Proposed Re-evaluation Decision PRVD2016-09, Iprodione

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The online consultation is now closed.

Pest Management Regulatory Agency
17 March 2016
ISSN: 1925-0967 (PDF version)
Catalogue number: H113-27/2016-9E-PDF (PDF version)


UPDATE: As of 18 May 2016, the consultation period has been extended. Interested parties are encouraged to provide comments and suggestions by 15 July 2016.

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 PRVD2016-09, Iprodione please contact our publications office.

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


Table of Contents

General Introduction

In Canada, pesticides are regulated under the Pest Control Products Act, administered by Health Canada's Pest Management Regulatory Agency (PMRA). All pesticides are registered (i.e. approved) if a rigorous scientific assessment indicates that the health and environmental risks are acceptable and the products have value. The Pest Control Products Act also contains provisions for post-market reviews of registered pesticides namely, re-evaluation and special reviews, to assess whether pesticides continue to meet Health Canada's health and environmental standards, and whether they can continue to be used in Canada.

As part of the decision making process, before making a final decision, the PMRA consults with the members of the public and other interested stakeholders on all proposed major decisions such as new registrations, re-evaluations and special reviews. The PMRA encourages the public and stakeholders to participate in the consultation process. The proposed decisions are made based on the information available at the time, and the PMRA will consider the comments and information received during consultation using a science-based approach before making a final decision. The final decision will be published on the Pesticides and Pest Management portion of Health Canada's website and it will include a summary of the comments received during the consultation and PMRA's responses to the comments.

The registration status of products and conditions of use of pesticide products on the market are not impacted by proposed re-evaluation or special review decisions. This may be the case only when final decisions are made. However, at any point during the re-evaluation or special review of a pesticide, the Pest Control Products Act allows the PMRA to cancel or amend the registration of registered pest control products, if there are reasonable grounds to believe this is necessary to deal with a situation that endangers human health or safety or the environment.

Proposed Re-evaluation Decision for Iprodione

An evaluation of available scientific information has determined that under the currently labelled conditions of use, the human health risks estimated for iprodione do not meet current standards. Therefore, the cancellation of all iprodione usesis proposed at this time. Consideration of any additional data/information submitted during the consultation period to further refine the health risk assessment may or may not result in a change to this proposal.

This Proposed Re-evaluation Decision is a consultation document that summarizes the science evaluation for iprodione and presents the reasons for the proposed re-evaluation decision.

The information in Proposed Re-evaluation Decision PRVD2016-09, Iprodione is presented in two parts. The Overview describes the regulatory process and key points of the evaluation, while the Science Evaluation provides details on the risk assessments conducted for iprodione.

The PMRA will accept written comments and data/information up to 90 days from the date of publication of Proposed Re-evaluation Decision PRVD2016-09, Iprodione. Please forward all comments on PRVD2016-09 to Publications.

What Does Health Canada Consider When Making a Re-evaluation 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 conditions or proposed conditions of registration. The Act also requires that products have value when used according to the label directions. Requirements of registration may include precautionary measures on the product label to further reduce risk.

To reach its decisions, the PMRA applies hazard and risk assessment methods as well as policies that are rigorous and modern. These methods consider the unique characteristics of sensitive subpopulations in both humans (for example, children) and 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 present when predicting the impact of pesticides. For more information, please refer to the following:

Before making a re-evaluation decision on iprodione, the PMRA will consider any comments/information received from the public in response to Proposed Re-evaluation Decision PRVD2016-09, Iprodione. The PMRA will then publish a Re-evaluation Decision document on iprodione, which will include the decision, the reasons for it, a summary of comments received on the proposed registration decision and the PMRA's response to these comments.

For more details on the information presented in this summary, please refer to the Science Evaluation part of Proposed Re-evaluation Decision PRVD2016-09, Iprodione.

What is Iprodione?

Iprodione is a contact fungicide with protective and curative action. It works by inhibiting the germination of spores and growth of fungal mycelium. In Canada, it is used to control a broad range of fungal pathogens on a wide variety of greenhouse, orchard and field crops, ornamentals and on turf. It is applied using ground and aerial application equipment by farmers, greenhouse and nursery workers, and professional applicators.

Health Considerations

Can Approved Uses of Iprodione Affect Human Health?

Risk concerns were identified from food and drinking water exposure to iprodione.

Potential exposure to iprodione may occur through the diet (food and water), when handling and applying products containing iprodione or by entering treated sites. 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 exposure is well below levels that cause no effects in animal testing are considered acceptable for continued 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, iprodione was of slight acute toxicity by the oral route while dermal and inhalation exposure resulted in low acute toxicity. It was a mild eye irritant but not irritating to the skin. Iprodione did not produce an allergic skin reaction.

Registrant-supplied short, and long term (lifetime) animal toxicity tests, as well as numerous peer-reviewed studies from the published scientific literature were assessed for the potential of iprodione to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. The most sensitive endpoints used for risk assessment included changes in weights of some endocrine organs and impaired male sexual development. An increased incidence in several tumor types was observed in rats and mice following long-term dosing with iprodione. There was no indication that the young were more sensitive than the adult animal. The risk assessment takes these and any other potential effects into account in determining the allowable level of human exposure to iprodione.

Residues in Water and Food

Dietary risks from food and water are of concern. In order to address these concerns, all registered uses considered in the dietary exposure and risk assessment are proposed for cancellation unless there is information/data submitted during the consultation period that would alter the risk assessment.

Reference doses define levels to which an individual can be exposed over a single day (acute) or lifetime (chronic) and expect no adverse health effects. Generally, dietary exposure from food and water is acceptable if it is less than 100% of the acute reference dose or chronic reference dose (acceptable daily intake). For the cancer assessment, a lifetime cancer risk that is less than one-in-a-million (1 × 10-6) is generally considered an acceptable risk for the general population when exposure occurs through pesticide residues in/on food and drinking water, and to otherwise unintentionally exposed persons.

Potential exposure was estimated from residues of iprodione and relevant metabolites in both treated crops and drinking water. Exposure to different subpopulations, including children and women of reproductive age, were considered. Food residue estimates were based mostly on surveillance data and included percent crop treated information and chemical-specific processing factors when available. Drinking water estimated environmental concentrations (EECs) were based on the modelling of iprodione residues in groundwater. Different EECs were determined using the typical use rates for turf, orchard or canola applications.

Acute and chronic (non-cancer) exposures from iprodione in food and drinking water were below the acute reference dose (ARfD) and ADI for most population groups at the use rates assessed. However, the cancer risk exceeded 1 × 10-6 for the general population for all use rates assessed and is of concern. The estimated cancer risks ranged from 3 × 10-6 to 5 × 10-5. Exposure from drinking water was the major risk contributor in the cancer assessment. Exposure from food commodities was also a significant contributor in the assessment with an estimated cancer risk of 1 × 10-6. The exposure and risk from food commodities is largely attributed to residues in/on imported South American stone fruits.

Canadian MRLs for iprodione are currently specified for a wide range of commodities. Where no specific MRL has been established, a default MRL of 0.1 ppm applies, which means that pesticide residues in a food commodity must not exceed 0.1 ppm. The current MRLs for iprodione are listed in Appendix VII of the Science Evaluation of PRVD2016-09, Iprodione. The revocation of all established MRLs is proposed to reduce dietary risk and to align with the proposed decision to cancel all registered uses in Canada.

Risks in Residential and Other Non-Occupational Environments

Non-occupational risks are not of concern.

There are currently no registered residential uses of iprodione; as such a risk assessment for a residential handler was not required.

Agricultural application of iprodione may result in spray drift. Studies that sampled the air in agricultural areas in the United States and Europe during the spray season indicate that iprodione can be present in ambient air. Risk estimates based on the highest level of iprodione measured in the air resulted in non-cancer and cancer risk assessments that are not of concern.

Agricultural application of iprodione may result in iprodione residues in homes. Studies that sampled dust, floors, and clothing indicate that there is potential for incidental exposure for children. Risk estimates based on the highest level of iprodione measured in homes resulted in non-cancer and cancer risk assessments that are not of concern.

Commercial application of iprodione to golf courses could lead to exposure for people golfing. Risk estimates for golfers resulted in non-cancer and cancer risk assessments that are not of concern.

Aggregate risk estimates where exposure from food and drinking water are combined with possible bystander exposure were not conducted due to cancer concerns with food and drinking water.

A cumulative assessment was not required at this time.

Occupational Risk to Mixer/Loader/Applicator and Postapplication Workers

Occupational (mixer/loader/applicator) risks are of concern for some uses when products are used according to the current label directions, but can be mitigated.

Risks for farmers and workers who mix, load and apply iprodione for agricultural crops (fruits and vegetables, ornamentals, canola, alfalfa and turf) are of concern for some scenarios. However, they can be effectively mitigated using additional personal protective clothing and engineering controls (such as water soluble packaging, protective headgear and/or closed cabs).

Risks for farmers and workers who treat canola and mustard seed or potato seed pieces are of concern for some scenarios when used according to the current label directions. However, they can be effectively mitigated using additional personal protective clothing and engineering controls (such as closed mix, load and transfer systems).

Adequate data were not available to assess exposure from the use of iprodione in commercial garlic bulb dipping facilities, or in greenhouses when using hand-held mistblowers or foggers.

Occupational postapplication risks are of concern for most uses when products are used according to the current label directions, and mitigation may not be agronomically feasible.

Postapplication occupational risk assessments consider exposure to workers entering treated sites in agriculture and other scenarios. Based on the precautions and directions for use on the current product labels, most postapplication risks to workers performing activities such as thinning, pruning and harvesting of crops are of concern. Occupational postapplication risks can be mitigated by revising the restricted-entry intervals (REIs). The REIs proposed to mitigate post application risk range from 1 to 137 days and therefore, may not be agronomically feasible.

Postapplication risk may also be of concern to workers who plant treated seeds (such as canola, mustard, and carrot). However, they can be effectively mitigated using additional engineering controls (such as closed cab planting).

Environmental Considerations

What Happens When Iprodione Is Introduced Into the Environment?

When used according to label directions, iprodione is not expected to pose an unacceptable risk to the environment.

When iprodione is released into the environment some of it can be found in soil and surface water. In the terrestrial environment, iprodione is expected to break down in the presence of soil microbes and is not very persistent. Depending on the soil type, it takes microbes from 2 weeks to 6 months to break down half of the iprodione present in soil. In the aquatic environment, iprodione is also broken down by microbes, but much more rapidly than in soil. When iprodione is applied to soil it is not expected to leach into groundwater, but under sandy soil conditions it has the potential to move downward through the soil profile and potentially enter groundwater. Iprodione has not been detected in surface or groundwater; however, Canadian monitoring data for iprodione is limited. Iprodione is not expected to enter the atmosphere and be transported long distances from where it is used. Iprodione is not likely to accumulate in the tissues of organisms such as fish.

Iprodione is found to be toxic to bees, beneficial arthropods, birds, small wild mammals and aquatic organisms when exposed to high enough concentrations. Consequently, if iprodione is used at labelled application rates without any risk reduction measures, it may cause adverse effects in the organisms listed above. Therefore, risk mitigation measures, in the form of use restrictions and precautionary label statements would minimize exposure and mitigate potential risks. The risk to aquatic organisms would be mitigated with spray buffer zones and recommendations on the label to reduce runoff from fields. Hazard statements would inform users of the toxicity of iprodione to beneficial insects and mammals.

Value Considerations

What is the Value of Iprodione?

Iprodione is used to control several economically important fungal diseases on a wide variety of food and non-food sites, including significant uses on large crops like canola and intensively managed sites such as turf.

Iprodione is registered in Canada for the control of many economically important fungal diseases on several field, orchard, nursery and greenhouse crops and ornamentals, conifer seedlings and turf (in other words, 24 crops, 53 ornamentals and turf against 24 fungal pathogens). Particularly important uses of iprodione include: foliar treatments to control Sclerotinia stem rot and Alternaria black spot on canola; and brown and Fusarium patch, leaf spots, snow moulds and dollar spot on turf.

Iprodione is effective as a protective and curative fungicide. Because of these properties, it can be used as a tank-mix partner or as a rotational fungicide with fungicides from other chemical groups in an integrated pest management (IPM) program to manage development of resistance in pathogens.

Measures to Minimize Risk

The PMRA has assessed the available information and concluded that the use of iprodione and associated end-use products in accordance with the label poses potential risks of concern to human health. Specifically, potential health risk concerns were identified from exposure to iprodione in food and drinking water and from exposure to occupational workers under certain use scenarios. Therefore, the PMRA is proposing to cancel all uses of iprodione in Canada.

What Additional Scientific Information Is Being Requested?

As the PMRA is proposing cancellation of all uses of iprodione, no additional data will be required under section 12 of the Pest Control Products Act.

Next Steps

Before making a final re-evaluation decision on iprodione, the PMRA will consider any comments received from the public in response to Proposed Re-evaluation Decision PRVD2016-09, Iprodione. The PMRA will then publish a Re-evaluation Decision document that will include the decision, the reasons for it, a summary of comments received on the proposed decision and the PMRA's responses to these comments.

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