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 pollution control device that forces dirty air through a tower packed with crushed rock or wood chips while liquid is sprayed over the packing material. The pollutants in the air stream either dissolve or chemically react with the liquid.
the fill in a confined space in a stripping vessel, ranging from simply shaped units such as rocks or slats to complex shapes that provide large surface area per unit volume.
Performance Audit Inspection.
Preliminary Assessment Information Rule.
Point, Area and Line Source Air Quality Model.
PAL Model with Deposition and Settling of Pollutants.
irregular, rapid heartbeat.
(Peroxyacetyl nitrate) a pollutant created by the action of sunlight on hydrocarbons and nitrogen oxides in the air. An ingredient of smog.
widespread throughout an area, nation or the world.
Powered Air-Purifying Respirator.
Protective Action Recommendation
Precision and Accuracy Reporting System.
a characteristic element or constant factor.
a standard herbicide used to kill various types of crops, including marijuana.
a sensation of prickling, tingling, or creeping on the skin that has no objective cause.
the first part of the two part application that must be submitted by a TSD facility to receive a permit. It contains general facility information. There is a standard form for the Part A.
the second part of the permit application that includes detailed and highly technical information concerning the TSD in question. There is no standard form for the Part B, instead the facility must submit information based on the regulatory requirements.
the closure of a discrete part of a facility in accordance with the applicable closure requirements of 40 CFR Parts 264 or 265. For example, partial closure may include the closure of a trench, a unit operation, a land-fill cell, or a pit, while other parts of the same facility continue in operation or will be placed in operation in the future. A proposed redefinition was published in the March 19, 1985, Federal Register (50 CFR 11068).
small, separate pieces of an airborne material.Dusts, fumes, smokes, mists, and fogs are examples. Generally, anything that is not a fiber and has an aspect ratio of 3 to 1.
the mass of particulates per unit volume of air or water.
fine liquid or solid particles such as dust, smoke, mist, fumes, or smog, found in the air or emissions.
the introduction of particulates into ambient air.
see Coefficient of Water/Oil Distribution.
parts per million
this is a weight per volume measurement used in water and wastewater analysis. It is interchangeable with "milligrams per liter". Chemical dosages are often referred to as parts per million, i.e. 100 ppm of polymer.100 ppm = 0.1%.
Preliminary Assessment/Site Inspection.
Procurement Automated Source System.
a process for killing pathogenic organisms by heat applied for a critical period of time.
Permit Assistance Team.
capable of causing disease.
microorganisms that can cause disease in other organisms or in humans, animals and plants. They may be bacteria, viruses, or parasites and are found in sewage, in runoff from animal farms or rural areas populated with domestic and/or wild animals, and in water used for swimming. Fish and shellfish contaminated by pathogens, or the contaminated water itself, can cause serious illnesses.
polychlorinated biphenyl; a pathogenic and teratogenic industrial compound used as a heat-transfer agent; PCBs may accumulate in human or animal tissue.
Personnel Compensation and Benefits.
Permit Compliance System.
Positive Crankcase Ventilation.
Preconstruction Direct Flame Ionization Detection.
Pesticide Document Management System.
Pretty Damn Quick.
Particulate Data Reduction.
Personnel Decontamination Station.
Preliminary Endangerment Assessment.
permissible exposure limits; specific exposure limits established by OSHA for 600 industrial chemicals. This may be expressed as a time-weighted average (TWA) limit or as a ceiling exposure limit that legally must never be exceeded instantaneously even if the TWA exposure limit is not violated. OSHA PELs have the force of law. Note that ACGIH TLVs and NIOSH RELs are recommended exposure limits that may or may not be enacted into law by OSHA.
Personal Exposure Limit.
Partial Equilibrium Multimarket Model.
Personal Exposure Model.
Professional Environmental Marketing Association.
Pensky-Martens Closed Cup or Closed Tester
Prolonged Elevated Pollution Episode.
percent volatile by volume. The percentage of a liquid or solid (by volume) that evaporates at an ambient temperature of 70 degrees F (20 degrees C) unless some other temperature is stated. E.g., gasoline and paint thinner (mineral spirits) are 100% volatile; their individual evaporation rates vary, but over a period of time each evaporates completely. This physical characteristics reflects the potential for releasing harmful vapor into the air.
downward flow or filtering of water through pores or spaces in rock or soil.
an arrangement of the elements in order of increasing atomic number that illustrates the repetition (or periodicity) of key characteristics.
Functional disturbances and/or pathological changes in the nervesin the extremities (hands, feet, arms and legs).
the ability of a body to pass a fluid under pressure.
describes water that has passed through a reverse osmosis membrane.
an authorization, license, or equivalent control document issued by EPA or an authorized State to implement the regulatory requirements of Subtitle C Parts 264 and 265 for TSDs.
a provision of Subtitle C whereby a facility is deemed to have a RCRA permit if it is permitted under the Safe Drinking Water Act, the Clean Water Act, or the Marine Protection, Research, and Sanctuaries Act and also meets a few additional Subtitle C requirements as specified at 40 CFR Section 270.60.
refers to the length of time a compound, once introduced into the environment, stays there. A compound may persist for less than a second or indefinitely.
pesticides that do not break down chemically and remain in the environment after a growing season.
an individual, trust, firm, joint stock company, corporation (including a government corporation), partnership, association, State, municipality, commission, political subdivision of a State, or any interstate body. Person also includes a consortium, a joint venture, a commercial entity, and the United States Government.
precautionary measures taken to maintain good health when exposed to potentially harmful materials. This includes keeping hands, other parts of the body, work clothing, and equipment free of a material's residue, as well as not eating, drinking, applying makeup, or using toilet facilities where it is in use.
The act of protecting the body against contact with known or anticipated chemical hazards. Equipment for this purpose includes respirators, gloves, safety glasses, chemical resistant clothing, etc. 
personal protective equipment
an insect, rodent, nematode, fungus, weed or other form of terrestrial or aquatic plant or animal life or virus, bacterial or microorganism that is injurious to health or the environment.
Pesticides Analytical Transport Solution.
any substance used to control pests ranging from rats, weeds, and insects to algae and fungi. Pesticides can accumulate in the food chain and can contaminate the environment if misused.
the amount of pesticide residue allowed by law to remain in or on a harvested crop. By using various safety factors, EPA sets these levels well below the point where the chemicals might be harmful to consumers.
petroleum UST system
means an underground storage tank system that contains petroleum or a mixture of petroleum with de minimis quantities of other regulated substances. Such systems include those containing motor fuels, jet fuels, distillate fuel oils, residual fuel oils, lubricants, petroleum solvents, and used oils.
Perfluorocarbons (zero ozone depletion potential).
a unit for measuring hydrogen ion concentrations. A pH of 7 indicates a "neutral" water or solution. At pH lower than 7, a solution is acidic. At pH higher than 7, a solution is alkaline.
Principal Hazardous Constituent.
Public Health Evaluation.
organic compounds that are byproducts of petroleum refining, tanning, textile, dye, and resin manufacture. Low concentrations can cause taste and odor problems in water, higher concentrations can kill aquatic life.
hormonal chemical produced by female of a species to attract a mate.
thick mucous from the respiratory passage.
salts or esters of phosphoric acid.
an essential food element that can contribute to the eutrophication of water bodies.
air pollutants formed by the action of sunlight on oxides of nitrogen and hydrocarbons.
air pollution caused by not one pollutant but by chemical reactions of various pollutants emitted from different sources.
intolerance to light.
the manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll, using sunlight as an energy source.
something that harms plants.
Public Health Service Act.
physical and chemical treatment
processes generally used in large-scale waste-water treatment facilities. Physical processes may involve air-stripping or filtration. Chemical treatment includes coagulation, chlorination, or ozone addition. The term can also refer to treatment processes, treatment of toxic materials in surface waters and ground waters, oil spills, and some methods of dealing with hazardous materials on or in the ground.
a substance for which there is valid evidence that it is a combustible liquid, compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable (reactive), or water reactive.
the condition of a material; i.e., solid, liquid, or gas, at room temperature.
that portion of the plankton community comprised of tiny plants, e.g., algae, diatoms.
something that harms plants.
Public Information Assist Team.
acid used in treating steel for removal of oxide scale.
measurement of radioactivity. A picocurie is one million millionth, or a trillionth, of a curie, and represents about 2.2 radioactive particle disintegrations per minute.
picocuries per liter (pCi/L)
a unit of measure used for expressing levels of radon gas. (See: picocurie).
a container, usually lead, used to ship or store radioactive materials.
Pesticides in Groundwater Strategy.
(1) the fuel element in a nuclear reactor. (2) a heap of waste.
Product Identification Number.A four-digit number, prefaced by UN or NA, used in Canada under the Transportation of Dangerous Goods Regulation for use by emergency personnel to identify a material in the event of an accident.
Procurement Information Notice.
Public Information Officer
Public Involvement Program.
means a hollow cylinder or tubular conduit that is constructed of non-earthen materials.
pipeline facilities (including gathering lines)
are new and existing pipe rights-of-way and any associated equipment, facilities, or buildings.
Public Interest Research Group.
Pretreatment Implementation Review Task Force.
small organisms with limited powers of locomotion, carried by water currents from place to place.
a circular piece of DNA that exists apart from the chromosome and replicates independently of it. Bacterial plasmids carry information that renders the bacterial resistant to antibiotics. Plasmids are often used in genetic engineering to carry desired genes into organisms.
non-metallic compounds that result from a chemical reaction, and are molded or formed into rigid or pliable structural material.
refers to exercise participants who have assignments as members of an emergency response organization or team that will be committed to execute or support specific Federal, State or local efforts. These assignments can include saving lives, protecting property and public health, obtaining and managing resources, and maintaining public safety upon the occurrence of an oil or hazardous material spill or release. Players will make decisions and respond to scenario events in as realistic a manner as possible. All players should be familiar with the emergency response structure, functions, and procedures that they will be expected to perform.
Pollution Liability Insurance and Risk Retention Act.
Polarized Light Microscopy.
(1) the act or process of stopping the flow of water, oil, or gas into or out of a formation through a borehole or well penetrating that formation. (2) Stopping a leak or sealing off a pipe or hose.
(1) a visible or measurable discharge of a contaminant from a given point of origin. Can be visible or thermal in water, or visible in the air as, for example, a plume of smoke. (2) The area of measurable and potentially harmful radiation leaking from a damaged reactor. (3) The distance from a toxic release considered dangerous for those exposed to the leaking fumes.
a radioactive metallic element similar chemically to uranium.
particulate matter; air emissions regulated under Titles 1 and III of the CAA Amendments.
Pensky-Martens closed cup. One of several types of apparatus for determining flash points. The Pensky-Martens closed tester (ASTM D93-79) is used for liquids that have a viscosity of 45 SUS (Saybolt universal seconds) or more at 100 degrees F (38 degrees C), a flash point of 200 degrees F (93.6 degrees C) or higher, contain suspended solids, or form surface films.
Premanufacture Notification Form.
Pollutant Mass Rate.
Polynuclear Aromatic Hydrocarbons.
Word element pertaining to lung, air or gas.
a respiratory tract and lung condition caused by inhalation and retention of irritant mineral or metallic particles.An X ray can detect changes, which include fibrosis, emphysema.
inflammatory lung disease caused by microorganisms, virus, and chemical or physical irritants.
peripheral nervous system effects.
Point of Compliance.
Program Office Contracts.
Principal Organic Hazardous Constituents.
point of disinfectant application
is the point where the disinfectant is applied and water downstream of that point is not subject to recontamination by surface water runoff.
any discernible, confined, and discrete conveyance, including, but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include return flows from irrigated agriculture.
Poison, Class A
a DOT term for an extremely dangerous poison such as a poisonous gas or liquid of such a nature that a very small amount of the gas or vapor of the liquid mixed with air is dangerous to life. E.g., phosgene, cyanogen, hydrocyanic acid, and nitrogen peroxide.
Class B poisons are those substances, liquid or solid (including pastes and semisolids), other than Class A poisons or Irritating materials, which are known to be so toxic to man as to afford a hazard to health during transportation; or which, in the absence of adequate data on human toxicity, are presumed to be toxic to man because they fall within any one of the following categories when tested on laboratory animals:(1) Oral toxicity. Those which produce death within 48 hours in half or mare than half of a group of 10 or mare white laboratory rats weighing 200 to 300 grams at a single dose of 50 milligrams or less per kilogram of body weight, when administered orally.(2) Toxicity on inhalation. Those which produce death within 48 hours in half or more than half of a group of 10 or more white laboratory rats weighing 200 to 300 grams, when inhaled continuously for a period of one hour or less at a concentration of 2 milligrams or less per liter of vapor, mist, or dust, provided such concentration is likely to be encountered by man when the chemical product is used in any reasonable foreseeable manner.(3) Toxicity by skin absorption. Those which produce death within 48 hours in half or more than half of a group of 10 or more rabbits tested at a dosage of 200 milligrams or less per kilogram body weight, when administered by continuous contact with the bare skin for 24 hours or less.The foregoing categories shall not apply if the physical characteristics or the probable hazards in humans as shown by experience indicate that the substances will not cause serious sickness or death.
Poison Control Center
provides medical information on a 24-hour basis for accidents involving ingestion of potentially poisonous materials. Call your area's largest hospital to find the one nearest to you.
A liquid having a saturated vapor concentration at 20 ¿C (68 ¿F) equal to or greater than ten times its LC5O (vapor) value if the LC5O value is 100 parts per million (ppm) or less. LC5O for this definition is the concentration of vapor that, when administered by continuous inhalation of both male and female young albino rats for one hour, is most likely to cause death within 14 days to one half of the animals tested.The result is expressed in milliliters per cubic meter of air (ppm).If LC50 data are available based on other than a one hour exposure, a factor may be used to determine an acceptable one hour value for the purposes of this section. If the only value available is for a 4 hours exposure, that value is multiplied by 2. This method of estimating a LC5O value may not be used when a material causes death by direct pulmonary effect, i.e., by destruction of lung tissue as opposed to systemic poisoning. For these corrosive poisons, the exposure period must be one hour.
Petroleum, Oils, and Lubricants.
in corrosion, to develop a barrier on the anodic or cathodic surface, disrupting the corrosion process.
a document that specifies operating policies that must be followed. They are used by program offices to outline the manner in which pieces of the RCRA program are to be carried out.
a fine dust produced by plants; the fertilizing element of flowering plants; a natural or background air pollutant.
a contaminant at a concentration high enough to endanger the aquatic environment or the public health.Pollutant or contaminant as defined by section 101(33) of CERCLA, shall include, but not be limited to, any element, substance, compound, or mixture, including disease-causing agents, which after release into the environment and upon exposure, ingestion, inhalation, or assimilation into any organism, either directly from the environment or indirectly by ingestion through food chains, will or may reasonably be anticipated to cause death, disease, behavioral abnormalities, cancer, genetic mutation, physiological malfunctions (including malfunctions in reproduction) or physical deformations, in such organisms or their offspring. The term does not include petroleum, including crude oil or any fraction thereof which is not otherwise specifically listed or designated as a hazardous substance under section 101(14) (A) through (F) of CERCLA, nor does it include natural gas, liquefied natural gas, or synthetic gas of pipeline quality (or mixtures of natural gas and such synthetic gas). For purposes of the NCP, the term pollutant or contaminant means any pollutant or contaminant that may present an imminent and substantial danger to public health or welfare.
those constituents of wastewater determined to be detrimental and, therefore, requiring control.
Pollutant Standard Index (PSI)
measure of adverse health effects of air pollution levels in major cities.
generally, the presence of matter or energy whose nature, location, or quantity produces undesired environmental effects. Under the Clean Water Act, for example, the term is defined as the man-made or man-induced alteration of the physical, biological, and radiological integrity of water.
synthetic chemicals that help solids to clump during sewage treatment.
a polymetric material having ion exchange sites on its skeleton.
see Monomer. A chain or organic molecules produced by the joining of primary units called monomers.
a chemical reaction in which one or more small molecules combine to form larger molecules. A hazardous polymerization is such a reaction that takes place at a rate that releases large amounts of energy that can cause fires or explosions or burst containers. Materials that can polymerize usually contain inhibitors that can delay the reactions.
molecularly dehydrated orthophosphate.
a general term for Thio-Red, a patented precipitating reagent. An organic sulfur polymer with the general formula: CS3.
a plastic that releases hydrochloric acid when burned.
Particulate Organic Matter.
Polycyclic Organic Matter.
a group of interbreeding organisms of the same kind occupying a particular space. Genetically, the number of humans or other living creatures in a designated area.
the degree of openness of a spongelike quality in a resin structure.
analytical results for which measurable concentration (i.e., above a quantitation limit) are reported.May have data qualifiers attached.
the time period following the shutdown of a waste management or manufacturing facility. For monitoring purposes, this is often considered to be 30 years.
refers to the phase of response actions, during which actions are taken after the release or the potential for a release has ceased.
post-removal site control
means those activities that are necessary to sustain the integrity of a Fund-financed removal action following its conclusion. Post-removal site control may be a removal or remedial action under CERCLA. The term includes, without being limited to, activities such as relighting gas flares, replacing filters, and collecting leachate.
Potable Water Treatment (ETUS).
appetizing water that is safe for drinking and use in cooking. Water which is suitable for human consumption.
Potential Emergency Condition
refers to "an incident or threat of a release which can be controlled by the first response agencies and does not require evacuation of other than the involved structure or immediate outdoor area. The incident is confined to a small area and does not pose an immediate threat to life or property."
Potentially Responsible Party (PRP)
any individual or company -- including owners, operators, transporters or generators -- potentially responsible for, or contributing to, the contamination problems at a Superfund site. Whenever possible, EPA requires PRP's, through administrative and legal actions, to clean up hazardous waste sites they have contaminated.
publicly owned treatment works; state or local government owned waste treatment facilities.
the temperature at which a liquid either congeals or flows.
a volcanic ash, first found at Pozzuoli, Italy, and used as an ingredient in some cements and mortars.
Pesticide Producers Association.
Pollution Prevention Act (1990); federal law establishing a national policy of pollution prevention and waste reduction.
parts per billion.
Personal Protective Clothing.
Catalyzed Zinc/Lead Precipitant - Chelator Breaker - Heavy Metal (ETUS).
personal protective equipment; safety gear, including chemical protective clothing and breathing apparatus.
Pesticide Product Information System.
parts per million; a way of expressing tiny concentrations.In air ppm is usually a volume/volume ratio; in water, a weight/volume ratio.
Poison Prevention Packaging Act.
Parts per Quadrillion.
parts per trillion.
Parts per Thousand.
Practical Quantitation Limit.
Paperwork Reduction Act.
Planned Regulatory Action.
discrete particles of material rejected from a liquid solution.
removal of solids from liquid waste so that the hazardous solid portion can be disposed of safely; removal of particles from airborne emissions.
air pollution control devices that collect particles from an emission by mechanical or electrical means.
in front of the heart, stomach.
in photochemical terminology, a compound such as a volatile organic compound (VOC) that "precedes" an oxidant.Precursors react in sunlight to form ozone or other photo- chemical oxidants.
(PA) means review of existing information and an off-site reconnaissance, if appropriate, to determine if a release may require additional investigation or action. A PA may include an on-site reconnaissance, if appropriate.
a loss in pressure due to flow restrictions or friction.
process of solid/liquid phase separation effected by passing the more permeable liquid phase through a mesh which is impenetrable to the solid phase.
A chemical that falls within any of the following categories:(1) A chemical that generates pressure by spontaneous polymerization unless protected by the addition of an inhibitor, by refrigeration, or by other thermal control.(2) A chemical that may decompose to release gas in its container.(3) A chemical that pressurizes the contents of a self-pressurized container.
a system of pipes in which water, wastewater, or other liquid is transported to a higher elevation by use of pumping force.
processes used to reduce the amount of pollution in water before it enters the sewers or the treatment plant.
measures taken to minimize the release of wastes to the environment.
prevention of significant deterioration (PSD)
EPA program in which state and/or federal permits are required that are intended to restrict emissions for new or modified sources in places where air quality is already better than required to meet primary and secondary ambient air quality standards.
primary drinking water regulation
applies to public water systems and specifies a contaminant level, which, in the judgment of the EPA Administrator, will have no adverse effect on human health.
first treatment for the removal of settleable solids from wastewater which is passed through a treatment works.
the first stage of waste water treatment; removal of floating debris and solids by screening and sedimentation.
primary waste treatment
first steps in wastewater treatment; screens and sedimentation tanks are used to remove most material that floats or will settle. Primary treatment results in the removal of about 30 percent of carbonaceous biochemical oxygen demand from domestic sewage.
Prevention Reference Manuals.
any water which, during manufacturing or processing, comes into direct contact with or results from the production or use of any raw material, intermediate product, finished product, by-product or waste product.
water prior to its direct contact use in a process or operation. This water may be any combination of raw water, service water, or either process wastewater or treatment facility effluent to be recycled or reused.
the total weight of all materials, including fuel, used in a manufacturing process. It is used to calculate the allowable rate of emission of pollutant matter from the process.
product identification number
The trade name of the manufacturer; some commodity chemicals are sold by their common name.
physical exhaustion, incapacitation.
complex nitrogenous organic compounds of high molecular weight that contain amino acids as their basic unit and are essential for growth and repair of animal tissue. Many proteins are enzymes.
presence of protein in the urine.
a membrane bound cell from which the outer cell has been partially or completely removed. The term often is applied to plant cells.
large microscopic single-cell organisms higher on the food chain than bacteria which consume bacteria.
Potentially responsible party; individual or organization legally liable under CERCLA for cleanup of NPL sites.
Pipeline Safety Act.
Preliminary Site Assessment.
Point Source Ambient Monitoring.
Prevention of Significant Deterioration.
Pretreatment Standards for Existing Sources.
Pollutant Standards Index.
Pounds per Square Inch.
Pressure per Square Inch.
pounds per square inch absolute.
Pressure per Square Inch Gauge.
Pretreatment Standards for New Sources.
PSY. acting on the mind.
Point Source Gaussian Diffusion Model.
Public Information Officer
refers to a designated point of contact responsible for interface with the media or other appropriate agencies requiring information concerning the incident/accident.
as defined by section 311(a)(4) of the CWA, means a vessel owned or bareboat-chartered and operated by the United States, or by a state or political subdivision thereof, or by a foreign nation, except when such vessel is engaged in commerce.
public water system
a system that has 15 or more service connections or that regularly serves at least 25 people a day for at least 60 days each year. Public water systems are divided into two categories: community water systems and noncommunity water systems.
publicly owned treatment works
a waste-treatment works owned by a state, unit of local government, or Indian tribe, usually designed to treat domestic wastewaters. Also known as POTW's.
pulmonary systems effects. Effects on respiration and respiratory pathology.
fluid in the lungs.
the crushing or grinding of materials into small pieces.
a machine installed on sewers to pull the sewage uphill. In most sewer systems waste water flows by gravity to the treatment plant.
to clean, clear, or empty of material.
a substance that can rot quickly enough to cause odors and attract flies.
Public Water Supply.
Public Water System.
Ports and Waterways Safety Act.
Public Water Supply System.
Transformation of a compound into one or more other substances by heat alone, i.e., without oxidation. Though the term implies decomposition into smaller fragments, pyrolytic change may also involve isomerization and formation of higher molecular weight compounds.
describes materials that ignite spontaneously in air below 130 degrees F (54 degrees C). Occasionally friction ignites them.