Evaluation Report ERC2015-01, Metofluthrin

Pest Management Regulatory Agency
7 December 2015
ISSN: 1911-8082 (PDF version)
Catalogue number: H113-26/2015-1E-PDF (PDF version)

This page is a summary of the Evaluation Report. If you would like more detail, please request the full Evaluation Report.

To obtain an electronic copy of the document, Evaluation Report ERC2015-01, Metofluthrin, please contact our publications office.

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


Table of Contents

Registration Decision for Compound Metofluthrin

Health Canada's Pest Management Regulatory Agency (PMRA), under the authority of the  Pest Control Products Act and  Regulations, granted conditional registration for the sale and use of SumiOne Technical Grade and OFF! Clip On Mosquito Repellent, containing the technical grade active ingredient metofluthrin, as a personal mosquito repellent.

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 ERC2015-01, Metofluthrin provides detailed technical information on the human health, environmental and value assessments of SumiOne Technical Grade and OFF! Clip On Mosquito Repellent.

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 on how the PMRA regulates pesticides, the assessment process and risk‑reduction programs, please refer to the following:

What Is Metofluthrin?

Metofluthrin is an active ingredient which belongs to the pyrethroid class of insecticides and is used to repel mosquitoes. OFF! Clip On Mosquito Repellent is a battery-powered device that contains a metofluthrin-impregnated cartridge. The OFF! Clip On Mosquito Repellent device is worn on the person and functions as a personal insect repellent by vaporising metofluthrin and emitting it over an area large enough to protect the wearer from mosquitoes.

Health Considerations

Can Approved Uses of Metofluthrin Affect Human Health?

OFF! Clip On Mosquito Repellent containing metofluthrin is unlikely to affect your health when used according to label directions.

Potential exposure to metofluthrin may occur when handling or using 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 dose levels used to assess risks are established to protect the most sensitive human population (for example, children and nursing mothers). 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. 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 pesticide-containing products are used according to label directions.

In laboratory animals, metofluthrin was of low acute toxicity by the oral and dermal routes of exposure. It was of slight acute toxicity by the inhalation route of exposure and as such the hazard statement "Caution Poison" is required on the label. Metofluthrin was minimally irritating to the eye, was nonirritating to the skin, and did not cause an allergic skin reaction. Metofluthrin does, however, belong to a class of pesticides that may cause a transient itching, tingling or burning sensation of the skin following skin contact.

OFF! Clip On Mosquito Repellent product consists primarily of metofluthrin; therefore, the toxicity profile and label statements for technical grade metofluthrin are representative of this product.

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 metofluthrin to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. The most sensitive endpoints for risk assessment included neurotoxicity characterized by clinical signs. In addition, although there was no evidence of increased susceptibility of the young in the guideline toxicity studies submitted, residual uncertainty remains since young animals have differences (such as the age-dependent maturation of key metabolic processes) that may lead to increased susceptibility of the young to pyrethroid toxicity. There was also evidence of effects on the liver. Longer-term dosing with metofluthrin resulted in liver tumours in rats, but not in mice. The risk assessment protects against the effects noted above by ensuring that the level of exposure to humans is well below the lowest dose at which these effects occurred in animal tests.

Risks in Residential Environments

Risk for residential exposure is not of concern provided that directions specified on the label are observed.

A risk assessment conducted for individuals handling, or those in the vicinity of the OFF! Clip On Mosquito Repellent device, indicated that risks to adults, youth and children are not of concern when the product is used according to label directions.

Environmental Considerations

What Happens When Metofluthrin Is Introduced Into the Environment?

OFF! Clip On Mosquito Repellent will not pose an unacceptable risk to nontarget aquatic and terrestrial organisms.

Metofluthrin enters the environment when used as an insect repellent in a personal device, which allows the active ingredient to vaporize into the air. Significant deposition of metofluthrin in the environment is unlikely due to the volatile nature of the compound, rapid transformation processes in soil, and limited use pattern.

Metofluthrin is highly toxic to aquatic invertebrates, fish, and bees. But the exposure of these nontarget organisms to metofluthrin is, however, unlikely based on the use pattern.

Value Considerations

What Is the Value of OFF! Clip On Mosquito Repellent?

OFF! Clip On Mosquito Repellent is a personal insect repellent device that provides protection from mosquitoes for up to 11 hours.

Mosquitoes are an outdoor nuisance pest across all of Canada, especially in the morning and evening. Mosquito bites can cause discomfort and irritation, and can vector diseases such as West Nile Virus and other encephalitis-causing viruses. In addition to health risks associated with mosquito bites, annoyance from mosquitoes can reduce the enjoyment of being outdoors and cause people to avoid outdoor activities when mosquito populations are heavy.

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 NUP6D 04 Herbicide to address the potential risks identified in this assessment are as follows.

Key Risk-Reduction Measures

Human Health

For OFF! Clip On Mosquito Repellent the hazard statement "Caution Poison" is required on the product label, as is the statement "only adults are permitted to replace the refill disk." In addition, a statement identifying that the device "should not be worn while barbecuing" is required.


Key risk-reduction measures for the protection of the environment include precautionary label statements:

  • Toxicity statement for bees;
  • Toxicity statement for aquatic organisms.

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 ERC2015-01, Metofluthrin or in the Section 12 Notice associated with these conditional registrations. The applicant must submit the following information within the time frames indicated.

Human Health

To further confirm the units of exposure and dermal absorption value used in the risk assessment, conditional registration of the OFF! Clip On Mosquito Repellent can be supported pending the submission of the following:

  • New passive dosimetry study to estimate the amount of metofluthrin deposited on the surface of the skin and the amount of the chemical available for inhalation through the use of appropriate trapping devices for both adults and children. The study must be done according to acceptable guidelines.
  • New in vivo dermal absorption study to estimate the dermal absorption of metofluthrin with longer monitoring periods to better determine the fate of the skin bound residues. The study must be done according to acceptable guidelines.

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 ERC2015-01, Metofluthrin (for example, 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 by phone (1-800-267-6315) or by e-mail (pmra.infoserv@hc-sc.gc.ca).

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