All pesticides pose some level of risk. A 'risk assessment' is the process for evaluating the risks and benefits of using a pesticide. It often requires a complex combination of data to complete.

Types of Risk Assessments

Several governmental and international organizations perform formal risk assessments about pesticides. For example, the World Health Organization evaluates potential cancer risks, risks from food residue, and risks to the environment. Some organizations consider only the hazards, the bad stuff that can happen. Some organizations consider the hazards and the likely exposure (routes and amounts) when evaluating risk. That makes it difficult to compare risk assessments from different agencies; they can be like apples and oranges.

In the United States, the EPA identifies the hazards and potential exposure(s) before calculating the overall risk. Two major types of pesticide risk assessments are human health and ecological health:

Human Health Risk Assessments look at possible health risks to humans who might be exposed to pesticides in water, food, air, and through other activities. This can include the use of pesticides at home and at work. The four steps of a human health risk assessment are: Hazard Identification, Dose-Response Assessment, Exposure Assessment, and Risk Characterization.

Ecological Risk Assessments look at how wildlife, plants, and water sources can be affected by a pesticide. They require data on plant and animal toxicity, as well as environmental fate. There are four phases of an ecological risk assessment: Planning, Problem Formulation, Analysis, and Risk Characterization.

Collecting Data

Most pesticides go through extensive chemical, health, and safety studies. This must be done before a pesticide can be sold and used in the United States. Depending on the type of product, the EPA may review many different types of studies to determine its risk. All submitted studies must adhere to a strict set of guidelines. These studies can include:

EPA pays close attention to human health studies. It is important to understand how people are exposed to a pesticide and any related health risks. Toxicity studies like these are performed on the active ingredients alone, and again on formulated products. “Formulated products” have all of the ingredients you would find in the container for sale.

EPA continually collects information on problems people report with pesticides and re-evaluates pesticides. Re-evaluations can lead to changes in the allowed uses of a pesticide or its removal from the market.

Additional Resources:

• Risk Assessments - Environmental Protection Agency (EPA)
• Risk Assessment Guidelines - Environmental Protection Agency (EPA)
• Reducing Pesticide Risk - Environmental Protection Agency (EPA)
• Pesticide Tolerance Reassessment and Reregistration - Environmental Protection Agency (EPA)
• Ecological Risk Assessments - Environmental Protection Agency (EPA)
• Assessing Human Health Risk – California Department of Pesticide Regulation (CDPR)

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email at npic@ace.orst.edu.