Studies on the health effects of pesticides are carried out on all pesticides before they are approved for use in the European Union. The studies are based on internationally accepted guidelines. They establish what scientists agree is an acceptable dose to humans, usually based on a 'no observed adverse effect level' (NOAEL) in animals.

Both long-term and short-term exposures to pesticides are considered during the safety assessment. For long-term exposure to pesticides, the ADI (Acceptable Daily Intake) is used to estimate the amount of a substance that people, including the young, the elderly, the sick and pregnant women, can eat every day of their lives without having an appreciable risk to their health, based on current scientific evidence.

For short-term exposure the ARfD (Acute Reference Dose) is used. This is the amount of a chemical that can be taken in at one meal or on one day without appreciable health risk to anyone consuming it.

Definitions of NOEAL, ADI and ARfD are given in the glossary of terms.