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Pesticide Dictionary

Pesticide Dictionary


Index:

Dictionary:
|A|B|C|D|E|F|G|H|I|L|M|N|O|P|R|S|T|U|V|W|

Other Terms Relating To Toxic Substances
 

A.
AAPCO.
Association of American Pesticide Control Officials, Inc.
Abscission.
Process by which a leaf or other part is separated from the plant.
Absorption.
Process by which pesticides are taken into tissues, namely plants, by roots or foliage (stomata, cuticle, etc.).
Acaricide (miticide).
An agent that destroys mites and ticks.
Acetylcholine (ACh).
Chemical transmitter of nerve and nerve-muscle impulses in animals.
Activator.
Material added to a fungicide to increase toxicity.
Active ingredient (a.i. or AI).
Chemicals in a product that are responsible for the pesticidal effect.
Acute toxicity.
The toxicity of a material determined at the end of 24 hours; to cause injury or death from a single dose or exposure.
Adjuvant.
An ingredient that improves the properties of a pesticide formulation. Includes wetting agents, spreaders, emulsifiers, dispersing agents, foam suppressants, penetrants, and correctives.
Adsorption.
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.
Aerosol.
Colloidal suspension of solids or liquids in air.
Adulterated pesticide.
A pesticide that does not conform to the professed standard or quality as documented on its label or labeling.
Agroecosystem.
An agricultural area sufficiently large to permit long-term interactions of all the living organisms and their nonliving environment.
Algicide.
Chemical used to control algae and aquatic weeds.
Alkylating agent.
Highly active compounds (chemosterilants) that replace hydrogen atoms with alkyl groups, usually in cells undergoing division.
Annual.
Plant that completes its life cycle in one year, i.e., 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.
Chemical substance produced by a microorganism and that is toxic to other microorganisms.
Anticoagulant.
A chemical that prevents normal bloodclotting. The active ingredient in some rodenticides.
Antidote.
A practical treatment, including first aid, used in the treatment of pesticide poisoning or some other poison in the body.
Antimetabolite.
Chemicals that are structurally similar to biologically active metabolites, and that may take their place detrimentally in a biological rection.
Antitranspirant.
A chemical applied directly to a plant that reducesthe rate of transpiration of water loss by the plant.
Apiculture.
Pertaining to the care and culture of bees.
Aromatics.
Solvents containing benzene or compounds derived from benzene.
Atropine (atropine sulfate).
An antidote used to treat organophosphate and carbamate poisoning.
Attractant, insect.
A substance that lures insects to trap or poison-bait stations. Usually classed as food, oviposition, and sex attractants.
Auxin.
Substance found in plants that stimulates cell growth in plant tissues.
Avicide.
Lethal agent used to destroy birds but also refers to materials used for repelling birds.
Aziridine.
Chemical classification of chemosterilants containing three-membered rings composed of one nitrogen and two carbon atoms.


B.
Bactericide.
Any bacteria-killing chemical.
Bacteriostat.
Material used to prevent growth or multiplication of bacteria.
Band application.
Application to a continuous restricted band such as in or along a crop row, rather than over the entire field area.
Biennial.
Plant that completes its growth in 2 years. The first year it produces leaves and stores food; the second year it produces fruit and seeds.
Biological control agent.
Any biological agent that adversely affects pest species.
Biomagnification.
The increase in concentration of a pollutant in animals as related to their position in a food chain, usually referring to the persistent, organochlorine insecticides and their metabolites.
Biota.
Animals and plants of a given habitat.
Biotic insecticide.
Usually microorganisms known as insect pathogens that are applied in the same manner as conventional insecticides to control pest species.
Biotype.
Subgroup within a species differing in some respect from the species such as a subgroup that is capable of reproducing on a resistant variety.
Botanical pesticide.
A pesticide produced from naturally occurring chemicals found in some plants. Examples are nicotine, pyrethrum, strychnine, and rotenone.
Brand.
The name, number, or designation of a pesticide.
Broadcast application.
Application over an entire area rather than only on rows, beds, or middles.
Broad-spectrum insecticide.
Nonselective, having about the same toxicity to most insects.


C.
Calibrate.
To determine the amount of pesticide that will be applied to the target area.
Carbamate insecticide.
One of a class of insecticides derived from carbamic acid.
Carcinogen.
A substance that causes cancer in animal tissue.
Carrier.
An inert material that serves as a diluent or vehicle for the active ingredient or toxicant.
Causal organism.
The organism (pathogen) that produces a given disease.
Certified applicator.
Commercial or private person qualified to apply restricted-use pesticides as defined by the EPA.
Chelating agent.
Certain organic chemicals (i.e., ethylenediaminetetraacetic acid) that combine with metal to form soluble chelates and prevent conversion to insoluble compounds.
Chemical name.
Scientific name of the active ingredient(s) found in the formulated product. The name is derived from the chemical structure of the active ingredient.
Chemosterilant.
Chemical compounds that cause sterilization or prevent effective reproduction.
Chemotherapy.
Treatment of a diseased organism, usually plants, with chemicals to destroy or inactivate a pathogen without seriously affecting the host.
Chemtrec.
A toll-free, long-distance, telephone service that provides 24-hour emergency pesticide information (800-424-9300).
Chlorosis.
Loss of green color in foliage.
Cholinesterase (ChE).
An enzyme of the body necessary for proper nerve function that is inhibited or damaged by organophosphate or carbamate insecticides taken into the body by any route.
Chronic toxicity.
The toxicity of a material determined beyond 24 hours and usually after several weeks of exposure.
Common pesticide name.
A common chemical name given to a pesticide by a recognized committee on pesticide nomenclature. Many pesticides are known by a number of trade or brand names but have only one recognized common name. For example, the common name for Sevin insecticide is carbaryl.
Compatible. Compatibility.
When two materials can be mixed together with neither affecting the action of the other.
Concentration.
Content of a pesticide in a liquid or dust; for example, pounds/gallon or percent by weight.
Contact herbicide.
Phytotoxin by contact with plant tissue rather than as a result of translocation.
Contamination.
The presence of an unwanted pesticide or other material in or on a plant, animal, or their by-products; soil; water; air; structure; etc. (See Residue).
Cumulative pesticides.
Those chemicals that tend to accumulate or build up in the tissues of animals or in the environment (soil, water).
Curative pesticide.
A pesticide that can inhibit or eradicate a disease-causing organism after it has become established in the plant or animal.
Cutaneous toxicity.
Same as dermal toxicity.
Cuticle.
Outer covering of insects.


D.
Deciduous.
Plants that lose their leaves during the winter.
Decontaminate.
The removal or breakdown of any pesticide chemical from any surface or piece of equipment.
Deflocculating agent.
Material added to a spray preparation to prevent aggregation or sedimentation of the solid particles.
Defoliant.
A chemical that initiates abscission.
Deposit.
Quantity of a pesticide deposited on a unit area.
Dermal toxicity.
Toxicity of a material as tested on the skin, usually on the shaved belly of a rabbit; the property of a pesticide to poison an animal or human when absorbed through the skin.
Desiccant.
A chemical that induces rapid desiccation of a leaf or plant part.
Desiccation.
Accelerated drying of plant or plant parts.
Detoxify.
To make an active ingredient in a pesticide or other poisonous chemical harmless and incapable of being toxic to plants and animals.
Diluent.
Component of a dust or spray that dilutes the active ingredient.
Disinfectant.
A chemical or other agent that kills or inactivates disease-producing microorganisms in animals, seeds, or other plant parts. Also commonly refers to chemicals used to clean or surface sterilize inanimate objects.
DNA.
Deoxyribonucleic acid.
Dormant spray.
Chemical applied in winter or very early spring before treated plants have started active growth.
Dose, dosage.
Same as rate. The amount of toxicant given or applied per unit of plant, animal, or surface.
Drift, spray.
Movement of airborne spray droplets from the spray nozzle beyond the intended contact area.


E.
EC50.
The median effective concentration (ppm or ppb) of the toxicant in the environment (usually water) that produces a designated effect in 50 percent of the test organisms exposed.
Ecdysome.
Hormone secreted by insects essential to the process of molting from one stage to the next.
Ecology.
Derived from the Greek oikos,house or place to live A branch of biology concerned with organisms and their relation to the environment.
Economic level.
The insect pest level at which additional management practices must be employed to prevent economic losses.
Ecosystem.
The interacting system of all the living organisms of an area and their nonliving environment.
ED50.
The median effective dose, expressed as mg/kg of body weight, which produces a designated effect in 50 percent of the test organisms exposed.
Emulsifiable concentrate.
Concentrated pesticide formulation containing organic solvent and emulsifier to facilitate emulsification with water.
Emulsifier.
Surface active substances used to stablize suspensions of one liquid in another; for example, oil in water.
Emulsion.
Suspension of miniscule droplets of one liquid in another.
Environment.
All the organic and inorganic features that surround and affect a particular organism or group of organisms.
EPA.
The Environmental Protection Agency.
Environmental Protection Agency (EPA).
The federal agency responsible for pesticide rules and regulations, and all pesticide registrations.
EPA Establishment Number.
A number assigned to each pesticide production plant by EPA. The number indicates the plant at which the pesticide product was produced and must appear on all labels of that product.
EPA Registration Number.
A number assigned to a pesticide product by EPA when the product is registered by the manufacturer or his designated agent. The number must appear on all labels for a particular product.
Eradicant.
Applies to fungicides in which a chemical is used to eliminate a pathogen from its host or environment.
Exterminate.
Often used to imply the complete extinction of a species


F.
FEPCA.
The Federal Environmental Pesticide Control Act of 1972.
Field scout.
A person who samples fields for insect infestations.
FIFRA.
The Federal Insecticide, Fungicide and Rodenticide Act of 1947.
Filler.
Diluent in powder form.
Fixed coppers.
Insoluble copper fungicides where the copper is in a combined form. Usually finely divided, relatively insoluble powders.
Flowable.
A type of pesticide formulation in which a very finely ground solid particle is mixed in a liquid carrier.
Foaming agent.
A chemical that causes a pesticide preparation to produce a thick foam. This aids in reducing drift.
Fog treatment.
The application of a pesticide as a fine mist for the control of pests.
Food chain.
Sequence of species within a community, each member of which serves as food for the species next higher in the chain.
Formamidine insecticide.
A new group with a new mode of action highly effective against insect eggs and mites.
Formulation.
Way in which basic pesticide is prepared for practical use. Includes preparation as wettable powder, granular, emulsifiable concentrate, etc.
Full-coverage spray.
Applied thoroughly over the crop to a point of runoff or drip.
Fumigant.
A volatile material that forms vapors that destroy insects, pathogens, and other pests.
Fungicide.
A chemical that kills fungi.
Fungistatic.
Action of a chemical that inhibits the germination of fungus spores while in contact.


G.
Gallonage.
Number of gallons of finished spray mix applied per acre, tree, hectare, square mile, or other unit.
General-use pesticide.
A pesticide that can be purchased and used by the general public without undue hazard to the applicator and environment as long as the instructions on the label are followed carefully. (See Restricted-use pesticide).
Growth regulator.
Organic substance effective in minute amounts for controlling or modifying (plant or insect) growth processes.


H.
Harvest intervals.
Period between last application of a pesticide to a crop and the harvest as permitted by law.
Hormone.
A product of living cells that circulates in the animal or plant fluids and that produces a specific effect on cell activity remote from its point of origin.
Hydrolysis.
Chemical process of (in this case) pesticide breakdown or decomposition involving a splitting of the molecule and addition of a water molecule.
Hyperplasia.
Abnormal increase in the number of cells of a tissue.
Hypertrophy.
Abnormal increase in the size of cells of a tissue.


I.
Incompatible.
Two or more materials that cannot be mixed or used together.
Ingest.
To eat or swallow.
Ingredient statement.
That portion of the label on a pesticide container that gives the name and amount of each active ingredient and the total amount of inert ingredients in the formulation.
Inhalation.
Exposure of test animals either to vapor or dust for a predetermined time.
Inhalation toxicity.
To be poisonous to man or animals when breathed into the lungs.
Insect-growth regulator (IGR).
Chemical substance that disrupts the action of insect hormones controlling molting, maturity from pupal stage to adult, and others.
Insect pest management.
The practical manipulation of insect (or mite) pest populations, using any or all control methods in a sound ecological manner.
Integrated control.
The integration of the chemical and biological control methods.
Integrated pest management.
A management system that uses all suitable techniques and methods in as compatible a manner as possible to maintain pest populations at levels below those causing economic injury.
Intramuscular.
Injected into the muscle.
Intraperitoneal.
Injected into the viscera but not into the organs.
Intravenous.
Injected into the vein.
Invert emulsion.
One in which the water is dispersed in oil rather than oil in water. Usually a thick mixture like salad dressing results.


L.
Label.
All printed material attached to or part of the pesticide container.
Labeling.
Supplemental pesticide information that complements the information on the label but is not necessarily attached to or part of the container.
LC50.
The median lethal concentration, the concentration that kills 50 percent of the test organisms, expressed as milligrams (mg) or cubic centimeters (cc, if liquid) per animal. It is also the concentration expressed as parts per million (ppm) or parts per billion (ppb) in the environment (usually water) that kills 50 percent of the test organisms exposed.
LD50.
A lethal dose for 50 percent of the test organisms. The dose of toxicant producing 50 percent mortality in a population. A value used in presenting mammalian toxicity, usually oral toxicity, expressed as milligrams of toxicant per kilogram of body weight (mg/kg).
Leaching.
The movement of a pesticide chemical or other substance downward through soil as a result of water movement.
Low-volume spray.
Concentrate spray, applied to uniformly cover the crop, but not as a full coverage to the point of runoff.


M.
mg/kg (milligrams per kilogram).
Used to designate the amount of toxicant required per kilogram of body weight of test organism to produce a designated effect, usually the amount necessary to kill 50 percent of the test animals.
Microbial insecticide.
A microorganism applied in the same way as conventional insecticides to control an existing pest population.
Mildew.
Fungus growth on a surface.
Miscible liquids.
Two or more liquids capable of being mixed in any proportions and of remaining mixed under normal conditions.
M.L.D.
Median lethal dose (LD50).
Molluscicide.
A chemical used to kill or control snails and slugs.
Mutagen.
Substance causing genes in an organism to mutate or change.
Mycoplasma.
A microorganism intermeditae in size between viruses and bacteria possessing many virus-like properties and not visible with a light microscope.


N.
Necrosis.
Death of tissue, plant or animal.
Nematicide.
Chemical used to kill nematodes.


O.
Oncogenic.
The property to produce tumors (not necessarily cancerous) in tissues. (See Carcinogenic.)
Oral toxicity.
Toxicity of a compound when given by mouth. Usually expressed as number of milligrams of chemical per kilogram of body weight of animal (white rat) when given orally in a single dose that kills 50 percent of the animals. The smaller the number, the greater the toxicity.
Organochlorine insecticide.
One of the many chlorinated insecticides, e.g., DDT, dieldrin, chlordane, BHC, Lindane, etc.
Organophosphate.
Class of insecticides (also one or two herbicides and fungicides) derived from phosphoric acid esters.
Ovicide.
A chemical that destroys an organism's eggs.


P.
Pathogen.
Any disease-producing organism or virus.
Perennial.
Plants that continue to live from year to year. Plants may be herbaceous or woody.
Persistence.
The quality of an insecticide to persist as an effective residue due to its low volatility and chemical stability, e.g., certain organochlorine insecticides.
Pesticide.
An economic poison defined in most state and federal laws as any substance used for controlling, preventing, destroying, repelling, or mitigating any pest. Includes fungicides, herbicides, insecticides, nematicides, rodenticides, desiccants, defoliants, plant growth regulators, etc.
Pheromones.
Highly potent insect sex attractants produced by the insects. For some species laboratory-synthesized pheromones have been developed for trapping purposes.
Physical selectivity.
Refers to the use of broad-spectrum insecticides in such ways as to obtain selective action. This may be accomplished by timing, dosage, formulation, etc.
Physiological selectivity.
Refers to insecticides that are inherently more toxic to some insects than to others.
Phytotoxic.
Injurious to plants.
Piscicide.
Chemicals used to kill fish.
Poison.
Any chemical or agent that can cause illness or death when eaten, absorbed through the skin, or inhaled by humans or animals.
Poison control center.
Information sources for human poisoning cases, including pesticides, usually located at major hospitals.
Postemergence.
After emergence of the specified weed or crop.
ppb.
Parts per billion (parts in 10 x 9 parts) is the number of parts of toxicant per billion parts of the substance in question.
ppm.
Parts per million (parts in 10 x 6 parts) is the number of parts of toxicant per million parts of the substance in question. They may include residues in soil, water, or whole animals.
Predacide.
Chemicals used to poison predators.
Preplanting treatment.
Made before the crop is planted.
Propellant.
An inert ingredient in self-pressurized products that produces the force necessary to dispense the active ingredient from the container. (See Aerosol.)
Protectant.
Fungicide applied to plant surface before pathogen attack to prevent penetration and subsequent infection.
Protective clothing.
Clothing to be worn in pesticide-treated fields under certain conditions as required by federal law, e.g., reentry intervals.
Protopam chloride (2-pam).
An antidote for certain organophosphate pesticide poisoning, but not for carbamate poisoning.


R.
Rate.
Refers to the amount of pesticide active ingredient applied to a unit area regardless of percentage of chemical in the carrier (dilution).
Raw agricultural commodity.
Any food in its raw and natural state, including fruits, vegetables, nuts, eggs, raw milk, and meats.
Reentry (intervals).
Waiting interval required by federal law between application of certain hazardous pesticides to crops and the entrance of workers into those crops without protective clothing.
Registered pesticides.
Pesticide products that have been approved by the Environmental Protection Agency for the uses listed on the label.
Repellent (insets).
Substance used to repel ticks, chiggers, gnats, flies, mosquitoes, and fleas.
Residual.
Having a continued killing effect over a period of time.
Residue.
Trace of a pesticide and its metabolites remaining on and in a crop, soil, or water.
Resistance (insecticide).
Natural or genetic ability of an organism to tolerate the poisonous effects of a toxicant.
Restricted-use pesticide.
One of several pesticides, designated by the EPA, that can be applied only by certified applicators, because of their inherent toxicity or potential hazard to the environment.
RNA.
Ribonucleic acid.
Rodenticide.
Pesticide applied as a bait, dust, or fumigant to destroy or repel rodents and other animals, such as moles and rabbits.


S.
Safener.
Chemical that reduces the phytotoxicity of another chemical.
Secondary pest.
A pest that usually does little if any damage but can become a serious pest under certain conditions, e.g., when insecticide applications destroy a given insect's predators and parasites.
Selective insecticide.
One that kills selected insects, but spares many or most of the other organisms, including beneficial species, either through different toxic action or the manner in which insecticide is used.
Selective pesticide.
One that, while killing the pest individuals, spares much or most of the other fauna or flora, including beneficial species, either through differential toxic action or through the manner in which the pesticide is used (formulation, dosage, timing, placement, etc.).
Senescence.
Process or state of growing old.
Sex lure.
Synthetic chemical that acts as the natural lure (pheromone) for one sex of an insect species.
Signal word.
A required word that appears on every pesticide label to denote the relative toxicity of the product. The signal words are either Danger-Poison for highly toxic compounds, Warning for moderately toxic, or Caution for slightly toxic.
Slimicide.
Chemical used to prevent slimy growth, as in wood-pulping processes for manufacture of paper and paperboard.
Slurry.
Thin, watery mixture, such as liquid mud, cement, etc. Fungicides and some insecticides are applied to seeds as slurries to produce thick coating and reduce dustiness.
Soil application.
Application of pesticide made primarily to soil surface rather than to vegetation.
Soil persistence.
Length of time that a pesticide application on or in soil remains effective.
Soluble powder.
A finely ground, solid material that will dissolve in water or some other liquid carrier.
Spot treatment.
Application to localized or restricted areas, as differentiated from overall, broadcast, or complete coverage.
Spreader.
Ingredient added to spray mixture to improve contact between pesticide and plant surface.
Sticker.
Ingredient added to spray or dust to improve its adherence to plants.
Stomach poison.
A pesticide that must be eaten by an insect or other animal in order to kill or control the animal.
Structural pests.
Pests that attack and destroy buildings and other structures, clothing, stored food, and manufactured and processed goods; for example, termites, cockroaches, clothes moths, rats, and dry-rot fungi.
Stupefacient or soporific.
Drug used as a pesticide to cause birds to enter a state of stupor so they can be captured and removed, or to frighten other birds away from the area.
Subcutaneous toxicity.
The toxicity determined following its injection just below the skin.
Surfactant.
Ingredient that aids or enhances the surface-modifying properties of a pesticide formulation (wetting agent, emulsifier, or spreader).
Suspension.
Finely divided solid particles dispersed in a liquid.
Synergism.
Increased activity resulting from the effect of one chemical on another.
Synthesize.
Production of a compound by joining various elements or simpler compounds.
Systemic.
Compound that is absorbed and translocated throughout the plant or animal.


T.
Tank mix.
Mixture of two or more pesticides in the spray tank at time of application. Such mixture must be cleared by EPA.
Target.
The plants, animals, structures, areas, or pests to be treated with a pesticide application.
Temporary tolerance.
A tolerance established on an agricultural commodity by EPA to permit a pesticide manufacturer or his agent time, usually one year, to collect additional residue data to support a petition for a permanent tolerance; in essence, an experimental tolerance. (See Tolerance.)
Teratogenic.
Substance that causes physical birth defects in the offspring following exposure of the pregnant female.
Tolerance.
Amount of pesticide residue permitted by federal regulation to remain on or in a crop. Expressed as parts per million (ppm).
Tolerant.
Capable of withstanding effects.
Topical application.
Treatment of a localized surface site such as a single leaf blade, on an insect, etc., as opposed to oral application.
Toxic.
Poisonous to living organisms.
Toxicant.
A poisonous substance such as the active ingredient in pesticide formulations that can injure or kill plants, animals, or microorganisms.
Toxin.
A naturally occurring poison produced by plants, animals, or microorganisms; for example, the poison produced by the black widow spider, the venom produced by snakes, and the botulism toxin.
Trade name (trademark name, proprietary name, brand name).
Name given a product by its manufacturer or formulator, distinguishing it as being produced or sold exclusively by that company.
Translocation.
Transfer of food or other materials such as herbicides from one plant part to another.
Trivial name.
Name in general or commonplace usage; for example, nicotine.


U.
Ultralow volume (ULV).
Sprays that are applied at 0.5 gallon or less per acre or sprays applied as the undiluted formulation.


V.
Vector.
An organism, as an insect, that transmits pathogens to plants or animals.
Virustatic.
Prevents the multiplication of a virus.
Volatilize.
To vaporize.


W.
Weed.
Plant growing where it is not desired.
Wettable powder.
Pesticide formulation of toxicant mixed with inert dust and a wetting agent that mixes readily with water and forms a short-term suspension (requires tank agitation).
Wetting agent.
Compound that causes spray solutions to contact plant surfaces more thoroughly.
Winter annual.
Plant that starts germination in the fall, lives over winter, and completes its growth, including seed production, the following season.


Other Terms Relating To Toxic Substances

 
ACGIH
Abbreviation for the American Conference of Governmental Industrial Hygienists, a private organization of occupational safety and health professionals. The ACHIG recommends occupational exposure limits for numerous toxic substances, and it updates and revises its recommendations as more information becomes available. ACHIG limits are not legally enforceable. See OCCUPATIONAL EXPOSURE LIMITS.
Carcinogenic
Capable of causing cancer.
Ceiling Limit
The maximum amount of a toxic substance allowed to be in workroom air at any time during the day.
Combustible
Able to catch on fire and burn.
Concentration
The amount of one substance in another substance.
Decomposition
Breakdown of a chemical.
Density
How much space a given weight of substance takes up. Gold is a very dense substance because a small amount of it weighs a lot. Styrofoam is not very dense because it weighs very little but takes up a lot of space. The density of a substance is usually compared to water, which has a density of 1. Substances more dense than water (which sink in water) have densities greater than 1; substances which float on water have densities less than 1.
Dermal
By or through the skin.
Explosive Limits
The amounts of vapor in air which form explosive mixtures. Explosive limits are expressed as LOWER EXPLOSIVE LIMITS and UPPER EXPLOSIVE LIMITS; these give the range of vapor concentrations in air which will explode if heat is added. Explosive limits are expressed as percent of vapor in air.
Flammable
Catches on fire easily and burns rapidly.
Flammable Limits
See EXPLOSIVE LIMITS.
Flash Point
The lowest temperature at which the vapor of a substance will catch on fire, and then go out, if heat is applied. Provides an indication of how flammable a substance is. Not to be confused with IGNITION TEMPERATURE.
Gram
The unit of mass in the metric system. An ounce is about 28 grams, and a pound is approximately 450 grams. (A teaspoon of sugar weights about 8 grams.)
Health Hazard
Anything which can have a harmful effect on health under the conditions in which it is used or produced. There can be both ACUTE and CHRONIC health hazards.
Ignition Temperature
The lowest temperature at which a substance will catch on fire and continue to burn. The lower the ignition temperature, the more likely the substance is going to be a fire hazard.
Inflammable
Same as FLAMMABLE.
Ingestion
Swallowing.
Kilogram
1000 grams. One kilogram equals about 2.2 pounds.
LC50
The concentration of a substance in air that causes death in 50% of the animals exposed by inhalation. A measure of acute toxicity.
LD50
The dose that causes death in 50% of the animals exposed by swallowing a substance. A measure of acute toxicity.
Liter
The unit of volume in the metric system. A liter is about the same as a quart.
Meter
The unit of length in the metric system. A meter is about 40 inches.
mg/kg
A way of expressing dose: milligrams (mg) of a substance per kilogram (kg) of body weight. Example: a 100 kg (220 pound) person given 10,000 mg (about 0.02 pounds) of a substance would be getting a dose of 100 mg/kg (10,000 mg/100 kg).
mg/m3
A way of expressing the concentration of a substance in air: milligrams (mg) of substance per cubic meter (m3) of air.
Milligram
One one-thousandth of a gram.
Mutagenic
Capable of changing cells in such a way that future cell generations are affected. Mutagenic substances are usually considered suspect carcinogens.
NIOSH
Abbreviation for the National Institute for Occupational Safety and Health, U.S. Department of Health and Human Services. NIOSH does research on occupational safety and health questions and makes recommendations to OSHA.
Occupational Exposure Limits
Maximum allowable concentrations of toxic substances in workroom air to protect workers who are exposed to toxic substances over a working lifetime.
Odor Threshold
The lowest concentration of a substance's vapor, in air, that can be smelled. Odor thresholds are highly variable depending on the individual who breathes the substance and the nature of the substance.
OSHA
Abbreviation for the Occupational Safety and Health Administration, U.S. Department of Labor. OSHA develops and enforces federal standards for occupational safety and health.
Oxidizer
Any substance which reacts violently with oxygen or which gives off large amounts of energy in a chemical reaction.
pH
A measure of how acid or how caustic (basic) a substance is on a scale of 1-14. pH 1 indicates that a substance is very acid; pH 7 indicates that a substance is neutral; and pH 14 indicates that a substance is very caustic (basic).
Polymerization
A chemical reaction in which individual molecules combine to form a single large chemicl molecule (a polymer). Usually involves the release of a lot of energy.
PPM
Parts per million. Generally used to express small concentrations of one substance in a mixture.
Reactivity
The ability of a substance to undergo change, usually by combining with another substance or by breaking down. Certain conditions, such as heat and light, may cause a substance to become more reactive. Highly reactive substances may explode.
Solubility
The amount of a substance that can be dissolved in a solvent, usually water.
Solvent
Usually, a liquid in which other substances are dissolved. The most common solvent is water.
Suspect Carcinogen
A substance that might cause cancer in humans or animals but has not been proven to do so.
Teratogenic
Capable of causing birth defects.
Thermal
Involving heat.
TLV
Abbreviation for Threshold Limit Value. The average 8-hour occupational exposure limit. This means that the actual exposure level may sometimes be higher, sometimes lower, but the average must not exceed the TLV. TLVs are calculated to be safe exposures for a working lifetime.
Toxic Substance
Any substance which can cause acute or chronic injury to the human body, or which is suspected of being able to cause disease or injury under some conditions. Many toxic substances are chemicals or chemical mixtures, but there are other kinds of toxic substances as well (bacteria and viruses, for example).
Vapor
The gas given off by a solid or liquid substance at ordinary temperatures.
Vapor Density
The density of the gas given off by a substance. It is usually compared with air, which has a vapor density set at 1. If the vapor is more dense than air (greater than 1), it will sink to the ground; if it is less dense than air (less than 1), it will rise.
Viscosity
A relative measure of how slowly a substance pours or flows. Very viscous substances, like molasses, pour very slowly. Slightly viscous substances, like water, pour and splash easily .
Volatility
A measure of how quickly a substance forms vapor at ordinary temperatures.