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Approving Pesticides for Use:
Understanding Pesticide Registration and Reregistration

Why are pesticides registered and reregistered?

Pesticide Registration

All pesticides sold or distributed in the United States must be registered by the U.S. Environmental Protection Agency (EPA), based on scientific studies showing that they can be used without posing serious risks to people or the environment. The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires EPA to review all the scientific data on a pesticide's ingredients, uses, and exposure. EPA then estimates the potential risks of using the pesticide to human health or the environment. If these are acceptable risks, then EPA approves the pesticide for registration.

Pesticide Reregistration

Because of advances in scientific knowledge, FIFRA also requires that pesticides first registered before November 1984 be reregistered. The reregistration process ensures that older pesticides meet current health and safety standards. The process involves a complete review of all the old and new scientific data on a pesticide. Based on this review, EPA reassesses the risks of using the pesticide, determines if any more data is needed on its effects on human health or the environment, and determines whether more regulation is needed. EPA may require the manufacturer to perform risk reduction measures. Once any necessary actions are taken, EPA approves the pesticide for reregistration.

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What is tolerance reassessment?

New safety standards require EPA to reassess pesticide tolerances, the total amount of pesticide residue that can be left on foods that have been treated with pesticides. The 1996 Food Quality Protection Act (FQPA) created new regulatory standards that EPA must consider for tolerance reassessment. EPA must consider:

  • All pesticide exposure from food, drinking water, and home and garden use
  • Special sensitivity of infants and children to pesticides
  • Cumulative effects of a group of pesticides thought to affect the body in the same way (pesticides with common mechanisms of toxicity)

Once these standards are taken into consideration, EPA determines allowable levels of pesticides that can be left on foods. Tolerance reassessment is an important part of the reregistration process.

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What are RED, IRED, and TRED documents?

When EPA completes a pesticide reregistration or tolerance reassessment, it issues one of three risk management decision documents. These are known as Reregistration Eligibility Decision (RED), Interim Reregistration Eligibility Decision (IRED), or Tolerance Reassessment Progress and Risk Management Decision (TRED) documents.

RED (Reregistration Eligibility Decision)
When a pesticide is approved for reregistration, EPA explains the basis for its decision in an RED document. RED documents are issued for most pesticides. An RED summarizes EPA's risk assessment and outlines any risk reduction measures needed for a pesticide to be reregistered.

IRED (Interim Reregistration Eligibility Decision)
IRED documents are issued for some pesticides undergoing reregistration that are part of a group of pesticides thought to affect the body in the same way (pesticides with common mechanisms of toxicity). FQPA requires that the cumulative effects of these pesticides be assessed. EPA issues an IRED when an individual risk assessment is completed for a single pesticide. Once a cumulative risk assessment is completed, a final RED is issued for each pesticide in the group. To determine cumulative risks, EPA evaluates the potential for people to be exposed to more than one pesticide at a time. EPA considers exposure from food, drinking water, and home and garden use.

TRED (Tolerance Reassessment Progress and Risk Management Decision)
For some pesticides undergoing tolerance reassessment, EPA issues TRED documents. While tolerance reassessment decisions are usually included with reregistration decisions in RED and IRED documents, TRED documents are issued for pesticides if:

  • FIFRA does not require a pesticide to be reregistered because it was first registered after November 1984
  • EPA completed reregistration for a pesticide before tolerance reassessment was required by FQPA in 1996
  • A pesticide is not registered in the United States, but its residue remains on foods imported from countries where the pesticide is used

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What information do RED, IRED, and TRED documents contain?

Each RED, IRED, and TRED document contains both the scientific data EPA has reviewed and EPA's own regulatory decision for a pesticide. Most RED and IRED documents include more information than TRED documents. RED and IRED documents provide a complete review of a pesticide for reregistration, while TRED documents include only the information concerning tolerance reassessment. RED and IRED documents are usually divided into six parts.

The introduction describes EPA's purpose and process of reregistration.

Case Overview
The case overview profiles the pesticide being reviewed, including its chemical properties, use and usage, and regulatory history.

Science Assessment
The science assessment includes all the scientific knowledge that EPA has reviewed for the pesticide. Scientific studies on the effects of pesticide exposure on human health or the environment are reviewed. Specific studies of the toxic and cancer-causing effects of pesticide exposure to test animals, like rats and mice, are used to assess human health risks. Studies on human pesticide exposure at work or at home are also reviewed. These risks are assessed by evaluating pesticide use, dietary exposure through food and drinking water, and total exposure from different sources. The science assessment also contains scientific studies on how the pesticide affects the environment. Studies on the pesticide's toxic effects to land and water animals, soil and water contamination, and other ecological risks are also reviewed.

Risk Management and Reregistration Decision
Based on its review of the scientific data, EPA outlines risk reduction measures required for reregistration and tolerance reassessment. Risk reduction measures that EPA may require for the pesticide include:

  • Voluntary cancellation of products or uses
  • Restricting use to certified applicators
  • Limiting the amount or frequency of use
  • Improving instructions and precautions
  • Requiring more protective clothing or equipment
  • Limiting treatment areas
  • Employing environmental safeguards

Actions Required of Registrants
Pesticide manufactures must perform risk reduction measures in order for the pesticide to be reregistered. Actions required may include changing product labels, changing tolerances and use, and collecting more data on exposure risks. The pesticide is officially reregistered once the manufacturer has completed these actions.

The appendices contain tables on pesticide use, references, and paperwork for the pesticide manufacturer.

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What information do fact sheets contain?

Fact sheets summarize the information found in RED, IRED, and TRED documents. Each fact sheet includes brief summaries of EPA's science review, risk assessment, risk reduction measures, additional data requirements, labeling changes, and final decision. Fact sheets accompany most, but not all, RED, IRED, and TRED documents.

Authored by
Devi Chandrasekaran, Student Research Assistant, and
Heather Dantzker, Research Associate