Abiotic degradation:

Process in which a substance is converted to simpler products by physical or chemical mechanisms: examples include hydrolysis and photolysis. [Source: IUPAC]

Absorbed dose (of a substance):

Amount of a substance taken up by an organism or into organs or tissues of interest (Also referred to as: “internal dose”). [Source: IUPAC]

Acceptable Daily Intake (ADI):

Daily intake which, during an entire lifetime, appears to be without appreciable risk to the health of the consumer on the basis of all the known facts at the time of the evaluation of the chemical. It is expressed in milligrams of the chemical per kilogram of body weight. [Source: JMPR]

Acceptable Operator Exposure Level (AOEL):

The maximum amount of active ingredient to which the operator may be exposed without any adverse health effects. []

Active ingredient:

Part of the product that provides the pesticidal action. [Source: International Code of Conduct]

Acute:

Of short duration, in relation to exposure or effect; the effect usually shows a rapid onset. In regulatory toxicology, “acute” refers to studies where dosing is either single or limited to one day although the total study duration may extend to two weeks to permit appearance of toxicity in susceptible organ systems [Source: IUPAC]

Acute exposure:

Contact between an agent and a target occurring over a short time, generally less than a day. (Also referred to as: “short-term exposure” and “single dose”) [Source: IPCS]

Acute Reference Dose (ARfD):

Estimate of the amount of a substance in food and/or drinking-water, normally expressed on a body-weight basis, which can be ingested in a period of 24 hours or less without appreciable health risk to the consumer on the basis of all known facts at the time of the evaluation. [Source: JMPR]

Acute toxicity:

Those adverse effects occurring following oral or dermal administration of a single dose of a substance, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours. [Source: GHS]

Acute toxicity:

Adverse effects of finite duration occurring within a short time (up to 14 days) after administration of a single dose (or exposure to a given concentration) of a test substance or after multiple doses (exposures), usually within 24 hours of a starting point (which may be exposure to the toxicant, or loss of reserve capacity, or developmental change, etc.).

Ability of a substance to cause adverse effects within a short time of dosing or exposure. [Source: IUPAC]

Acute toxicity test:

Study in which organisms are observed during only a short part of the life span and in which there is often only a single exposure to the test agent at the beginning of the study. (Also referred to as: “short-term toxicity test”). [Source: IUPAC]

Adverse effect:

Change in the morphology, physiology, growth, development, reproduction, or life span of an organism, system, or (sub)population that results in an impairment of functional capacity, an impairment of the capacity to compensate for additional stress, or an increase in susceptibility to other influences. [Source: IPCS/OECD]

Application rate:

Mass of pesticide active ingredient applied over a specific area or per unit volume of an environmental component (air, water, soil) [Source: JMPR]

Aspiration:

The entry of a liquid or solid chemical directly through the oral or nasal cavity, or indirectly from vomiting, into the trachea and lower respiratory system. [Source: GHS]

Aspiration toxicity:

Severe acute effects such as chemical pneumonia, varying degrees of pulmonary injury or death following aspiration. [Source: GHS]