses that were toxic to the mother, indicating that the fetus is not more sensitive to imidacloprid than the adult animal. The risk assessment protects against these effects by ensuring that the level of human exposure is well below the lowest dose at which these effects occurred in animal tests.

Risks in Residential and Other Non-Occupational Environments

Potential exposure and risks to bystanders are expected to be negligible if label directions and precautionary measures are followed.

For bystanders, the exposure is expected to be much less than that for workers and is considered negligible. Therefore, health risks to bystanders are not of concern.

Occupational Risks From Handling Confidor 200 SL

Occupational risks are not of concern when Confidor 200 SLis used according to the label directions, which include protective measures.

Commercial applicators, including city employees, who mix, load or apply Confidor 200 SL by a pressurized tree-trunk injector system have the potential for intermittent dermal and/or inhalation exposure from April to September. Therefore, the label specifies that Confidor 200 SL must only be used with closed application systems and anyone mixing/loading and/or applying Confidor 200 SL must wear a long-sleeved shirt, long pants and chemical-resistant gloves during mixing, loading, application, cleaning and repair, and during removal of injection devices from trees. The label also requires that the application sites are not left unattended during the treatment process and applicators must ensure that there is no leakage from the plugged injection holes of host trees after application.

Taking into consideration these label requirements and the expectation of the exposure period for handlers and workers, the risk to these individuals are not a concern.

Environmental Considerations

What Happens When Imidacloprid Is Introduced Into the Environment by Trunk Injection?

In comparison to traditional application methods, trunk injection is expected to reduce environmental exposure. Risk-reduction measures have been implemented to mitigate effects on pollinators that may visit the blossoms of treated trees.

Imidacloprid and its degradates move primarily to the fast growing parts of the tree such as the shoots and leaves. Some residues will also reach other plant parts such as blossoms and buds. Without risk-reduction measures, imidacloprid may impact non-target pollinators, such as bees, foraging on the blossoms of treated trees. At the proposed rate, imidacloprid is not expected to pose a risk to other non-target species.

In comparison to traditional application methods, trunk injection is expected to reduce environmental exposure since imidacloprid is injected directly into selected trees.

Value Considerations

What Is the Value of Confidor 200 SL?

When injected into the trunks of trees, Confidor 200 SL can provide control of various foliage-feeding insect pests and can provide control or suppression of wood-boring beetles.

Confidor 200 SL applied as an injection into the trunks of trees reduces populations of foliage-feeding insect pests below levels that are damaging to the trees. It may also reduce populations of wood-boring beetles substantially, although these pests are more difficult to control and have lower tolerable damage thresholds. Confidor 200 SL provides a new alternative active ingredient for control of foliage-feeding pests of trees and the first pest control product registered for use against wood-boring beetles in Canada. Application by trunk injection helps conserve natural enemies of pests as well as other non-target organisms that would be exposed to foliar applications of insecticides.

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 Confidor 200 SL to address the potential risks identified in this assessment are as follows.

Key Risk-Reduction Measures

Human Health

Because there is a concern with workers or bystanders coming into direct contact with Confidor 200 SL on the skin, by inhalation or through ingestion, anyone mixing, loading and applying Confidor 200 SL must: 1) use only closed application systems and 2) wear a long-sleeved shirt, long pants and chemical-resistant gloves during mixing, loading, application, cleaning and repair, and during removal of injection devices from trees. The label also requires that the application sites are not left unattended during the treatment process. Applicators must ensure that there is no leakage from the plugged pre-drilled holes of host trees after application.

Environment

For trees that may be visited by pollinators, the label restricts the timing of applications to mitigate the risk to pollinators. Furthermore, the uses are restricted to licensed pest control operators authorized with permits or appropriate license by the government in conjunction with a federal, provincial or municipal-government control program.

What Additional Scientific Information Is Being Requested?

Although the risks and value have been found acceptable when all risk-reduction measures are followed, the applicant must submit additional scientific information as a condition of registration. More details are presented in the Science Evaluation of Evaluation Report ERC2011-03, Confidor 200 SL containing Imidacloprid or in the section 12 Notice associated with these conditional registrations. The applicant must submit the following information by September 1, 2013.

Environment

• Canadian monitoring data on imidacloprid and its transformation products in various parts of treated trees over time, which includes samples of nectar, pollen, guttation water and resinous substances
• Additional information on bee foraging behaviour on blooming trees

Other Information

As these conditional registrations relate to a decision on which the public must be consulted, the PMRA will publish a consultation document when there is a proposed decision on applications to convert the conditional registrations to full registrations or on applications to renew the conditional registrations, whichever occurs first.

The test data cited in Evaluation Report ERC2011-03, Confidor 200 SL containing Imidacloprid (namely, the test data relevant in supporting the registration decision) will be made available for public inspection when the decision is made to convert the conditional registrations to full registrations or to renew the conditional registrations (following public consultation). If more information is required, please contact the PMRA's Pest Management Information Service.