Pesticide Glossary

MedEd Pesticide Defines the Terms Used in Pesticide Safety Data

Acceptable daily intake (ADI)

The acceptable daily intake is the amount a person can take in daily over a lifetime without appreciable health risk.

Acceptable operator exposure level (AOEL)

The acceptable operator exposure level is the exposure at which no adverse effect is expected for applicators.

Acetylcholinesterase

Acetylcholinesterase is the enzyme that breaks down acetylcholine. Organophosphate and carbamate pesticides inhibit it.

Active substance

An active substance is the component of a pesticide product that acts on the pest, weed or disease.

Acute reference dose (ARfD)

The acute reference dose is the amount a person can take in over one meal or day without appreciable risk.

CAS number

A CAS number is a unique numerical identifier that the Chemical Abstracts Service assigns to a chemical substance.

Cholinergic crisis

A cholinergic crisis is a potentially life-threatening emergency from overstimulation of nicotinic and muscarinic receptors.

EU approval status

The EU approval status shows whether the EU has approved a substance as an active ingredient in plant protection products. The EU Pesticides Database uses Approved, Not approved and Pending.

Hazard statement (H-code)

A hazard statement is a standard phrase under EU Regulation 1272/2008 that describes a hazard. H302, for example, means harmful if swallowed.

IARC

IARC is the International Agency for Research on Cancer. It classifies substances by their potential to cause cancer.

LD50

The LD50 is the dose of a substance that kills half of a group of test animals. A lower LD50 means higher acute toxicity.

LOAEL

The LOAEL is the lowest dose in a study at which an adverse effect was observed.

Maximum residue level (MRL)

A maximum residue level is the highest pesticide residue level legally tolerated in or on food or feed.

NOAEL

The NOAEL is the highest dose in a study at which no adverse effect was observed.

Personal protective equipment (PPE)

PPE is protective equipment that handlers wear to keep pesticides off the body.

Pesticide residue

Pesticide residue is the trace amount of a pesticide that remains in or on food after application.

Reference dose (RfD)

A reference dose is an estimate of a daily oral exposure that is unlikely to cause harm over a lifetime.

Restricted-entry interval (REI)

A restricted-entry interval is the time immediately after a pesticide application when entry into the treated area is restricted.

US registration status

The US registration status shows whether EPA currently registers any pesticide product that contains the active ingredient.

Each pesticide page in the database uses these terms. The methodology page explains where the values come from.