Proposed Re-evaluation Decision PRVD2016-20, Imidacloprid


The online consultation is now closed.

Pest Management Regulatory Agency
23 November 2016
ISSN: 1925-0967 (PDF version)
Catalogue number: H113-27/2016-20E-PDF (PDF version)

UPDATE: As of 13 February 2017, the consultation period has been extended. Interested parties are encouraged to provide comments and suggestions by 23 March 2017.


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 Re-evaluation Decision PRVD2016-20, Imidacloprid please contact our publications office.

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


Table of Contents

Executive Summary

Health Canada's Pest Management Regulatory Agency (PMRA)

Health Canada's primary objective in regulating pesticides is to protect Canadians' health and their environment. Pesticides must be registered by Health Canada's Pest Management Regulatory Agency (PMRA) before they can be imported, sold, or used in Canada. Pesticides must go through rigorous science-based assessments before being approved for sale in Canada.

All registered pesticides must be re-evaluated by the PMRA on a cyclical basis to make sure they continue to meet modern health and environment safety standards and continue to have value. This may happen even sooner if new information becomes available. Re-evaluations may result in:

  • changes to how products are used;
  • changes to product labels to meet current health and environmental standards; or,
  • removing products from the market to prevent future harm to health or the environment.

Re-evaluation of Imidacloprid

Imidacloprid is a neonicotinoid insecticide used by commercial applicators and growers to manage insects on a large number of agricultural crops, trees and turf. It can also be used at home to manage insects on lawns, as well as fleas or ticks on cats and dogs.

When conducting the re-evaluation of imidacloprid, the PMRA reviewed scientific information provided by pesticide manufacturers, provinces and Environment and Climate Change Canada, as well as published scientific information. For the environmental assessment, potential risks to organisms on land and in water were examined. Risks to bees and other pollinators were not a part of this re-evaluation, as they are part of an ongoing pollinator risk assessment (see Re-evaluation Note REV2016-05, Re-evaluation of Imidacloprid - Preliminary Pollinator Assessment for more details). For the human health assessment, the following routes of exposure were examined: food, drinking water, exposure when applying the pesticide, and coming into contact with the pesticide after it has been applied.

Key Findings

The environmental assessment showed that, in aquatic environments in Canada, imidacloprid is being measured at levels that are harmful to aquatic insects. These insects are an important part of the ecosystem, including as a food source for fish, birds and other animals. Based on currently available information, the continued high volume use of imidacloprid in agricultural areas is not sustainable.

The environmental assessment also found that there is a potential risk to birds and small mammals from feeding on seeds that are treated with imidacloprid, however, it is expected that good agricultural practices and equipment could reduce this type of exposure.

The health assessment did not identify human health concerns from any exposure route when used according to current label standards.

Next Steps

For the protection of the environment, PMRA is proposing to phase-out all the agricultural and a majority of other outdoor uses of imidacloprid over three to five years. PMRA will consider alternate risk management proposals, provided that they can achieve acceptable levels in the environment in the same timeframe.

The proposed re-evaluation decision is now open for public consultation for 90 days from the date of Proposed Re-evaluation Decision PRVD2016-20, Imidacloprid. PMRA is inviting the public to submit comments on the proposed re-evaluation decision for imidacloprid including proposals that may refine the risk assessment and risk management. Once PMRA considers the comments and any information that are received during the public consultation period, it will publish a final decision.


What Is the Proposed Re-evaluation Decision for Imidacloprid?

The evaluation determined that under current conditions of use, the environmental risks for most products containing imidacloprid do not meet current safety standards. Therefore, the PMRA is proposing to cancel the following uses:

Products used by commercial applicators and growers for:

  • trees (except when applied as a tree trunk injection)
  • greenhouse uses
  • outdoor agricultural uses (including ornamentals)
  • commercial seed treatment uses
  • turf (such as lawns, golf courses, and sod farms

Products used at home for:

  • lawns

An evaluation of the scientific information has determined that certain uses of imidacloprid products have value and do not pose risks to human health or the environment. These uses include:

Products used by commercial applicators for:

  • use in and around structures (such as homes and buildings)
  • trees when applied as a tree trunk injection

Products used at home for:

  • flea, tick and lice treatment on cats and dogs

Before making a final re-evaluation decision on imidacloprid, the PMRA will accept and consider written comments on this proposal received up to 90 days from the date of this publication (Proposed Re-evaluation Decision PRVD2016-20, Imidacloprid). Please forward all comments to Publications. The PMRA will consider any additional data/information submitted during the consultation period in the final decision.

After the final re-evaluation decision is made, any required changes to the use-pattern will be implemented within three years. For any uses requiring phase out where there are no suitable alternative products, a phase-out period of up to five years, from the date of the final decision, may be considered to allow time for the development of alternative products. PMRA will be consulting agricultural producers and other stakeholders to consider the availability of suitable alternatives.

What Does Health Canada Consider When Making a Re-evaluation Decision?

Under the Pest Control Products Act, all registered pesticides must be re-evaluated by the PMRA on a cyclical basis to make sure they continue to meet modern health and environmental safety standards and continue to have value. The re-evaluation considers data from pesticide manufacturers, published scientific reports, information from other regulatory agencies and other available, relevant information. To reach its decisions, the PMRA applies internationally accepted hazard and risk assessment methods and modern risk management approaches and policies.

For more information on how the PMRA regulates pesticides, as well as the assessment process, please visit the Pesticides and Pest Management portion of Health Canada's website.

What is Imidacloprid?

Imidacloprid is a neonicotinoid insecticide registered to manage insects on a large number of agricultural crops including cereals and grains, legumes, pulses (beans, chickpeas, lentils and peas), oilseeds and horticultural crops, specialty crops and on Christmas trees, ornamentals, turf, forestry/woodlots, indoor and outdoor structural sites, and pets. It is applied using ground, aerial and seed treatment equipment, tree injection applicators, bait stations and spot-on applicators to cats and dogs.

Environmental Considerations

Can Approved Uses of Imidacloprid Affect the Environment?

Imidacloprid breaks down slowly in soil and tends to move into water, where it poses risks of concern to aquatic insects. Risks of concern have also been identified for soil dwelling organisms, beneficial arthropods, birds, and small, wild mammals.

Based on its chemical properties, when it is released into the environment, imidacloprid is expected to break down slowly in soil and move into surface water and groundwater. This has been confirmed by available monitoring data which shows that imidacloprid is being detected frequently in Canadian surface and groundwater.

Imidacloprid is not likely to accumulate in the tissues of organisms such as fish. As imidacloprid eventually breaks down further in the environment, the resulting break-down products are not expected to be a concern to terrestrial and aquatic life.

Risks of concern were identified for aquatic insects.

In aquatic environments, exposure to imidacloprid from spray drift and from runoff may result in toxic effects to aquatic insects. Imidacloprid is not expected to pose a direct risk to fish, amphibians, algae or aquatic plants.

The aquatic risk assessment relied on the results of environmental modelling in conjunction with Canadian water monitoring information. Environmental modelling predicted levels of imidacloprid in aquatic environments that would be expected to pose risks to aquatic invertebrates, including aquatic insects. Robust environmental monitoring from several areas of intense agricultural activity in Ontario and Quebec further support these findings as imidacloprid is detected frequently in surface water at levels well above concentrations that may result in toxic effects to insects. These regions include both outdoor mixed agricultural uses (for example, potatoes and vegetables) as well as greenhouse uses, where imidacloprid can be applied to seeds, plants or soil (in other words, as a seed treatment, spray application, or soil application). The risks to freshwater insects cannot be attributed to a specific crop or application method. Although robust monitoring data are not available for all regions in Canada, given the chemical properties of imidacloprid, it is anticipated that elevated levels may be found in many agricultural areas where there is a high volume of use. For these reasons, the PMRA cannot exclude any particular crop from risk management based on the available information. Monitoring data likely provide an underestimate of actual exposure, as sampling typically does not capture peak concentrations.

In terrestrial environments, imidacloprid poses a potential risk to soil dwelling organisms, beneficial arthropods, birds and small, wild mammals.

In terrestrial environments, imidacloprid poses a potential risk to soil dwelling organisms and beneficial arthropods. This risk triggers a requirement for precautionary label statements.

The ingestion of seed treated with imidacloprid may pose a risk to birds and small mammals. For some types of seeds, ingestion of a small number of seeds could result in toxic effects in birds and mammals. However, there is uncertainty whether or not certain treated seeds would be an attractive food source for birds and mammals. Risk mitigation measures include requirements to incorporate or remove any spilled or exposed treated seed from the soil surface to help reduce exposure.

The environmental assessment indicates that the continued use of imidacloprid in agricultural areas is not sustainable.

Precautionary label statements are currently on all product labels to reduce the potential for runoff to adjacent aquatic habitats. In addition, there are label restrictions prohibiting release of imidacloprid from greenhouses into surface waters. Despite these current label statements, levels of imidacloprid posing a risk to aquatic insects have been found in Canadian surface waters where imidacloprid is used for pest management in agriculture (including greenhouses).

Given the risks that have been identified and considering the available information, effective risk mitigation through a use-reduction strategy would be difficult to achieve for several reasons. It would be difficult to identify the specific uses that are causing the elevated levels in water given that much of the water monitoring data were from mixed-use areas of agriculture. In addition, it is not possible to accurately predict how much use reduction would be necessary to achieve acceptable levels of imidacloprid in the environment and, therefore, any use-reduction strategy would require extensive and comprehensive water monitoring information to confirm that risk reduction targets are being achieved. It is also not possible to estimate how long a reduction in environmental levels would take. In addition, in sectors where imidacloprid is approved for use but not currently used extensively, intensification of use in the future may lead to additional risks of concern. Given the above, phase-out of all outdoor agricultural, ornamental, turf, and tree uses (except tree injection uses) and greenhouse uses of imidacloprid is being proposed.

Health Considerations

Can Approved Uses of Imidacloprid Affect Human Health?

It is unlikely that use of imidacloprid will affect your health when used according to the label directions.

Potential exposure to imidacloprid may occur through diet (food and water), when handling and applying products containing imidacloprid or by entering areas that have been treated. 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. For pesticide regulation, the acceptable level of exposure to humans is set to at least one hundred times lower than the level at which no effects in animal testing were observed. The risk assessment also takes into consideration the exposure of vulnerable populations such as children and nursing mothers.

For the re-evaluation, acute, short, and long term (lifetime) animal toxicity tests from pesticide manufacturers, as well as information from published scientific literature were assessed for the potential of imidacloprid to cause health effects (including effects on the brain, immune system, reproduction system, and human development, and the potential to cause cancer). There was no indication that young animals were more sensitive to health effects than adult animals. The risk assessment protects against the effects observed in animal studies by ensuring that the level of human exposure is well below the lowest level at which these occurred.

Dietary risks from food and water are not of concern.

The dietary assessment took into consideration the potential for exposure to imidacloprid residues in food and drinking water for the general population and different subpopulations, including children and women of reproductive age. No risks of concern were identified.

Risks from use at home or to bystanders are not of concern when used according to label directions.

People may potentially be exposed when applying imidacloprid to pets for flea and tick treatments (or handling a pet afterwards) or to lawns and turf. Visiting residential or recreational areas treated with imidacloprid (includes parks, indoor environments, and golf courses) can also result in potential exposure. Incidental oral exposure may also occur for children playing in treated areas. No risks of concern were identified for these exposure routes.

When potential exposure in and around homes was combined with potential dietary exposure (food and drinking water), this did not result in risks of concern.

Occupational risks to handlers are not of concern when products are used according to the label directions.

No risks of concern were identified for workers involved in mixing, loading, applying, and handling product, when modern engineering and/or personal protective equipment are in place.

Postapplication risks are not of concern when products are used according to the label directions.

No risks of concern were identified for workers involved in postapplication activities such as working in treated sites or handling treated seed if modern protective measures are used including closed cab equipment.

Based on the human health assessment, the PMRA is proposing updates to product labels for the protection of workers and bystanders to meet current health standards.

Value Considerations

What is the Value of Imidacloprid?

Imidacloprid is approved for use on a wide range of agricultural crops in the grains and oilseeds and horticultural sectors, although the amount actually being used on each crop varies considerably. For some crops it is the only approved insecticide for specific pests, whereas for most crops there are alternative insecticides approved for use. Further, it has value as a seed treatment due to the limited number of registered seed treatments to manage the same pest and site combinations. In addition, imidacloprid provides a pest management tool for important insect pests of trees when applied as a tree injection (for example emerald ash borer).

With respect to alternatives, there are new insecticides that have been submitted for approval by manufacturers that may serve as replacements in some cases, or approved insecticides that may be expanded for use. Some of these insecticide alternatives may have cost implications, be less effective against specific pests, or be under re-evaluation themselves.

International Regulatory Status of Imidacloprid

The PMRA routinely works collaboratively with other member countries in the Organisation for Economic Co-operation and Development (OECD) on the regulation of pesticides. As part of the re-evaluation of an active ingredient, the PMRA takes into consideration recent developments and new information on the status of a pesticide in other jurisdictions. Imidacloprid is currently acceptable for use in many OECD member countries, including Australia, New Zealand and the United States. Canada and the United States are collaborating on the re-evaluation of the neonicotinoids, including imidacloprid, to assess potential risks to pollinators.

In Europe, substantial use restrictions for imidacloprid (and other neonicotinoid products) have been imposed to minimize exposure to bees while an assessment of pollinator risk is completed. Additional environmental risk assessment work continues in Europe. Provincial, state, and member state level restrictions on neonicotinoid use have been imposed in some cases.

Next Steps

The PMRA is inviting the public to submit comments on the proposed re-evaluation decision for imidacloprid including proposals that may refine the risk assessment and risk management. Before making a final re-evaluation decision on imidacloprid, the PMRA will consider any comments received from the public in response to Proposed Re-evaluation Decision PRVD2016-20, Imidacloprid. The PMRA will then publish a Re-evaluation Decision, which will include the decision, the reasons for it, a summary of comments received on the proposed decision and the PMRA's response to these comments. Based on the final outcome of the re-evaluation, manufacturers will be expected to revise product labels to include new risk-reduction measures and/or phase-out uses according to the implementation schedule to be established by the PMRA.

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