The Bugwood Network

Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

  • Absorb – To incorporate or take a substance into another material or a body. Compare… Adsorb
  • Acaricide – A pesticide used to kill mites, spiders, and ticks
  • Acceptable Daily Intake (ADI) – The amount of chemical a person can be exposed to on a daily basis over an extended period of time (usually a lifetime) without suffering deleterious effects
  • Acceptable Exposure Limit (AEL) – The acceptable permissible concentration of a chemical in a work environment (generally as ppm in air) for a defined period of time (generally 8 hours). See also… MEL, OEL, PEL, STEL, TLV, TWA
  • ACGIH – American Conference of Governmental Industrial Hygienists
  • Acid Equivalent (a.e. or ae) – The portion of a compound or formulated product that theoretically could be converted back to its corresponding acid
  • Acre (a or ac) – A unit of area equal to 43,560 square feet. The equivalent of one acre of water or soil which is 1 foot deep; thus, 1 ac x 1 ft, 0.5 ac x 2 ft, or other variant. (43, 560 square feet x 1 ft = 43,560 cubic feet of either water or soil). See also… Surface acre
  • Activation – The process by which a surface applied herbicide is moved into the soil where it can be absorbed. This is normally accomplished by rainfall, irrigation or tillage
  • Active Ingredient – The chemical(s) in a formulated product that is (are) principally responsible for the pesticide’s effect; listed as active ingredient(s) on the label
  • Acute Exposure – One or multiple doses of short duration spanning up to but no more than 24 hours
  • Acute Toxicity – Any poisonous effect produced within a short period of time, up to 96 hours, following an exposure. See also… Chronic toxicity, Subchronic toxicity
  • Adaptation – The process whereby repeated exposures to small amounts of a chemical cause a plant or animal population to become tolerant to the chemical by permitting only tolerant individuals to propagate the population
  • Additive Effect – A situation in which the combined effect of two or more chemicals is equal to the simple sum of the effect of each chemical alone. This is the most commonly expressed effect of combined chemicals. See also…Antagonism, Synergism
  • Adjuvants – Compounds which, when added to pesticides, act as wetting or spreading agents, stickers, penetrants, emulsifiers, drift control agents, etc. and make the pesticide easier to handle, mix, or apply, or increase its effectiveness
  • Adsorb – To hold or bind a substance onto the surface of another material or a body. Compare… Absorb
  • Adverse Effect – A biochemical change, functional impairment, or pathologic lesion that affects performance of the whole organism, or reduces an organism’s ability to respond to an additional environmental challenge
  • Aerial Application – Application of a pesticide by using an airplane or helicopter as the vehicle from which the material is dispensed in a broadcast pattern over the landscape; most commonly used for insecticidal applications but some herbicidal work is also done in this manner
  • Aerobes – Organisms which require free oxygen to live
  • Aerosol (A) – A suspension of liquid or solid particles in air; a pesticide formulation designed to be suspended in the air by the action of a propellant gas causing fine droplets to be produced through a nozzle
  • Agitation – Stirring or mixing in a pesticide tank to retain an even distribution of an emulsified or suspended pesticide
  • Algae – Primitive, chiefly aquatic, unicellular or multicellular plants that lack true stems, roots or leaves, but usually contain chlorophyll
  • Algicide – Any pesticide used to mitigate or control algae
  • Allelopathy – The direct or indirect effect of one plant on another through the production of chemicals that affect the growth of the affected plant
  • Amine (Amine Salt) – A type of chemical formulation (derived from ammonia) which is soluble in water
  • Anaerobe – Organisms which do not require free oxygen to live
  • Anecdotal Data – Data based on the description of individual cases rather than on controlled studies
  • Annual Plant – A plant (species) living and growing for only one year or season. See also… Biennial, Perennial
  • Antagonism – An effect produced by two or more chemicals applied together which causes less effect in combination than would be predicted based on the effects caused when they are used separately. See also… Additive effect, Synergism
  • Anticoagulant – A chemical designed to prevent the clotting of blood in target animals
  • Antidote – Any substance used to counteract a poison
  • Approximate Lethal Concentration (ALC) – An estimate of the concentration of a pesticide in air or water which is capable of killing a test animal. See also… MLC
  • Approximate Lethal Dose (ALD) – An estimate of the dose of a pesticide which is necessary to kill a test animal. See also… MLD
  • Aqueous – Indicating the presence of water; a solution of a chemical in water
  • Aquifer – An underground zone of earth or rock saturated with water whose upper limit is the water table
  • ATSDR – Agency for Toxic Substances and Disease Registry, US Department of Health
  • Attractant – A pesticide or additive used to lure pests. See also… Bait
  • Average Daily Dose (ADD) – The dose rate (averaged over a pathway-specific period of exposure) expressed as a daily dose on a per-unit-body-weight basis. The ADD is usually expressed in terms of mg/kg-day or other mass-time units
  • Average Daily Intake (ADI) – The dose rate (averaged over a pathway-specific period of exposure) expressed as a daily intake on a per-unit-body-weight basis. The ADI is usually expressed in terms of mg/kg-day or other mass-time units
  • Avicide – A pesticide used to control birds; more commonly a repellant than a killer

B

  • Bait – A pesticide product formulated with a pest attracting component. See also...Attractant
  • Band Treatment – A treatment applied to a narrow linear strip of land or along a crop row
  • Basal Treatment – A pesticide application made so as to encircle the stem of a plant just above the ground line such that foliage contact is minimal. A term used mostly to describe treatment of woody plants with herbicide
  • Benzoic Acids – A family of herbicides closely related to the phenoxy herbicides but having a carboxylic acid group (COOR) attached to the benzene ring replacing the methyl group attached via an oxygen atom. Benzoic acids act as plant growth inhibitors by interfering with cell division processes; they include banvel and chloramben
  • Biennial Plant – A plant (species) that completes its life cycle, from seed germination to seed production, in two years. Also means to occur every two years. See also...Annual, Perennial
  • Billion International Units (BIU) – Expression of bacterial potency
  • Bioaccumulation (Bioconcentration) – The process by which a plant or animal selectively takes in and stores a persistent substance resulting in the presence of a higher concentration of the substance being present in the organism than in its environment. Compare…Biomagnification
  • Bioassay – A scientific test to determine the potency (or concentration) of a substance that causes a biological change in experimental animals
  • Bioavailability – The degree to which a substance becomes available to the target tissue after administration or exposure
  • Biochemical – A chemical that is produced by a living organism
  • Biocide – A nonspecific word (generally found in sensational journalism) that indicates the ability of a pesticide to kill all life it encounters
  • Bioconcentration Factor (BCF) – A mathematical ratio or percentage which relates the concentration of a pesticide in the environment (air, food or water) to the concentration in an animals body. A BCF of greater than 1 indicates that the animal is retaining the pesticide at a concentration greater than that in its habitat
  • Biocontrol Agent – An organism used to control another organism through antagonistic growth process or via the production of an allelopathic biochemical
  • Biological Control (Biocontrol) – The process of applying or favoring one biological organism in an attempt to control another
  • Biomagnification – The increase in concentration of a foreign chemical as you move higher in the food chain. Compare…Bioaccumulation
  • Biorational Pesticide – Biological pesticides including bacteria, viruses, fungi and protozoa and chemical analogues of naturally occurring biochemicals (pheromones, insect growth regulators, etc.) which act to control pests
  • Broadcast Treatment – A treatment which is applied uniformly over an entire area, by ground or aerial means
  • Broadleaf Weed – A nonwoody dicotyledenous plant with wide bladed leaves designated as a pest species in gardens, farms, or forests
  • Buffer Strip – A strip of vegetation left unmanaged (or untreated) to reduce or prevent the impact of a treatment from affecting adjacent untreated resources

C

  • CAA – Clean Air Act of 1955 as amended
  • Calibration – The process of adjusting the amount of material per unit area or per pull of a triggering device to achieve a standard rate of application of pesticide in an area
  • Cancel (FIFRA regulatory action) – The official revocation of a specific use or all uses of a pesticide by the EPA; remaining stocks may be used as originally labeled by the formulator. See also…Suspend
  • Cancer – A disease of heritible, somatic mutations affecting cell growth and differentiation, characterized by an abnormal, uncontrolled growth of cells
  • Carbamate – A family of organic esters (primarily insecticides or herbicides) which are derived from carbamic acid and share the following common features: an organic base molecule with a nitrogen atom connecting an alcohol group (COOH) to the base. Carbamates interfere with an insects respiration
  • Carcinogen – An agent capable of inducing or producing cancer
  • Carcinogenesis – The origin or production of a (benign or malignant) tumor
  • Carcinoma – A malignant tumor
  • Carrier – A gas, liquid, or solid substance used to dilute, propel, or suspend a pesticide during its application
  • CAS – Chemical Abstract Service
  • CAS# – A unique number assigned to a chemical by the Chemical Abstracting Service to be used as a reference number to key data retrieval
  • CAS Registry – Master file of Chemical Abstracting Service numbers
  • cc – Cubic centimeter(s)
  • CERCLA – Comprehensive Environmental Response, Compensation, and Liability Act of 1980 as amended
  • Certified Applicator (FIFRA meaning) – Any individual who is certified as authorized to use or supervise the use of any pesticide which is classified for restricted-use. See also…Commercial applicator, Private applicator
  • CFR – Code of Federal Regulations
  • Chemical Control – The process of using a chemical pesticide to affect or determine the location or growth of pest organisms as defined by the applicator
  • Chemical Name – The systematic name of a chemical compound according to the rules of nomenclature of the International Union of Pure and Applied Chemistry as adapted for indexing in Chemical Abstracts. See also…Common name, Trade name, Return to Name, Product name
  • CHEMTREC – Chemical Transportation Emergency Center 1-800-424-9300
  • Chemolytic – Capable of causing the chemical breakdown of another a substance
  • Chlorinated Hydrocarbon – An organic (carbon containing) insecticide, having either a branched chain or ring structure, which contains one or more chlorine atoms. See also…Organochlorine
  • Chlorosis – Apparent loss of green coloration from leaves, generally the result of failure to produce chlorophyll
  • Chinese Hamster Ovary (CHO) – One of the many mutagenicity tests employing Chinese hamster ovary cells as the test medium
  • Chronic Effect – An effect which occurs as a result of repeated or long term (chronic) exposures
  • Chronic Exposure – Multiple exposures occurring over an extended period of time, or a significant fraction of the animal’s or the individual’s lifetime; generally taken to mean a time span greater than half of the individual’s expected life-span
  • Chronic Toxicity – The capacity of a substance to cause adverse human health effects as a result of repeated exposure to a chemical for greater than half the life expectancy of the test asubjects. See also…Acute toxicity, Subchronic toxicity
  • CIIT – Chemical Industry Institute of Toxicology
  • CNS – Central nervous system
  • Commercial Applicator (FIFRA meaning) – An applicator (whether or not he or she is a private applicator with respect to some uses) who uses or supervises the use of any pesticide which is classified for restricted-use for any purpose or on any property not owned or rented by him or her or his/her employer or which application is for compensation on the property of another person. See also… Certified applicator, Private applicator
  • Common Name – A generic name for a chemical compound (see WSSA list of herbicide nomenclature). See also…Chemical name, Trade name, Return to Name, Product name
  • Compatibility – The characteristic of substances which allow their mixing in a common carrier as a formulated product or a tank mix without undesirably altering the characteristics and effects of the individual components
  • Concentration (of a pesticide) – The amount of active ingredient or its acid equivalent in a quantity of diluent, expressed as ratio of the ai or ae per unit of volume of the product, for example lb/gal, ml/L, etc
  • Confidential Business Information (CBI) – Data submitted to the EPA to support the registration of a product which is protected from general public disclosure under Section 10 of FIFRA. Generally speaking protected information is material classed by the manufacturer as a trade secret or is commercial or financial information rather than relating to organism or ecological toxicology
  • Conifer – A taxonomic order of trees (Gymnospermae (Coniferae)), comprised of a wide range of (mostly) evergreens that bear cones and have needle-shaped or scale-like leaves. Their timber is generally commercially sold as ‘softwood’
  • Contact Herbicide – A herbicide that causes injury to only the plant tissue to which it is applied, or one which is not appreciably translocated within a plant. See also… Systemic pesticide, Translocated herbicide
  • Contact Insecticide – An insecticide which causes injury or death of an insect through the touch rather than through inhalation or ingestion. See also…Systemic pesticide
  • Contaminate – To make impure or pollute; the addition of unwanted material
  • Corrosive – A substance which usually contains a strong acid or base which may burn the skin or eyes, or may damage certain types of spray tanks and other equipment
  • Corrosive Effect – An irreversible destructive effect of an acid or a base on either organic or inorganic materials. In biological systems corrosive effects are distinguished from irritant effects. See also… Irritant effect
  • Coverage – The spread or distribution of a pesticide over a surface or area
  • Crop Advisor (WPS definition) – Any person who is assessing pest numbers or damage, pesticide distribution, or the status, condition, or requirements of agricultural plants. The term does NOT include any person who is performing hand labor tasks, such as weeding, planting, cultivating, or harvesting. See also.. Handler, Worker
  • Cut-stump Treatment – Application of a pesticide to a freshly created wound which has exposed the vascular tissue of a tree which allows rapid uptake of the applied chemical. Included here are cut stump treatments, injection treatments and hack-n-squirt treatments
  • CWA – Clean Water Act of 1948 as amended

D

  • DAT – Days after treatment
  • Deciduous – Pertaining to any plant organ or group of organs that is shed naturally; plants that are leafless for some time during the year
  • Defoliant – A pesticide whose primary purpose is to remove unwanted foliage without necessarily killing the entire plant
  • deg – Degree – a measure of temperature. Normally identified as degrees Farenheit, Celsius, or Kelvin
  • Degrade(of chemicals) – The breaking down of a chemical to component parts by chemical or biological processes. Return to…Environmental or Metabolic degrade
  • Deoxyribonucleic Acid (DNA) – Chemical building blocks of chromosomes DNA is the basic molecular determinant of heredity
  • Dermal Exposure – Exposure of an organisms skin to a pesticide or other substance
  • Desiccant – Any substance or mixture of substances used to accelerate the drying of plant or animal tissue
  • Dicotyledon (dicot) – A plant, member of the plant family Dicotyledoneae; usually characterized by having the following –two seed leaves (cotyledons), leaves with net veination, and root systems with a tap root
  • Diluent – Any gas, liquid, or solid material used to reduce the concentration of an active ingredient in a formulation
  • Dip – The complete or partial immersion of a plant, animal or other object in a dilute pesticidal mixture or solution. Or, a slurry which incorporates a pesticide
  • Directed Foliar Application – A selective pesticide application, generally using a portable backpack sprayer, in which only the leaves of specifically targeted plants are treated
  • Dislodgeable Residue – The remainder of a chemical or biological agent on foliage resulting from aerial or ground spray application, which can be readily removed from the foliage by washing, rubbing, or having some other form of direct contact with the treated vegetation
  • Dispersible Granule – A dry granular formulation which will separate or disperse to form a suspension when added to water
  • Dormancy – A resting or inactive state
  • Dormant Spray – A pesticide application made during the winter or very early spring before the target plants have started growing
  • Dose – The amount of a chemical, physical, or biological agent which crosses the exchange boundary (skin, stomach, lungs, etc.) of an organism; the amount of a foreign agent internalized by an organism. Compare…Exposure
  • Dose-Response Assessment – A determination of the relationship between the size of an administered, applied or internal foreign chemical and a specific biological reaction to the chemical
  • DOT or D.O.T. – US Department of Transportation
  • Dow IHG – Dow Industrial Hygiene Guide
  • Drift – Aerial off-target movement of a pesticide during or immediately after application. Drift may occur as movement of actual droplets or particles during application, or as a result of the evaporation of a volatile pesticide during or subsequent to application. Return to…Vapor drift
  • Dry Flowable (DF) – A dry, relatively free-flowing powder containing the pesticidal a.i. This powder is generally ready to be dispersed in water for spray application although some formulations require a wetting agent to insure proper dispersal

E

  • E – Exponent when used in numeric data tables (for example: 10E5 = 10 See also… Emulsion
  • Economic Threshold – The point in an infestation where the application of control measures would return more money than the cost of application of the measures
  • Ecosystem – The living and non-living entities in an area and their interactions; scale of the "area" depends on who is defining the ecosystem, but at the system level it is usually considered to be a fairly large unit such as a river basin, a forest, or a swamp. Smaller units within these ecosystems are usually designated by other terms. See also… Habitat, Niche
  • Efficacy – The ability to produce the desired effect; effectiveness
  • Emergence – The event in seedling establishment when a shoot becomes visible by pushing through the soil surface
  • Emersed Plant (Emergent) – A rooted or anchored aquatic plant adapted to grow with most of its leaf and stem tissue above the water’s surface and not lowering or rising with the water level. See also…Floaters, Immersed plants, Submergents
  • Empirical – Relationship described, but not necessarily fully understood, based on observation or experimentation rather than hypothesis or theory
  • Emulsifier – A substance which promotes the suspension of one liquid in another; a surface active substance used to stabilize suspensions of one liquid in another, for example, oil in water
  • Emulsifiable Concentrate – A pesticide mixture dissolved in a liquid solvent in which an emulsifier is included so that the pesticide can be diluted with oil or water for application
  • Emulsion (E) – Small droplets of an oil or ester suspended (not dissolved) in water
  • Encapsulated Formulation – Pesticide enclosed in capsules (beads) of material to control the rate of release of the active ingredient and thereby extend the period of activity
  • Endpoint – An observable or measurable biological event or chemical concentration (for example the concentration of a metabolite in a target tissue) used as an index of an effect of a chemical exposure
  • Enzyme – A biological catalyst; a protein produced by the organism itself, that enables the splitting or fusion of other chemicals
  • EPA – U.S. Environmental Protection Agency
  • EPA Establishment Number (EPA Est. No.) – A unique number assigned by the EPA to each pesticide production plant which identifies the origin of chemicals in the marketplace. This number must be displayed on the label of the product
  • EPA Registration Number (EPA Reg. No.)– A unique number assigned by the EPA to each pesticide product as it is registered. This number must be displayed on the label of the product. Return to…Registration, Registration number
  • EPCRA – Emergency Planning and Community Right-to-Know Act of 1986 as amended
  • Epidemiology – The study of disease patterns in a human population
  • Epinasty – The state in which greater growth on one side of a plant organ causes it to curl
  • E.S.A. – The Endangered Species Act of 1973 as amended. Also… Entomological Society of America. (Meaning derived from context)
  • Ester – A type of chemical formulation which is soluble in oil; a chemical formed by the reaction of an acid and an alcohol, generally accompanied by the elimination of water
  • Exposure – Contact made between a chemical, physical, or biological agent and the outer boundary of an organism; the amount of an agent available at the exchange boundary (stomach, skin, lungs, etc.) of the organism. Compare…Dose
  • Exposure Assessment – The identification and evaluation of the human population exposed to a toxic agent, describing its composition and size, as well as the type, magnitude, frequency, route, and duration of exposure
  • Extender – A chemical which increases the persistence of a herbicide in soil
  • Extrapolation – The use of mathematical models to make estimates outside of the observable range

F

  • Federal Register (FR) – Daily publication of the Government Printing Office in which public regulations and legal notices issued by the Federal Government (all Agencies and Branches) are made available. The EPA uses this publication to release new regulations and planning documents relevant to pesticide use and management
  • FIFRA – The Federal Insecticide, Fungicide, and Rodenticide Act (of 1947) as amended; the principle federal law regulating pesticide manufacture, sale and use in the U.S
  • fl – Fluid
  • Floater or Floating Plant – A free-floating or anchored aquatic plant adapted to grow with most of its vegetative tissue at or above the water’s surface; floaters lower or rise with the water level. See also… Emergents, Immersed, Submergent
  • Foliar Application – Application of liquid pesticide to the leaves of plants, often to the point of runoff
  • Forb – Any herbaceous plant other than grass or grasslike plants (sedges and rushes)
  • Formulated Product (Formulation) – A mixture of active and inert ingredients which is a merchantable pesticide. Some formulations are ready to use; others must be diluted. See also…Ready-to-use, Technical grade
  • Frank Effect Level (FEL) – The level of exposure or dose which produces irreversible adverse effects as a statistically or biologically significant increase in frequency or severity between those exposed and those not exposed
  • Frill Treatment – A ring of nearly continuous cuts around a tree at a convenient height which sever the continuity of the phloem in the bark and exposes the cambium. These cuts may be treated with herbicide. See also…Hack-and-squirt, Injection, Injector
  • FS – U.S.D.A. Forest Service
  • ft – Foot or feet
  • Fumigant (F) – A pesticide which functions while in gaseous form; may be applied as a liquid, gas or solid (often formulated as a pellet which volatilizes to a gas)
  • Fungicide – A pesticide used to control fungi
  • Fungistatic – Inhibiting the germination of fungal spores
  • FWS – U.S. Fish and Wildlife Service

G

  • g – Gram – generally gm
  • ga – Gallon(s)
  • Gavage – The placement of a test substance directly into the stomach of a test animal using a gastric tube. Compare to…Ingest
  • General-use Pesticide – A pesticide that will not cause unreasonable adverse effects on the environment when used as directed, and that may be purchased and used by the general public. See also…Restricted-use pesticide
  • Genotoxic – Causing direct damage to genetic material; generally associated with carcinogenicity
  • Germination – The process of initiating growth in seeds
  • gm – Gram
  • gpa – Gallons per acre (generally referring to the liquid output of a sprayer)
  • gpm – Gallons per minute (generally referring to the liquid output of a sprayer)
  • Granule or Granular Formulation (G) – A dry formulation of pesticide and other components (often clay) in discrete particles generally less than 10 cubic millimeters in size which is designed to be applied without a liquid carrier
  • Grass – Any plant characterized by having narrow leaves, a hollow jointed stem and spikes or clusters of membranous flowers borne in smaller spikelets; may be annual or perennial. Grasses are classified in the family Gramineae
  • Ground Application – Any application of pesticide performed using ground-based personnel and tools; includes mechanical equipment operated on the ground or equipment carried and used by walking persons
  • Growth Regulator – Organic substance which in minute amounts controls or modifies plant or animal growth processes
  • Guidelines (regulatory) – Official, peer-reviewed documentation stating current U.S. EPA methodology to be used in assessing the risk of harm from environmental pollutants to populations

H

  • ha – Hectare
  • Habitat – The area or type of environment (physical and biological) which make up the immediate place in which an organism lives or occurs. See also…Ecosystem, Niche
  • Hack-and -Squirt – A cut-surface application in which a hatchet or similar cutting tool is used to make cuts through the bark to expose the cambium at intervals around the stem of a tree, and a squirt bottle is used to apply a metered amount of herbicide into each fresh cut. See also…Frill treatment, Injection, Injector. Return to…Notch-and-cup treatment
  • Half-life – The time required for half the amount of a substance (such as a herbicide) in or introduced into a system (living or ecological) to be eliminated whether by excretion, metabolic degradation, off-site transport, or other natural process
  • Handler (WPS definition) – A pesticide handler is anyone who: (1) is employed (including self-employed) for any type of compensation by an agricultural establishment or a commercial pesticide handling establishment that uses pesticides in the production of agricultural plants on a farm, forest, nursery, or greenhouse, and (2) is doing any of 9 specific tasks amend in the standard. See also…Crop Advisor, Worker
  • Hardwood – Broadleaved flowering trees. In the Southeast hardwoods are generally deciduous
  • Hazard – A potential source of harm; the risk of danger or harm
  • Hazard Analysis – The process of determining whether exposure to an agent can cause an increase in the incidence of a particular adverse health effect and whether the effect is likely to occur in humans
  • Hazard Identification – The process of identifying the array of potential effects that an agent may induce in an exposed population
  • Hazard Quotient (HQ) – The ratio of the estimated level of exposure to the RfD or some other index of acceptable exposure. See also…RfD
  • HAZMAT – Hazardous material(s)
  • Herbaceous – A plant (annual, biennial, or perennial) that does not develop persistent woody tissue above the ground, and whose aerial portion dies back to ground level at the end of a single growing season. Included here are grasses, grass-like plants (sedges, rushes), and forbs
  • Hematological – Pertaining to the blood
  • Herbicide – A chemical or biological organism or byproduct used to kill or severely interrupt the growth processes of unwanted plants
  • Highest Dose Tested (HDT) – The highest dose tested in an experimental procedure. Generally used with expressions of the NOEL or NOAEL. See also…NOEL, NOAEL
  • HMIS – Hazardous Materials Information System
  • Host – Any organism affected by a pathogen in a disease
  • hr – Hour
  • HSDB – Hazardous Substances Data Base
  • Hydrolysis – Chemical decomposition or alteration of a substance by water

I

  • IARC – International Agency for Research on Cancer
  • IMO – International Maritime Organization
  • in – Inch
  • In vitro – Isolated from a living organism and artificially maintained, as in a test tube. Compare with…In vivo
  • In vivo – Occurring in a living organism. Compare with…In vitro
  • Incorporate – To mix or blend a herbicide into the soil
  • Individual Risk – The probability that an individual will experience an adverse effect
  • Inert Ingredient – All ingredients in a formulated pesticide product which are not classified as active ingredients. Note: Inert as used here is a defined usage of the word; many chemicals which are ‘inert’ under this definition are biologically active
  • Ingest – To eat, swallow, drink or in some active way take something into the digestive system. See also…Gavage
  • Infection – The process of establishing a disease in a host organism or a diseased area in a body
  • Inhalation Exposure – Exposure of an organism to a pesticide or other substance via the nose, nasal passage, or lungs
  • Injection – The application of a pesticide into or through the bark of a tree by a tool designed for that purpose. See also…Frill treatment, Hack-and-squirt, Injector
  • Injector 1/3 – A device used to inject herbicide into the cambium of a tree. –Contd. See also…Frill treatment, Hack-and Squirt, Injection
  • Injector 2/3 – Generally, an injector bar is used in forestry to inject herbicide into trees. It is constructed from a long metal tube which serves both as a herbicide tank and as a handle, with filler cap at one end, and a sharpened bit and a valve at the other. A manually operated trigger (rigid lever or trip wire) releases the herbicide through the valve into cuts made by the bit. -- Contd
  • Injector3/3 – A second form of injector is used for the delivery of insecticide or fungicide directly to the vascular system. In this process small hollow tubes are placed in holes drilled around the circumference of a tree (often at the butt flare at ground line) and then are connected by (plastic) tubing to a pesticide reservoir. Delivery of the pesticide is either by gravity feed or by gas pressurized discharge
  • Inorganic Chemical Compound – Any chemical compound which does not contain carbon
  • Insect – A small, invertebrate animal which has three body regions and six, jointed legs; insects may have two or four, or no wings
  • Insecticide – A chemical or a biological organism or byproduct used to kill or mitigate the action s of insects
  • Instar – The interval of time between molts in the development of an immature insect. See…Larva, Metamorphosis
  • Integrated Pest Management (IPM) 1/2 – A process in which all aspects of a pest-host system are studied and weighed to provide the resource manager with information for decisionmaking. The information provided includes the potential impact of the unregulated pest population on various resource values, alternative regulatory tactics and strategies, and benefit-cost estimates for these alternative strategies. – Contd
  • Integrated Pest Management (IPM) 2/2 – Regulatory strategies are based on sound silvicultural practices and the ecology of the pest-host system. Strategies most commonly consist of a combination of tactics such as stand improvement plus selected use of pesticides. The overriding principle in the choice of strategy is that it be ecologically acceptable
  • Inversion – A weather condition resulting when the temperature rises with elevation from the earth’s surface. During an inversion the normal pattern of warm air rising does not occur or occurs very slowly and the cooler air above traps suspended materials (particulates, aerosols, etc.) in the low level warm air
  • Invert Emulsion – Small droplets of water suspended in oil. In many cases, formation of an invert emulsion is undesirable in a pesticide mixture; most commonly it results in a sludge (the approximate consistency of mayonnaise) which clogs the hoses and valves of application equipment
  • IRIS – The US EPA’s Integrated Risk Information System; deals with pesticide risks
  • Irritant (effect) – A reversible effect from a foreign chemical or substance as opposed to a corrosive effect. See also…Corrosive effect
  • IUPAC – The International Union of Pure and Applied Chemistry; the group which assigns standardized chemical names
  • Immersed Plant – Plants which grow completely submerged in water, but are not rooted to the bottom. See also…Emergents, Floaters, Submergents
  • Interim Reregistration Eligibility Document (IRED) – A document prepared by EPA for a pesticide undergoing reregistration which requires a RED and also has a cumulative risk assessment under FQPA. The IRED remains in place in lieu of and until a RED is finalized. See also…RED, TRED

J

  • None at Present

K

  • kg – Kilogram
  • km – Kilometer

L

  • L or l – Liter
  • Label – The written, printed, or graphic matter on, or attached to, a pesticide container which includes basic chemical information, safety precautions, and legal application practices for the pesticide. The minimum information content of labels is legally controlled by the EPA under guidance in FIFRA and the WPS. Return to…Registration
  • Labeling – The pesticide label, plus any supplemental instructions or guidance supplied by the pesticide's manufacturer, formulator, or distributor. Labeling includes the label, any supplemental labels, the MSDS, technical data sheets, other product summaries, use guidance pamphlets, etc. which are manufacturer produced
  • Larva – An immature insect life stage. See also…Instar, Metamorphosis
  • Larvicide – Insecticide designed to kill insects while in the immature (larval) stages of growth. Most commonly used to describe mosquito control insecticides, the term also includes caterpillar and other larvae controlling pesticides
  • Latency Period – The time between first exposure to an agent and manifestation of a health effect
  • Lateral Movement – Movement of a herbicide through soil, generally in a horizontal plane, from the original site of application
  • lb – Pound
  • Leaching – The movement of a substance downward or out of the soil as the result of water movement
  • LFL – Lower flammability limit
  • liq – Liquid
  • Lowest Dose Tested (LDT) – The lowest dose administered in an experiment. Data reported as LDT indicate that effects seen at this level may have occurred at a lower dose level but it is impossible to state what that is
  • Lowest Observed Adverse Effect Level (LOAEL) – The lowest exposure level at which there are statistically or biologically significant increases in frequency or severity of adverse effects between exposed populations and non-exposed (control) populations
  • Lowest Observed Effect Level (LEL or LOEL) – The lowest exposure level at which there are statistically or biologically significant increases in frequency or severity of observable (not necessarily adverse) effects between exposed populations and non-exposed (control) populations
  • Lysis– To break down, dissolve or decompose
  • Lytic – Capable of breaking something down

M

  • m – Meter
  • m3 or m3 – Cubic meter; a volume equivalent to a container 1 meter x 1 meter x 1 meter
  • Malignant – Cancerous
  • Mammals – Warm-blooded animals which nourish their young with milk
  • Manual Control – The use of hand-held tools to control a pest population; control may be achieved by chemical application via a backpack sprayer, injector or other pesticide application tool, or by using hand-held cutting, ripping, or grubbing tools
  • Margin of Safety (MOS) – The ratio between the animal NOEL and the estimated human dose received. A larger MOS indicates a smaller dose compared with the NOEL and thus a smaller human risk. . In order to satisfy the criterion suggested by the EPA and adopted in Region 8, the quotient of this formula must be greater than or equal to 100.0 to pose an acceptable level of risk
  • Material Safety Data Sheet (MSDS) – A legal document listing the contents and characteristics of a pesticide or other chemical formulation, including: hazardous ingredients; physical data; fire and explosion hazard data; health hazard data; reactivity data; spill or leak response procedures; special protection information; and other special precautions
  • Mechanical Control – The use of tools mounted on mechanical equipment such as a tractor of skidder, to control a pest population; control may be achieved by chemical application (via a boom sprayers, mist blowers, or other mechanical pesticide application tool) or it may be accomplished by the use of machine mounted cutting, ripping, crushing or macerating tools
  • Median Lethal Concentration (LC50, LC50 or MLC) – One measure of toxicity - the concentration of a substance in an environment (generally air or water) which produces death in 50% of a population of test animals exposed to it for a specified period of time. Expressed as milligrams of the substance per liter (air or water), or as parts per million or parts per billion. Return to…LC50, ALC
  • Median Lethal Dose (LD50, LD50 or MLD) – A measure of toxicity - the amount (dose) of a substance which produces death in 50% of a population of test animals to which it is administered by any of a variety of methods. Expressed as milligrams of the substance per kilogram of animal body weight. Return to…LD50, ALD
  • Meristem – The growing point or area of rapidly dividing cells at the tip of a stem, root, branch, or leaf
  • Metabolite – A chemical derived from plant or animal metabolic breakdown or biochemical transformation of another chemical
  • Metamorphosis – A change in shape, form or structure, and size of an insect from the egg to adult stages; may be gradual or complete Immature insects regardless of type of metamorphosis may go through as many as five instars. See also…Metamorphosis – gradual, Metamorphosis – complete, Instar
  • Metamorphosis - Complete – A change in shape, form or structure, and size of an insect from the egg to adult stages in which immature (egg, larva, and pupa) and adult stages have significantly different appearance. See also…Metamorphosis, Metamorphosis – gradual, Larva, Pupa
  • Metamorphosis - Gradual – A sequential or staged change in size of an insect from the egg to adult stages where the adult is basically a larger version of the immature (egg and nymph) stages. See also…Metamorphosis, Metamorphosis-complete
  • mg – Milligram
  • mg/kg – Milligram per kilogram
  • mg/L – Milligram per liter
  • mi– Mile
  • Microbial Breakdown – The breakdown of a complex substance into smaller component chemicals by microbes
  • Microfoil Nozzle – A nozzle, generally used in aerial applications, designed to produce a spray of relatively large, uniform droplets, with the objective of minimizing drift
  • Microorganism (Microbe) – A generic term for all organisms of microscopic size including bacteria, viruses, fungi and protozoa
  • Miscible Liquid – Liquids capable of being mixed in any proportion and remaining mixed under normal temperatures and pressures
  • Mitigation Measure – Any action taken to lessen adverse impacts or enhance beneficial effects; any action designed to change an effect
  • ml – Milliliter
  • mm – Millimeter
  • Model – A mathematical formula or set of formulae with data inputs (parameters) that can be adjusted so that the mathematical expression(s) closely describe a set of empirical data
  • Monocotyledon (monocot) – A member of the Monocotyledoneae; usually characterized by having the following – one seed leaf (cotyledon), leaves with parallel veination, and generally diffuse (fibrous) root systems which arise adventitiously
  • mph – Miles per hour
  • MSHA – Mine Safety and Health Administration
  • Multiple Chemical Sensitivity (MCS) – A syndrome in which individuals are postulated to be extremely sensitive to and negatively affected by concurrent exposure to extremely low levels of many chemicals. The literature is unclear as to whether this syndrome is the result of additive or synergistic effects, or both or even if it is a single syndrome or a family of similar syndromes
  • Mutagenn – A substance capable of permanently altering the structure of DNA
  • Mutagenesis – The process of causing change to DNA
  • Mutagenicity – The capacity of a substance to cause changes in genetic material (primarily DNA)
  • Mutant – An organism which differs from its parents as a result of an alteration in its genetic material
  • Mutation – An alteration or change in genetic material (primarily the DNA)
  • Mycoplasma – A microorganism intermediate in size between viruses and bacteria, which possesses many virus-like properties
  • Maximum Exposure Limit (MEL) – The maximum permitted concentration of a chemical to which a worker may be exposed over an extended period of time (typically quoted as ppm for 8 hours). In many countries MELs are legally enforceable. See also… AEL, OEL, PEL, STEL, TLV, TWA

N

  • n.a. or na – Not available or not applicable; depending on context
  • Name (of a pesticide product) – See… -Chemical name, Common name, Trade name
  • NAS – National Academy of Sciences
  • NCI – National Cancer Institute
  • Necrosis – Localized death of tissue usually characterized by browning and desiccation
  • Nematicide – A chemical, or a biological organism or byproduct (but most often a fumigant chemical) used to kill nematodes
  • Nematode – Microscopic roundworm
  • Neoprene – A synthetic rubber often used to make chemically resistant gloves, boots and spray hoses
  • NEPA – National Environmental Policy Act of 1969 as amended
  • NFMA – National Forest Management Act of 1976 as Amended
  • NFPA – National Fire Protection Association
  • Neurotoxicity – The ability to damage nerve tissue
  • Niche – The set of functional relationships of an organism or population to the environment it occupies; the area within a habitat occupied by an organism. See also…Ecosystem, Habitat
  • NIH – National Institute of Health
  • NIOSH – National Institute of Occupational Safety and Health
  • No Observed Adverse Effect Level (NOAEL) – The highest exposure level at which there are no statistically or biologically significant increases in frequency or severity of adverse effects between exposed populations and non-exposed (control) populations. See also…Highest dose tested
  • No Observed Effect Level (NOEL) – The highest exposure level at which there are no statistically or biologically significant increases in frequency or severity of any observable (not necessarily adverse) effects between exposed populations and non-exposed (control) populations. See also…Highest dose tested
  • Non-crop Area – Land areas on which no vegetation is being grown for the purpose of producing an agricultural or forestry crop. These areas generally include highway, powerline, and other rights-of-way, wildlife openings in forests, industrial sites, fencelines, and other similar areas
  • Non-selective Herbicide – A herbicide that is generally toxic to all treated plants. Some selective herbicides become non-selective when applied at high rates
  • Nontarget – Any plant, animal, or other organism that a method of application is not aimed to affect, but which may be accidentally injured during application
  • n.o.s – Not otherwise specified
  • Noxious Weed – A weed regulated or specified by law as being especially undesirable, troublesome, and difficult to control
  • NRC – National Response Center (1-800-424-8802). Also…the National Research Council (Clarified by context)
  • NTIS – National Technical Information Service
  • NTP – National Toxicology Program
  • Nymph – The early (immature) stages in the development of insects undergoing gradual metamorphosis (which lack a larval stage)

O

  • Oil – A liquid aromatic or paraffinic hydrocarbon compound. Oil may be used as an active ingredient (dormant oils) but they are more commonly used as inert diluents or carriers for other pesticides
  • Oncogenic – Causing tumor formation; cancer causing
  • One-hundred-fold Margin of Safety (1/2) – The safety factor suggested by the EPA as adequate to pose only a low risk to the typical (average) member of the human population. It is equivalent to the (NOEL / 100 / the dose)
  • One-hundred-fold Margin of Safety (2/2) – In order to satisfy the criterion which has been adopted as a standard in Region 8, the value returned by this formula must be greater than or equal to 1.0 for both human and wildlife analyses
  • OPP – Office of Pesticide Programs, U.S. EPA
  • OPPE – Office of Policy Planning and Evaluation, U.S. EPA
  • OPTS – Office of Pesticides and Toxic Substances, U.S. EPA
  • Oral Exposure – Exposure of an organism to a pesticide or other substance through the mouth, throat or stomach
  • ORD – Office of Research and Development, U.S. EPA
  • Organic Compound – Any chemical compound which contains carbon
  • Organochlorine – A family of organic chemicals (contain carbon) which are distinguished by containing chlorine. Often, very persistent in the environment; examples include chlordane, lindane, and DDT. See also…Chlorinated hydrocarbon
  • Organophosphate – A family of organic chemicals (contain carbon) which are distinguished by containing one or more phosphorous atoms in their structure. Generally less persistent than organochlorines; all inhibit the action of cholinesterase, a blood clotting chemical. Examples include malathion, diazinon and parathion
  • Orifice – The opening in a nozzle tip through which liquid is forced to produce a continuous stream or a stream of droplets
  • OSHA or O.S.H.A. – Occupational Safety and Health Administration or Occupational Safety and Health Act of 1970 as amended (Meaning is context dependant)
  • OST – Office of Science and Technology, U.S. EPA
  • OSWER – Office of Solid Waste and Emergency Response, U.S. EPA
  • OTS – Office of Toxic Substances, U.S. EPA
  • Ovicide – A chemical designed to kill animal eggs
  • Over-the-top Application – A broadcast, banded or spot application made over the canopy of the crop trees (generally seedlings)
  • OWRS – Office of Water Regulations and Standards, U.S. EPA
  • oz – Ounce(s)
  • Occupational Exposure Limit (OEL) – Generally, a (legally enforceable) limit on the amount or concentration of a chemical to which a worker may be exposed. See also…AEL, MEL, PEL, STEL, TLV, TWA

P

  • Pathogen – An organism capable of causing disease
  • Pellet – Dry formulation of pesticide and other components in discrete particles usually larger than 10 cubic millimeters designed to be applied without a liquid carrier
  • Penetration – The process of entering, as in entering a leaf or stem
  • Perennial Plant – A plant (species) having a lifespan of more than two years. See also...Annual, Biennial
  • Permissible Exposure Limit (PEL) – A TWA or an absolute value, usually a regulatory value, which is the maximum permitted exposure to a hazardous chemical. See also…AEL, MEL, OEL, STEL, TLV, TWA
  • Persistence – The resistance of a herbicide to metabolic or environmental degradation or removal; a measure of the duration of retention of activity by a pesticide in the environment
  • Personnel Protective Equipment (PPE) – Apparel and devices worn to protect the body from contact with pesticides or pesticide residues, including: coveralls; chemical-resistant suits, gloves, footwear, aprons, and headgear; protective eyewear; and, respirators (per WPS). In addition, labels may require long sleeved shirts, long pants, shoes and socks, and other items which are not specifically designated as PPE
  • Pesticide (FIFRA definition) – Any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest, and (2) any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant. [Note: the definition then excludes certain animal drugs controlled by other laws.]
  • Pesticide Interaction – The action or influence of one pesticide on another and the combined effect of the pesticides on the pest(s) or the crop
  • pH – A measurement scale used to express acidity or alkalinity of a solution; pH 7.0 is neutral, pHs <7 are relatively more acidic as the value approaches 0, and pHs >7 become relatively more alkaline as the value approaches 14
  • Phenoxy Herbicide – A chemical family of herbicides typified by having a benzene ring as its base and a methyl group as a side chain connected to the benzene ring by an oxygen atom. In addition, all phenoxies have one to three chlorines linked separately to the benzene ring. Phenoxy herbicides act as plant growth inhibitors, generally showing an auxin type of growth inhibition often expressed at low doses as epinasty. Phenoxies include 2,4-D, 2,4,5-T 2,4-DB,2,4-DP and MCPA
  • Pheromone – A chemical produced by an organism to either attract or repel members of the same species. Artificially produced pheromones are used to disrupt populations of insects often by disrupting mating patterns, or as baits to trap insects
  • Photodecomposition – The breakdown of a complex substance (generally a chemical compound) into simpler components by the action of radiant energy
  • Photolysis – Breaking down of a compound as a result of the action of radiant energy in the visible spectrum
  • Phytolysis – Breakdown of a compound or substance by plant biochemical action
  • Phytotoxic – Injurious or lethal to plants
  • Piscicide – A pesticide used to control fish
  • Plant Growth Regulator – A substance used for controlling or modifying plant growth processes without causing severe phytotoxicity
  • Poison – Any chemical or agent which is capable of causing illness or death when eaten, absorbed through the skin, inhaled, or otherwise absorbed by man, animals or plants; substances are poisonous with respect to specific organisms, few, if any, are universally poisonous. For regulatory purposes the word POISON means any pesticide having an oral LD50 less than or equal to 50 mg/kg; a ‘highly toxic’ chemical
  • Postemergence – After the emergence of a specified weed or planted crop. Refers to application of a pesticide after the plant emerges from the soil
  • Potable Water – Water suitable and intended for human consumption
  • ppb – Parts per billion; equaling 1/1,000,000,000 or 1 x 10-9.
  • ppm – Parts per million; equaling 1/1,000,000 or 1 x 10-6
  • ppt – Parts per trillion; equaling 1/1,000,000,000,000 or 1 x 10-12
  • Predicide – A pesticide used to control vertebrate predator pests
  • Predator – An insect or other animal that attacks, feeds on, and destroys other animals (including insects)
  • Preemergence – Before the emergence of a specified weed or planted crop. Refers to the application of a pesticide before the plant emerges from the soil
  • Private Applicator(FIFRA meaning) – Any certified applicator who uses or supervises the use of any pesticide which is classified for restricted-use for the purpose of producing any agricultural commodity on property owned or rented by the applicator or his/her employer, or applied (if applied without compensation other than trading of personal services between producers of agricultural commodities) on the property of another person. See also…Certified applicator, Commercial applicator
  • Protocol – A clearly described, generally accepted, repeatable method used in evaluating any specific endpoint
  • p.s.i. or psi – Pounds (of pressure) per square inch of surface
  • pt – Pint(s)
  • Pupa – The resting stage of insects which undergo complete metamorphosis which occurs as the transition stage during which the insect matures from the larval to the adult stage. See also…Complete metamorphosis
  • PVC – Polyvinyl chloride
  • Pyrolysis – Chemical breakdown caused by fire

Q

  • qt – Quart(s)

R

  • Rate – The quantity of active ingredient (ai) or parent compound equivalent (ae) expressed as mass per unit area (surface or volume) treated; for example lbs ai/ac or gm ae/ml
  • RCRA – Resource Conservation and Recovery Act of 1976 as amended
  • Ready-to-use Formulation of a Pesticide (RTU) – A pesticide which, as formulated by the manufacturer and sold in stores, is designed to be used ‘as-is’ without further dilution or mixing with other chemicals. See also…Formulated product, Technical grade
  • Reregistration Eligibility Document (RED) – A document prepared by the EPA which summarizes their conclusions about their risk assessment of a pesticide and outlines any risk management measures necessary for the pesticide to continue to be registered in the USSee also…IRED, TRED
  • Reference Dose (RfD) – An estimate of daily oral exposure to the human population (including sensitive subgroups) that is likely to be without deleterious effects during a lifetime. Uncertainty associated with this estimate may span an order of magnitude; uncertainty factors are generally applied to these estimates to reflect the limitations of the data used to derive the estimates. See also…Hazard Quotient
  • Registered Pesticide – A pesticide that has been registered with the Environmental Protection Agency for use in the United States under authority granted in FIFRA. See…Registration
  • Registration – The process whereby a pesticide is approved for specified uses in the United States by the Environmental Protection Agency under the authority of FIFRA. As part of the registration process, the EPA assigns a registration number and approves adequate company-prepared labels. See..EPA registration number, Label, Registered pesticide
  • Release – The process of allowing desirable vegetation greater access to soil moisture, nutrients, and light by reducing or eliminating competing vegetation on a site. See also…Thinning
  • Repellent – A pesticide used too keep animal pests away or to deter their activity
  • Reportable Quantity (RQ) – The minimum amount of spilled HAZMAT which must, under federal law, be reported to the NRC
  • Reptile – Vertebrate animals that are cold-blooded and possess scaly skin, for example snakes, turtles and lizards
  • Residual Pesticide – The quantity of a herbicide or its metabolites remaining active in soil, water, plants, animals, or on their surfaces; a herbicide that persists, remaining active, in the soil for a relatively short period of time
  • Residue – The amount of pesticide that remains on or in agricultural products
  • Residue Tolerance – The concentration of a pesticide residue that is allowed in or on raw agricultural commodities as established by the EPA. See also…Tolerance
  • Resistance – The ability to withstand exposure to a potentially harmful agent without being injured. (There is no general agreement as to the distinction between herbicide tolerance and herbicide resistance in plants). See also…Tolerance
  • Respirator – A device worn over the nose and mouth which filters air being breathed so as to protect the respiratory tract from damaging agents (noxious fumes, pesticidal dusts, etc.)
  • Restricted-Entry Interval (REI;under WPS) – The time after a pesticide application during which entry to the site is limited by law. The most common limitation imposed is that specified PPE is required to be worn by a worker or handler if they must reenter the area during the REI. REIs are specified on the pesticide label as are PPE requirements for early reentry
  • Restricted-use Pesticide – A pesticide product for application only by certified applicators or persons under their direct supervision. Designation of ‘restricted-use’ generally reflects environmental or public health concerns which require a higher degree of care than is acceptable for the application of general-use pesticides. Legally specified records of use are required to be kept and maintained when using restricted use pesticides. See also…General-use pesticide
  • Rhizome – A rootlike underground stem
  • Right-of-way (ROW) – Areas involved in common transport, including highways, roads, railroads, powerlines, pipelines, waterways, trails, and paths
  • Risk – The probability that a substance or its lack, an action or lack of action, or some other stimulus or lack of stimulus will produce harm under specified conditions
  • Risk Assessment (RA) – The determination of potential adverse health effects from exposure to chemicals, which includes both quantitative and qualitative expressions of risk. The term applies to both the process of evaluating risk and the written documentation produced
  • Risk Management – A decision making process that accounts for political, social, economic and engineering implications together with risk-related information in order to develop, analyze and compare management options and select the appropriate managerial response to a potential chronic health hazard
  • Rodent – Any animal in the taxonomic Order Rodentia; examples include rats, mice, rabbits, squirrels, and beavers
  • Rodenticide – A pesticide used for rodent control
  • S

    • SAB – Science Advisory Board. See also…SAP
    • Safener – A substance which reduces toxicity of herbicides to crop plants by a physiological means
    • Safety factor – A number representing human tolerance for a chemical agent based on the NOEL determined in animal testing
    • SAP – U.S. EPA OPP’s FIFRA Scientific Advisory Panel which provides advice regarding pesticide regulation, guidance and registration actions Compare with…SAB
    • SARA – Superfund Amendment and Reauthorization Act of 1986 as amended
    • SDWA – The Safe Drinking Water Amendments of 1977 as amended. This is an amendment to Section 8 of the Public Health Service Act
    • sec – Second
    • Sedge – Any of the numerous grasslike vascular plants which have a solid (often square in cross section) stem as differentiated from the round hollow stem which typifies grasses. Sedges are classified in the family Cyperaceae
    • Seed Protectant – A chemical applied to seeds before planting to protect seeds and/or seedlings from pests; most commonly a fungicide, insecticide, or repellant
    • Selective Herbicide – A pesticide that is more toxic to some plant species than to others
    • Sensitive Subgroup – Subpopulation which is more vulnerable to suffering negative effects from exposure to specific agents in the environment than are the average members of the population
    • Sensitization – The process by which a living organism becomes allergic to a stimulus
    • Short-term Exposure – Multiple or continuous exposure to an agent for a short period of time, usually one week or less
    • Short Term Exposure Limit (STEL) – The maximum permissible concentration of a chemical (generally as ppm in air) for a defined short period of time (generally 5 minutes). Normally backed by regulation, they are legally enforceable limits. See…AEL, MEL, OEL, PEL, TLV, TWA
    • Signal Word – One of three words (DANGER, WARNING, CAUTION) defined by law which must appear prominently on a pesticide label to indicate the relative toxicity of the product
    • Silvicide – A pesticide used to kill unwanted brush and trees (a subset of herbicide)
    • Site (per FIFRA) – The area(s) of land or water defined on the product label to which a pesticide may be applied. Under the 1988 reauthorization of FIFRA the site of application must be present on the label in order for an applicator to legally apply that pesticide on that site
    • Site Preparation – Preparation of an area for planting or natural regeneration, may involve herbicidal application to removal of potentially competing plant growth
    • Slurry – Thin watery mixture of dirt or clay (and often a pesticide) into which seedling roots are dipped to provide protection during cold storage or during early outplanting
    • Soil-active – A herbicide which, when applied to or present in the soil, is readily absorbed by plant roots and subsequently negatively affects the plant
    • Soil Injection – Placement of a herbicide beneath the soil surface with a minimum of mixing or stirring of the soil, as with an injection blade, knife, or tine
    • sol – Solubility or soluble (depending on context)
    • Soluble Concentrate(S) – A liquid formulation which forms a solution when added to water
    • Soluble Granule (SG) – A dry granular formulation which forms a solution when added to water
    • Soluble Powder (SP) – A finely divided dry pesticide formulation that dissolves in water
    • Solution – A liquid or solid chemical dissolved (not suspended) in water. Also, an ester or other oil-soluble chemical dissolved in oil
    • sp – Specific (as in sp grav = specific gravity) or species (depending on context)
    • Special Local Need Registration (SLN of a pesticide) – Registration of a pesticide by U.S. EPA which allows its use in a single state for a stated purpose and generally for a limited time
    • Spot Treatment – Pesticide application to restricted portions (or spots) within a larger unit
    • sq – Square
    • Stolon – A horizontal branch from the base of a plant which produces new plants from buds at its tip. Also called a runner
    • Streamline – A basal herbicide application in which a stream of liquid herbicide mixture is directed at each individual targeted stem until it is visibly wet (generally by 2-5 ml of the mixture). The herbicide is normally diluted in the application mixture. See also…Thinline
    • Stylet – A small, hypodermic-like mouth structure of nematodes used to pierce plant or animal tissue for the purposes of feeding
    • Subchronic Exposure – Exposure to a substance spanning about 10% of the lifespan of an organism. (Exposures of longer duration than acute or short-term and shorter than chronic)
    • Submersed Plant (Submegent) – A rooted aquatic or marine plant that grows with all or almost all of its vegetative surface below the surface of the water. See also…Emergents, Floaters, Immersed Plants
    • Sufficient Challenge – The theory that exposure to very small amounts of a foreign chemical may stimulate the body’s defense mechanisms and make the body stronger
    • Sulfonylurea – Organic herbicide family with a sulfur containing urea bridge between two benzene rings – one of which has N substituted for C at 2 or 3 locations on the ring. They inhibit amino acid synthesis in roots and shoots. Included here are Oust (sulfometuron methyl) and Escort (metsulfuron methyl)
    • Superfund – Federal authority, established under CERCLA, to respond directly to releases or threatened releases of hazardous substances that may endanger the environment
    • Surface Acre – Surface area of water equal to 43,560 square feet. See also…Acre foot
    • Surfactant – A material that favors or improves the emulsifying, dispersing, spreading, or wetting, properties of a liquid
    • Susceptibility – The sensitivity to or degree to which a plant is injured by a herbicidal treatment. Also, the degree to which a potential host is vulnerable to attack by a pathogen, or a population or individual is vulnerable to insect attack. (Meaning from context)
    • Suspend (FIFRA regulatory action) – To revoke one or all registered use(s) of a pesticide with the requirement that no further use be made of the chemical. Suspension immediately revokes all permissions formerly allowed which are listed (as voided) in the suspension order. See also…Cancel
    • Suspension – Finely divided solid particles or liquid droplets dispersed in a solid, liquid, or gas
    • Swath – A linear treated area the width of a single pass of a sprayer boom
    • Synergism – The effect produced by two chemicals applied together where the total response is greater than the sum of their independent effects. See also…Additive effect, Antagonism
    • Synthetic Chemical – A chemical made in a laboratory or industrial plant
    • Systemic Pesticide – A pesticide which, when introduced into an organism, is moved to another part of that organism where it acts against the pest; most correctly used to describe the action of fungicides or insecticides. See also…Contact herbicide, Contact insecticide, Translocated herbicide
    • Subchronic Toxicity – Toxicity of a substance expressed iafter multiple doses given for longer than a day and less than half of the projected life expectancy of the test individuals. See also…Acute toxicity, Chronic toxicity

    T

    • Tank Mix – A combination of two or more formulated pesticides mixed together after purchase and prior to application
    • Technical Grade – An active ingredient as produced by a manufacturer prior to formulation and packaging as a pesticidal product. See also…Formulated product, Ready-to-Use
    • Teratogen – An agent capable of producing damage to an embryo which results in birth defects
    • Teratogenic – Capable of causing structural defect in offspring, generally acting during the development of individual organs; capable of causing birth defects
    • Thinline – A basal herbicide application in which a thin stream of undiluted herbicide is directed at groups of target plants. The applicator uses a side-to-side motion of the nozzle to achieve the desired stem coverage. See also…Streamline
    • Thinning – The process of selectively removing undesirable or less desirable plants to improve the average growth rate and form of the remaining plants. May be done in a variety of ways, with or without the use of herbicide. See also…Release
    • Threshold – A dose or exposure level below which no deleterious effect is expected to occur
    • Threshold limit value (TLV) – The average concentration of airborne contaminants in mg/m3 for an 8-hour workday and a 40 hour work week to which nearly all workers may be repeatedly exposed, day after day, without adverse effects. TLV guidelines are published by the ACGIH. See also…AEL, MEL, OEL, PEL, STEL, TWA
    • Thiocarbamate – A subset of the carbamate insecticides which has a sulfur atom substituted for an oxygen atom in the linking of the carboxyl group. Includes eptam
    • Time Weighted Average (TWA) – The average concentration of a chemical to which it is permissible to expose a worker over a specified period of time (generally 8 hours). See also…AEL, MEL, OEL, PEL, STEL, TLV
    • Tolerance – The ability to continue normal growth when exposed to a potentially harmful agent. See also…Resistance, Residue tolerance
    • Toxicity – The natural capacity of a substance to produce injury to an organism; may vary by route of exposure
    • Toxicology – The study of harmful interactions between chemicals and biological systems
    • Toxic Substance – A chemical substance or agent which may cause an adverse effect or effects to biological systems
    • TRAC – US EPA’s Tolerance Reassessment Advisory Committee
    • Trade Name (Product name) – A brand name, trademark or other designation by which a commercial product is identified. See also…Chemical name, Common name. Return to…Name, Product name
    • Translocated Herbicide – A herbicide that is moved within a plant from the point of application to the point of action; may be either phloem-mobile or xylem-mobile. However, the term is often restricted to mean a foliar applied herbicide which moves downward from the leaves to the roots. See also…Contact herbicide, Systemic pesticicide
    • Triazine – A fungicide which is formed of a substituted benzene ring base in which alternating carbons in the ring have been replaced by a nitrogen atom giving a C3N3 ring rather than the C6 ring as in benzene. Triazines interfere with protein synthesis and chloroplast development. Examples include atrazine and simazine
    • TSCA – Toxic Substances Control Act of 1976 as amended
    • Tumor – An abnormal, uncontrolled growth of cells. Synonym = Neoplasm
    • Tolerance/Reregistration Eligibility Document (TRED) 1/2 – A document issued by the EPA for a pesticide requiring a tolerance reassessment under FQPA, but not needing a REDfor one of three reasons – Contd. See also...IRED, RED
    • Tolerance/Reregistration Eligibility Document (TRED) 2/2 – Reasons for issuance of a TRED and not a full RED include: Pesticide initially registered after Nov. 1, 1984 and not subject to reregistration
    • RED completed for pesticide prior to August 3, 1996 when FQPA was enacted
    • Pesticide not registered for use in the US; import tolerance only

    U

    • UFL – Upper flammability limit
    • ug – Microgram; 1/1,000 of a gram. Return to…Microgram
    • Ultra Low Volume (ULV) – Applications of very small amounts of undiluted pesticide (1/2 pint or less, or an equivalent amount of undiluted dry material) per acre
    • Ultra Light Weight Granular Formulation (ULW) – A formulation produced as extremely fine granules and designed for aerial application by specialized blowers
    • Uncertainty factor (UF) 1/3 – One of several (up to) 10-fold factors, used to derive an RfD from experimental data. UFs are intended to account for: (1) the variation in sensitivity among the members of the human population (intraspecies variation); ---Contd
    • Uncertainty factor (UF) 2/3 – UFs are intended to account for: (2) the uncertainty in extrapolating animal data to humans (interspecies variability); (3) the uncertainty in extrapolating from data obtained in a study with less than lifetime exposure to project lifetime exposure; ---Contd
    • Uncertainty factor (UF) 3/3 – UFs are intended to account for: (4) the uncertainty from extrapolating from a LOAEL rather than from a NOAEL; and, (5) the uncertainty associated with extrapolating from an incomplete data base (incomplete or unavailable data)
    • United Nations/North America Number (UN/NA No.) – A unique 4-digit number applied to a chemical for identification and tracking purposes by the U.N
    • United States Patent Number (U.S. Pat. No.) – A unique number assigned by the United States Patent Office which protects the holder of the patent from production by unlicensed persons or companies in the US
    • Upper Bound – A plausible upper limit to the true value of a quantity. This is usually not a true statistical limit with confidence interval
    • USDA – U.S. Department of Agriculture
    • USDA FS – U.S. Department of Agriculture, Forest Service

    V

    • vap – Vapor
    • Vascular Plant – A plant with specialized conducting cells (xylem and phloem) that convey water and food throughout the plant
    • Vector – A carrier, such as an insect, that transmits a pathogen
    • Vertebrate – An animal with a bony spine
    • Volatile – Evaporating at normal temperature and pressure
    • Volatility – The ability of a solid or liquid to evaporate at normal temperature and pressure; readily vaporized

    W

    • Weed – Any plant that is objectionable or interferes with the activities or welfare of man; any plant that is ‘out of place’ by the observers definition
    • Weed Control – The process of reducing weed growth or infestation to an acceptable level
    • Weed Eradication – The elimination of all vegetative plant parts and viable seeds of a weed from a site
    • Wettable Granular (WG) – A dry pesticide formulation of discrete particles 10 mm3 or larger designed to be suspended in water for the purposes of application
    • Wettable Powder (WP) – A finely divided dry pesticide formulation that can be suspended readily in water
    • Wetting Agent – A chemical that helps a pesticide spread and coat (wet) a surface more evenly. Wetting agents reduce the amount of a spray that rolls off smooth or waxy leaves, and helps sprays to spread out on hairy leaves. Detergents are sometimes used as wetting agents
    • Worker (WPS description) – A worker is anyone who: (1) is employed (including self-employed) for any type of compensation and (2) is doing tasks such as harvesting, weeding, or watering, relating to the production of agricultural plants on a farm, forest, nursery, or greenhouse. The term does NOT include persons who are employed by a commercial establishment to perform tasks as crop advisors. See also…Crop Advisor, Handler
    • Worker Protection Standard (WPS) – U.S. EPA regulations enacted in 1992 intended to protect agricultural and forestry workers from exposure to pesticides, as specified in 40 CFR Part 170
    • WSSA – Weed Science Society of America
    • wt or wgt – Weight

    X

    • None at Present

    Y

    • None at Present

    Z

    • None at Present

    [  Contents  ]

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    University of GeorgiaThe Bugwood Network Forestry Images The Bugwood Network and Forestry Images Image Archive and Database Systems
    The University of Georgia - Warnell School of Forestry and Natural Resources and
    College of Agricultural and Environmental Sciences - Dept. of Entomology
    Last updated on Thursday, October 31, 2002 at 01:19 PM
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