| AAPCO | "Association of American Pesticide Control Officials, Inc." |
| Absorption | "Process by which pesticides are taken into tissues, namely plants, by roots or foliage. " |
| Acaricide (miticide) | An agent that destroys mites and ticks. |
| Acetylcholine | A chemical transmitter of nerve and nerve-muscle impulses in animals. |
| Active ingredient | "a. In the case of a pesticide other than a plant regulator, defoliant or desiccant, an ingredient which will prevent, destroy, repel, or mitigate insects, fungi, rodents, weeds, or other pests. b. In the case of a plant regulator, an ingredient which, through physiological action, will accelerate or retard the rate of growth or rate of maturation or otherwise alter the behavior of ornamental or crop plants or their produce. c. In the case of a defoliant, an ingredient which will cause the leaves or foliage to drop from a plant. d. In the case of a desiccant, an ingredient which will artificially accelerate the drying of plant tissue. (ECL § 33-0101 & 6 NYCRR §326.1)" |
| Acute toxicity | The toxicity of a material as determined by its ability to cause injury or death from a single dose or exposure. |
| ADI | Acceptable Daily Intake. A now defunct term for reference dose (RfD). |
| Adjuvant | "An ingredient that improves the properties of a pesticide formulation. Includes wetting agents, spreaders, emulsifiers, dispersing agents, foam suppressants, penetrants, and correctives. " |
| Adsorption | "The chemical and/or physical attraction of a substance to a surface. Refers to gases, dissolved substances, or liquids on the surface of solids or liquids. " |
| AE | Acid Equivalent |
| Aerosol | A suspension of solids or liquids in air. |
| Agricultural animal | "any animal that is raised to produce food, clothing, or other saleable commodity, along with large farm animals, including but not limited to" |
| Agricultural commodity | "any plant or part thereof, or animal, or animal product, produced by a person (including farmers, ranchers, vineyardists, plant propagators, Christmas tree growers, aquaculturists, floriculturists, orchardists, foresters or other comparable persons) primarily for sale, consumption, propagation or other use by man or animals. (ECL §33-0101 & 6 NYCRR §325.1)" |
| a.i. | Active Ingredient |
| Algicide | Chemical used to control algae and aquatic weeds. |
| Alkylating agent | "Highly active compounds that replace hydrogen atoms with alkyl groups, usually in cells undergoing division. " |
| Annual | "A plant that completes its life cycle in one year. That is, a plant that germinates from seed, produces seed, and dies in the same season. " |
| Antagonism | Decreased activity arising from the effect of one chemical or another (opposite of synergism). |
| Antibiotic | A chemical substance produced by a microorganism and that is toxic to other microorganisms. |
| Anticoagulant | A chemical that prevents normal blood clotting. The active ingredient in some rodenticides. |
| Antimicrobial agents | " (1) disinfectants intended to destroy or irreversibly inactivate infectious or other undesirable bacteria, pathogenic fungi, or viruses on surfaces or inanimate objects; (2) sanitizers intended to reduce the number of living bacteria or viable virus particles on inanimate surfaces, in water, or in air; (3) bacteriostats intended to inhibit the growth of bacteria in the presence of moisture; (4) sterilizers intended to destroy viruses and all living bacteria, fungi and their spores, on inanimate surfaces; (5) fungicides and fungistats intended to inhibit the growth of, or destroy, fungi (including yeasts), pathogenic to humans or other animals on inanimate surfaces; and (6) commodity preservatives and protectants intended to inhibit the growth of, or destroy bacteria in or on raw materials (such as adhesives and plastics) used in manufacturing, or manufactured products (such as fuel, textiles, lubricants, and paints), but not those utilized in the pulp and paper process or cooling tow |
| Anti-siphoning device | "the use of a backflow prevention device that uses a reduced pressure zone device or an air gap separation between a water source and the overflow of a receptacle (i.e., spray tank, mixing tank, dipping vat, etc.) containing pesticides, to prevent contaminated water from siphoning back into a water supply. (6 NYCRR §325.1) " |
| Antitranspirant | A chemical applied directly to a plant that reduces the rate of transpiration water loss by the plant. |
| Apiculture | Pertaining to the care and culture of bees. |
| Application of pesticides | the placement for effect of a pesticide at or on the location where pest control is desired. (6 NYCRR §325.1) |
| ARC | Anticipated Residue Contribution |
| Aromatics | Solvents containing benzene or compounds derived from benzene. |
| Atropine (atropine sulfate) | An antidote used to treat organophosphate and carbamate insecticide poisoning. |
| Auxin | A substance found in plants that stimulates cell growth in plant tissues. |
| Avicide | A pesticide agent used to control birds. |