Dictionary of Pesticide Terms 

Acaricide:
A pesticide formulated to kill, harm, repel or mitigate one or more species of spider, mite or tick as the target organism.

Active ingredient:
The component/s of a pesticide formulated to kill, harm, repel or mitigate one or more target organism. Under U.S. law, these must be listed on the pesticide label. See Inert ingredient.

Acute:
Short exposures to high levels of pesticides. Effects on an organism produced by acute exposure may vary widely in severity and reaction time. See Chronic.

Avicide:
A pesticide formulated to kill, harm, repel or mitigate one or more species of bird as the target organism.

Chronic:
Long-term, lingering or repeated exposure to a pesticide. Reaction of an organism to chronic exposure may vary widely but always occurs after a prolonged period. See Acute.

Class:
Pesticides are divided into classes based on their chemical composition e.g., carbamates, organophosphates.

Concentration:
A measure of pesticide levels in an organism or medium. Usually expressed in parts per million (See ppm) or amount of pesticide (usually active ingredient) per weight of medium or per body weight of organism (e.g., mg/kg). See LC50.

Control:
A means of isolating the effects of a specific test hypothesis by setting up a parallel group, subject to the identical conditions as the test group with the exception of the one item whose effects are being tested.

Cumulative:
Additive or increased effect or response of an organism to repeated pesticide exposure (repeat doses may be in different forms).

CWS:
Canadian Wildlife Service. Part of Environment Canada, handles wildlife matters that are the responsibility of the federal government of Canada. These include protection and management of migratory birds, nationally significant habitat and endangered species, as well as work on other wildlife issues.

Degradate:
A breakdown product of a pesticide. Varies widely from one chemical to another in the time this may take (see half-life). May be more harmful than the original chemical e.g., the primary degradate of ethyl parathion, paraoxon, is five times more easily absorbed than parathion and 40 to 50 times more toxic to birds.

Diluent:
An ingredient used to increase the volume and decrease the concentration of a pesticide for purposes of application.

Dose:
The amount of pesticide ingested, injected, inhaled or absorbed by an organism (expressed by mass or more usually by mass of chemical per body weight of organism e.g., mg/kg). See LD50.

EPA:
Environmental Protection Agency. Charged with the regulation of pesticides in the US by a system of registration and review. See FIFRA.

Endangered Species Act:
Enacted in 1973, it affords specific protection to species whose populations are determined to be particularly rare and imperiled. The Department of Interior and Department of Commerce share regulatory jurisdiction of this act, with Interior management undertaken by the USFWS for land, freshwater and some estuarine species, and Commerce management undertaken by the National Marine Fisheries division of the National Oceanographic and Atmospheric Administration for most marine and some estuarine species.

End Point:
A biological process, important to the survival of a species, selected as a criteria in a toxicity test, to determine the effect of a pesticide.

FIFRA:
The Federal Insecticide, Fungicide and Rodenticide Act. The law governing the production, registration and use of pesticides in the U.S.. First passed in 1947, amended in 1972 with control of implementation passed from US department of Agriculture to EPA.

Form/Formulation:
This is the physical state in which a pesticides is manufactured and reflects the way it is applied e.g., granular, powder etc.

Fungicide:
A pesticide formulated specifically to target one or more species of fungi.

Half-life:
The time it takes to reduce the concentration of a pesticide in an organism or medium by half, through transport, degradation or transformation.

Hazard:
Any known, potential adverse effects e.g., cancer, decreased fertility, from the use of a pesticide i.e., decrease in reproductive success in birds is a known hazard of chlorfenapyr use. Any one of these may be used as the end point in a particular toxicity test. See risk.

Herbicide:
A pesticide formulated specifically to target one or more species of plant.

Inert ingredient:
These components of a pesticide's formula need not be listed on the Pesticide Label. They may impact the form of the pesticide and in some cases, its toxicity. Although they are theoretically not toxic to the target organism, many have been shown to be toxic to birds and other wildlife.

Insecticide:
A pesticide formulated specifically to kill, harm, repel or mitigate one or more species of insect.

IPM:
Integrated Pest Management. A management strategy that uses all available tactics (chemical, cultural, biological and mechanical) to manage pests. Most scenarios prioritize non-toxic approaches over toxic and emphasize monitoring pest populations. They therefore have the potential to reduce pesticide inputs to the environment.

Label:
The written, printed or graphic matter, attached to the pesticide container or wrapper. Required by US law to list all active chemical ingredients in a product, its permissible uses and instructions for application. Need not list inert ingredients even though these may be equally toxic.

LC50 (Lethal Concentration):
A measure of a pesticide's acute toxicity by concentration. It is the concentration of a chemical at which 50% of the test group dies. It is a time dependent value (i.e., the length of the test may vary) and may be an observed value or, more frequently, one calculated by interpolation or extrapolation. In birds, currently, groups of young test animals are exposed continuously to graded doses of a chemical in their food for a 5 day period. They are then put on clean feed and observed for at least three more days. The avian LC50 is then expressed as parts per million (ppm) or milligrams of chemical per kilogram of feed. See LD50 and toxicity test.

LD50 (Lethal Dose):
A measure of a pesticide's acute toxicity by dose. It is the quantity of a chemical sufficient to kill 50% of the test group. The chemical is usually administered as a single dose although tests that use repeat dosing are also possible. The chemical is given by injection or ingestion. The LD50 may be an observed value or, more frequently, calculated by interpolation or extrapolation. The LD50 is usually expressed in milligrams of chemical per kilogram of body weight. In birds, currently, adults are given a one-time dose and subsequently observed for at least 14 days. See LC50 and toxicity test.

Lethal poisoning:
Death of the organism directly attributable to exposure to a toxic substance e.g., pesticide. Compare with Sub-lethal poisoning.

LOEC:
Lowest Observable Effect Concentration. The lowest concentration of a chemical at which a statistically significant, adverse effect is measurable on a test organism compared with controls. See NOEC.

MBTA:
Migratory Bird treaty Act. The 1918 law making the 'taking', killing, collection, sale, trafficking or possession of any migratory bird or part thereof (e.g., nest, feathers, eggs) in the U.S. a federal offence. Enforced by the US Fish and Wildlife Service (USFWS), which may issue permits to allow killing, rehabilitation, scientific investigation or other activities under specific circumstances (e.g., seasonal hunting of game species).

Miticide:
A pesticide formulated specifically to kill, harm, repel or mitigate one or more species of mite.

Mode of Action:
The way a pesticide is designed to act on the target organism e.g., cholinesterase inhibitor, anticoagulant etc.

Nematicide:
A pesticide formulated specifically to kill, harm, repel or mitigate one or more species of nematode.

NOEC:
No Observable Effect Concentration. The highest concentration of a chemical at which no statistically significant, adverse effect is measurable on a test organism compared with controls. See LOEC.

Non-target Organism:
An organism not intended to be the target of a pesticide application.

Persistence:
The length of time a pesticide, its residue or degradate remain in the environment after application. See Half-life.

Pesticide:
A group of poisons designed to kill or harm a target organism or group of organisms deemed to be pests. According to FIFRA a pesticide is Pesticide (1) any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest, (2) any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.

Piscicide:
A pesticide formulated to kill, harm, repel or mitigate one or more species of fish as the target organism.

ppm:
Parts per million. An expression of the concentration of a chemical per million units of the medium in which it is being measured (e.g., blood or water). Larger concentrations may be parts per thousand, smaller concentrations, parts per billion.

Resistance:
The decrease in effectiveness of a pesticide over successive generations due to a shift in genetic composition of the target species population. Different from tolerance.

Risk:
The theoretical probability that a pesticide will have some adverse effect on a population. It is a function of the pesticide's toxicity and the organism's exposure to it. Risk is often assessed using mathematical models. See hazard.

Rodenticide:
A pesticide formulated specifically to kill, harm, repel or mitigate one or more species of rodent.

Statistically Significant:
A mathematical measure of determining whether the results from a test prove a difference between the test group and the control.

Sub-Lethal Poisoning:
Exposure to a toxic substance that does not kill the organism but may have other effects such as reduced fertility or decreased body mass. Cumulative effects from multiple exposures may become lethal.

Surfactant:
An inert ingredient which affects surface tension of a pesticide, thus increasing uptake by a target organism.

Target Organism:
The organism/s on which a particular pesticide is designed to act.

Tolerance:
The ability of a species to withstand specified levels of a particular pesticide.

Toxicity:
The capacity of a pesticide to have a specific, adverse effect on an organism. It includes its potency, a measure of the capacity of the pesticide to cause an effect per unit of exposure.

Toxicity Test:
The means by which the toxicity of a chemical to an organism (target or other) is determined. It measures the degree of response to a specific dose from acute (see LD50) or chronic (see LC50) exposure.

Type:
Pesticides are divided into types based on the group of organisms they target ie. Insecticide, Herbicide, Rodenticide, Fungicide.

USFWS:
US Fish and Wildlife Service. Under the Department of the Interior, the USFWS is responsible for protecting wildlife and habitats. Also charged with enforcing the Migratory Bird Treaty Act and Endangered Species Act.