Laboratory Terms P

A glossary of science, chemistry, environmental and laboratory terms.

Analytical testing dots



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 |



163 results match your search term:  P


Packaging
The assembly of one or more containers and any other components necessary to ...

Find the meaning of the term: Packaging...


Packed Bed Scrubber
An air pollution control device in which emissions pass through alkaline wate...

Find the meaning of the term: Packed Bed Scrubber...


Packed Tower
A pollution control device that forces dirty air through a tower packed with ...

Find the meaning of the term: Packed Tower...


Packer
An inflatable gland, or balloon, used to create a temporary seal in a borehol...

Find the meaning of the term: Packer...


Palatable Water
Water, at a desirable temperature, that is free from objectionable tastes, od...

Find the meaning of the term: Palatable Water...


Pandemic
A widespread epidemic throughout an area, nation or the world.

Find the meaning of the term: Pandemic...


Paper
In the recycling business, refers to products and materials, including newspa...

Find the meaning of the term: Paper...


Paper Processor
Intermediate facility where recovered paper or plastic products and materials...

Find the meaning of the term: Paper Processor...


Parameter
A variable, measurable property whose value is a determinant of the character...

Find the meaning of the term: Parameter...


Paraquat
A standard herbicide used to kill various types of crops, including marijuana...

Find the meaning of the term: Paraquat...


Parshall Flume
Device used to measure the flow of water in an open channel.

Find the meaning of the term: Parshall Flume...


Participation Rate
Portion of population participating in a recycling program.

Find the meaning of the term: Participation Rate...


Particle Count
Results of a microscopic examination of treated water with a special "particl...

Find the meaning of the term: Particle Count...


Particulate Loading
The mass of particulates per unit volume of air or water.

Find the meaning of the term: Particulate Loading...


Particulates
1. Fine liquid or solid particles such as dust, smoke, mist, fumes, or smog, ...

Find the meaning of the term: Particulates...


Partition Coefficient
Measure of the sorption phenomenon, whereby a pesticide is divided between th...

Find the meaning of the term: Partition Coefficient...


Parts Per Billion ppb
Units commonly used to express contamination ratios, as in establishing the m...

Find the meaning of the term: Parts Per Billion ppb...


Passive Smoking
Inhalation of others' tobacco smoke.

Find the meaning of the term: Passive Smoking...


Passive Treatment Walls
Technology in which a chemical reaction takes place when contaminated ground ...

Find the meaning of the term: Passive Treatment Walls...


Pathogens
Microorganisms (e.g., bacteria, viruses, or parasites) that can cause disease...

Find the meaning of the term: Pathogens...


Pathway
The physical course a chemical or pollutant takes from its source to the expo...

Find the meaning of the term: Pathway...


Pay-As-You-Throw
Systems under which residents pay for municipal waste management and disposal...

Find the meaning of the term: Pay-As-You-Throw...


PCB Congeners
Chlorine-substituted biphenyl compounds. PCB stands for polychlorinated biphe...

Find the meaning of the term: PCB Congeners...


Peak Electricity Demand
The maximum electricity used to meet the cooling load of a building or buildi...

Find the meaning of the term: Peak Electricity Demand...


Peak Levels
Levels of airborne pollutant contaminants much higher than average or occurri...

Find the meaning of the term: Peak Levels...


Percent Saturation
The amount of a substance that is dissolved in a solution compared to the amo...

Find the meaning of the term: Percent Saturation...


Perched Water
Zone of unpressurized water held above the water table by impermeable rock or...

Find the meaning of the term: Perched Water...


Perchlorates
Perchlorates are the salts derived from perchloric acid (HClO4). They occur b...

Find the meaning of the term: Perchlorates...


Percolating Water
Water that passes through rocks or soil under the force of gravity.

Find the meaning of the term: Percolating Water...


Percolation
1. The movement of water downward and radially through subsurface soil layers...

Find the meaning of the term: Percolation...


Performance Bond
Cash or securities deposited before a landfill operating permit is issued, wh...

Find the meaning of the term: Performance Bond...


Performance Data
Information collected, during a trial burn, on concentrations of designated o...

Find the meaning of the term: Performance Data...


Performance Standards
1. Regulatory requirements limiting the concentrations of designated organic ...

Find the meaning of the term: Performance Standards...


Periphyton
Microscopic underwater plants and animals that are firmly attached to solid s...

Find the meaning of the term: Periphyton...


Permeability
The rate at which liquids pass through soil or other materials in a specified...

Find the meaning of the term: Permeability...


Permissible Dose
The dose of a chemical that may be received by an individual without the expe...

Find the meaning of the term: Permissible Dose...


Permissible Exposure Limit
Also referred to as PEL, federal limits for workplace exposure to contaminant...

Find the meaning of the term: Permissible Exposure Limit...


Permit
An authorization, license, or equivalent control document issued by EPA or an...

Find the meaning of the term: Permit...


Persistence
Refers to the length of time a compound stays in the environment, once introd...

Find the meaning of the term: Persistence...


Persistent Pesticides
Pesticides that do not break down chemically or break down very slowly and re...

Find the meaning of the term: Persistent Pesticides...


Personal Air Samples
Air samples taken with a pump that is directly attached to the worker with th...

Find the meaning of the term: Personal Air Samples...


Personal Measurement
A measurement collected from an individual's immediate environment.

Find the meaning of the term: Personal Measurement...


Personal Protective Equipment
Clothing and equipment worn by pesticide mixers, loaders and applicators and ...

Find the meaning of the term: Personal Protective Equipment...


Pest
An insect, rodent, nematode, fungus, weed or other form of terrestrial or aqu...

Find the meaning of the term: Pest...


Pest Control Operator
Person or company that applies pesticides as a business (e.g. exterminator); ...

Find the meaning of the term: Pest Control Operator...


Pesticide
Substances or mixture there of intended for preventing, destroying, repelling...

Find the meaning of the term: Pesticide...


Pesticide Regulation Notice
Formal notice to pesticide registrants about important changes in regulatory ...

Find the meaning of the term: Pesticide Regulation Notice...


Pesticide Tolerance
The amount of pesticide residue allowed by law to remain in or on a harvested...

Find the meaning of the term: Pesticide Tolerance...


PETE
Polyethylene Terepthalate. Thermoplastic material used in plastic soft drink ...

Find the meaning of the term: PETE...


Petroleum
Crude oil or any fraction thereof that is liquid under normal conditions of t...

Find the meaning of the term: Petroleum...


Petroleum Derivatives
Chemicals formed when gasoline breaks down in contact with ground water.

Find the meaning of the term: Petroleum Derivatives...


pH
An expression of the intensity of the basic or acid condition of a liquid; ma...

Find the meaning of the term: pH...


Pharmacokinetics
The study of the way that drugs move through the body after they are swallowe...

Find the meaning of the term: Pharmacokinetics...


Phenolphthalein Alkalinity
The alkalinity in a water sample measured by the amount of standard acid need...

Find the meaning of the term: Phenolphthalein Alkalinity...


Phenols
Organic compounds that are byproducts of petroleum refining, tanning, and tex...

Find the meaning of the term: Phenols...


Phosphates
Certain chemical compounds containing phosphorus.

Find the meaning of the term: Phosphates...


Phosphogypsum Piles Stacks
Principal byproduct generated in production of phosphoric acid from phosphate...

Find the meaning of the term: Phosphogypsum Piles Stacks...


Phosphorus
An essential chemical food element that can contribute to the eutrophication ...

Find the meaning of the term: Phosphorus...


Phosphorus Plants
Facilities using electric furnaces to produce elemental phosphorous for comme...

Find the meaning of the term: Phosphorus Plants...


Photochemical Oxidants
Air pollutants formed by the action of sunlight on oxides of nitrogen and hyd...

Find the meaning of the term: Photochemical Oxidants...


Photochemical Smog
Air pollution caused by chemical reactions of various pollutants emitted from...

Find the meaning of the term: Photochemical Smog...


Photosynthesis
The manufacture by plants of carbohydrates and oxygen from carbon dioxide med...

Find the meaning of the term: Photosynthesis...


Physical and Chemical Treatment
Processes generally used in large-scale wastewater treatment facilities. Phys...

Find the meaning of the term: Physical and Chemical Treatment...


Phytoplankton
That portion of the plankton community comprised of tiny plants; e.g. algae, ...

Find the meaning of the term: Phytoplankton...


Phytoremediation
Low-cost remediation option for sites with widely dispersed contamination at ...

Find the meaning of the term: Phytoremediation...


Phytotoxic
Harmful to plants.

Find the meaning of the term: Phytotoxic...


Phytotreatment
The cultivation of specialized plants that absorb specific contaminants from ...

Find the meaning of the term: Phytotreatment...


Picocuries Per Liter
A unit of measure for levels of radon gas; becquerels per cubic meter is metr...

Find the meaning of the term: Picocuries Per Liter...


Piezometer
A nonpumping well, generally of small diameter, for measuring the elevation o...

Find the meaning of the term: Piezometer...


Pilot Tests
Testing a cleanup technology under actual site conditions to identify potenti...

Find the meaning of the term: Pilot Tests...


Plankton
Tiny plants and animals that live in water.

Find the meaning of the term: Plankton...


Plasma Arc Reactors
devices that use an electric arc to thermally decompose organic and inorganic...

Find the meaning of the term: Plasma Arc Reactors...


Plasmid
A circular piece of DNA that exists apart from the chromosome and replicates ...

Find the meaning of the term: Plasmid...


Plastics
Non-metallic chemoreactive compounds molded into rigid or pliable constructio...

Find the meaning of the term: Plastics...


Plate Tower Scrubber
An air pollution control device that neutralizes hydrogen chloride gas by bub...

Find the meaning of the term: Plate Tower Scrubber...


Plug Flow
Type of flow the occurs in tanks, basins, or reactors when a slug of water mo...

Find the meaning of the term: Plug Flow...


Plugging
Act or process of stopping the flow of water, oil, or gas into or out of a fo...

Find the meaning of the term: Plugging...


Plume
1. A visible or measurable discharge of a contaminant from a given point of o...

Find the meaning of the term: Plume...


Plutonium
A radioactive metallic element chemically similar to uranium.

Find the meaning of the term: Plutonium...


PM-10
PM 10 is measure of particles in the atmosphere with a diameter of less than ...

Find the meaning of the term: PM-10...


Pneumoconiosis
Health conditions characterized by permanent deposition of substantial amount...

Find the meaning of the term: Pneumoconiosis...


Point Source
A stationary location or fixed facility from which pollutants are discharged;...

Find the meaning of the term: Point Source...


Point-of-Contact Measurement of Exposure
Estimating exposure by measuring concentrations over time (while the exposure...

Find the meaning of the term: Point-of-Contact Measurement of Exposure...


Point-of-Disinfectant Application
The point where disinfectant is applied and water downstream of that point is...

Find the meaning of the term: Point-of-Disinfectant Application...


Point-of-Use Treatment Device
Treatment device applied to a single tap to reduce contaminants in the drinki...

Find the meaning of the term: Point-of-Use Treatment Device...


Pollen
The fertilizing element of flowering plants; background air pollutant.

Find the meaning of the term: Pollen...


Pollutant
Generally, any substance introduced into the environment that adversely affec...

Find the meaning of the term: Pollutant...


Pollutant Pathways
Avenues for distribution of pollutants. In most buildings, for example, HVAC ...

Find the meaning of the term: Pollutant Pathways...


Pollutant Standard Index PSI
Indicator of one or more pollutants that may be used to inform the public abo...

Find the meaning of the term: Pollutant Standard Index PSI...


Pollution
Generally, the presence of a substance in the environment that because of its...

Find the meaning of the term: Pollution...


Pollution Prevention
1. Identifying areas, processes, and activities which create excessive waste ...

Find the meaning of the term: Pollution Prevention...


Polonium
A radioactive element that occurs in pitchblende and other uranium-containing...

Find the meaning of the term: Polonium...


Polychlorinated Biphenyls
A group of toxic, persistent chemicals used in electrical transformers and ca...

Find the meaning of the term: Polychlorinated Biphenyls...


Polycyclic Aromatic Hydrocarbons PAH
Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds that consist o...

Find the meaning of the term: Polycyclic Aromatic Hydrocarbons PAH...


Polyelectrolytes
Synthetic chemicals that help solids to clump during sewage treatment.

Find the meaning of the term: Polyelectrolytes...


Polyethylene Diffusion Bags PDB
Polyethylene Diffusion Bags are bags used to collect water samples for labora...

Find the meaning of the term: Polyethylene Diffusion Bags PDB...


Polymer
A natural or synthetic chemical structure where two or more like molecules ar...

Find the meaning of the term: Polymer...


Polyvinyl Chloride PVC
A tough, environmentally indestructible plastic that releases hydrochloric ac...

Find the meaning of the term: Polyvinyl Chloride PVC...


Population
A group of interbreeding organisms occupying a particular space; the number o...

Find the meaning of the term: Population...


Population at Risk
A population subgroup that is more likely to be exposed to a chemical, or is ...

Find the meaning of the term: Population at Risk...


Porosity
Degree to which soil, gravel, sediment, or rock is permeated with pores or ca...

Find the meaning of the term: Porosity...


Portal-of-Entry Effect
A local effect produced in the tissue or organ of first contact between a tox...

Find the meaning of the term: Portal-of-Entry Effect...


Post-Chlorination
Addition of chlorine to plant effluent for disinfectant purposes after the ef...

Find the meaning of the term: Post-Chlorination...


Post-Closure
The time period following the shutdown of a waste management or manufacturing...

Find the meaning of the term: Post-Closure...


Post-Consumer Materials
Materials or finished products that have served their intended use and have b...

Find the meaning of the term: Post-Consumer Materials...


Post-Consumer Recycling
Use of materials generated from residential and consumer waste for new or sim...

Find the meaning of the term: Post-Consumer Recycling...


Potable Water
Water that is safe for drinking and cooking.

Find the meaning of the term: Potable Water...


Potential Dose
The amount of a compound contained in material swallowed, breathed, or applie...

Find the meaning of the term: Potential Dose...


Potentially Responsible Party PRP
Any individual or company--including owners, operators, transporters or gener...

Find the meaning of the term: Potentially Responsible Party PRP...


Potentiation
The ability of one chemical to increase the effect of another chemical.

Find the meaning of the term: Potentiation...


Potentiometric Surface
The surface to which water in an aquifer can rise by hydrostatic pressure.

Find the meaning of the term: Potentiometric Surface...


Pre-Consumer Materials
Materials generated in manufacturing and converting processes such as manufac...

Find the meaning of the term: Pre-Consumer Materials...


Pre-Harvest Interval
The time between the last pesticide application and harvest of the treated cr...

Find the meaning of the term: Pre-Harvest Interval...


Precautionary Principle
When information about potential risks is incomplete, basing decisions about ...

Find the meaning of the term: Precautionary Principle...


Prechlorination
The addition of chlorine at the headworks of a treatment plant prior to other...

Find the meaning of the term: Prechlorination...


Precipitate
A substance separated from a solution or suspension by chemical or physical c...

Find the meaning of the term: Precipitate...


Precipitation
Removal of hazardous solids from liquid waste to permit safe disposal; remova...

Find the meaning of the term: Precipitation...


Precipitator
Pollution control device that collects particles from an air stream.

Find the meaning of the term: Precipitator...


Precursor
In photochemistry, a compound antecedent to a pollutant. For example, volatil...

Find the meaning of the term: Precursor...


Preliminary Assessment
The process of collecting and reviewing available information about a known o...

Find the meaning of the term: Preliminary Assessment...


Prescriptive
Water rights which are acquired by diverting water and putting it to use in a...

Find the meaning of the term: Prescriptive...


Pressed Wood Products
Materials used in building and furniture construction that are made from wood...

Find the meaning of the term: Pressed Wood Products...


Pressure Sewers
A system of pipes in which water, wastewater, or other liquid is pumped to a ...

Find the meaning of the term: Pressure Sewers...


Pretreatment
Processes used to reduce, eliminate, or alter the nature of wastewater pollut...

Find the meaning of the term: Pretreatment...


Prevalent Level Samples
Air samples taken under normal conditions (also known as ambient background s...

Find the meaning of the term: Prevalent Level Samples...


Prevalent Levels
Levels of airborne contaminant occurring under normal conditions.

Find the meaning of the term: Prevalent Levels...


Prevention of Significant Deterioration PSD
EPA program in which state and/or federal permits are required in order to re...

Find the meaning of the term: Prevention of Significant Deterioration PSD...


Primacy
Having the primary responsibility for administering and enforcing regulations.

Find the meaning of the term: Primacy...


Primary Drinking Water Regulation
Applies to public water systems and specifies a contaminant level, which, in ...

Find the meaning of the term: Primary Drinking Water Regulation...


Primary Effect
An effect where the stressor acts directly on the ecological component of int...

Find the meaning of the term: Primary Effect...


Primary Standards
National ambient air quality standards designed to protect human health with ...

Find the meaning of the term: Primary Standards...


Primary Treatment
First stage of wastewater treatment in which solids are removed by screening ...

Find the meaning of the term: Primary Treatment...


Primary Waste Treatment
First steps in wastewater treatment; screens and sedimentation tanks are used...

Find the meaning of the term: Primary Waste Treatment...


Principal Organic Hazardous Constituents
Hazardous compounds monitored during an incinerator's trial burn, selected fo...

Find the meaning of the term: Principal Organic Hazardous Constituents...


Prions
Microscopic particles made of protein that can cause disease.

Find the meaning of the term: Prions...


Prior Appropriation
A doctrine of water law that allocates the rights to use water on a first-com...

Find the meaning of the term: Prior Appropriation...


Probability of Detection
The likelihood, expressed as a percentage, that a test method will correctly ...

Find the meaning of the term: Probability of Detection...


Process Variable
A physical or chemical quantity which is usually measured and controlled in t...

Find the meaning of the term: Process Variable...


Process Verification
Verifying that process raw materials, water usage, waste treatment processes,...

Find the meaning of the term: Process Verification...


Process Wastewater
Any water that comes into contact with any raw material, product, byproduct, ...

Find the meaning of the term: Process Wastewater...


Process Weight
Total weight of all materials, including fuel, used in a manufacturing proces...

Find the meaning of the term: Process Weight...


Producers
Plants that perform photosynthesis and provide food to consumers.

Find the meaning of the term: Producers...


Product Level
The level of a product in a storage tank.

Find the meaning of the term: Product Level...


Product Water
Water that has passed through a water treatment plant and is ready to be deli...

Find the meaning of the term: Product Water...


Products of Incomplete Combustion PICs
Organic compounds formed by combustion. Usually generated in small amounts an...

Find the meaning of the term: Products of Incomplete Combustion PICs...


Project XL
An EPA initiative to give states and the regulated community the flexibility ...

Find the meaning of the term: Project XL...


Propellant
Liquid in a self-pressurized pesticide product that expels the active ingredi...

Find the meaning of the term: Propellant...


Proportionate Mortality Ratio PMR
The number of deaths from a specific cause in a specific period of time per 1...

Find the meaning of the term: Proportionate Mortality Ratio PMR...


Proposed Plan
A plan for a site cleanup that is available to the public for comment.

Find the meaning of the term: Proposed Plan...


Proteins
Complex nitrogenous organic compounds of high molecular weight made of amino ...

Find the meaning of the term: Proteins...


Protocol
A series of formal steps for conducting a test.

Find the meaning of the term: Protocol...


Protoplast
A membrane-bound cell from which the outer wall has been partially or complet...

Find the meaning of the term: Protoplast...


Protozoa
One-celled animals that are larger and more complex than bacteria. May cause ...

Find the meaning of the term: Protozoa...


Public Comment Period
The time allowed for the public to express its views and concerns regarding a...

Find the meaning of the term: Public Comment Period...


Public Health Approach
Regulatory and voluntary focus on effective and feasible risk management acti...

Find the meaning of the term: Public Health Approach...


Public Health Context
The incidence, prevalence, and severity of diseases in communities or populat...

Find the meaning of the term: Public Health Context...


Public Hearing
A formal meeting wherein EPA officials hear the public's views and concerns a...

Find the meaning of the term: Public Hearing...


Public Notice
1. Notification by EPA informing the public of Agency actions such as the iss...

Find the meaning of the term: Public Notice...


Public Water System
A system that provides piped water for human consumption to at least 15 servi...

Find the meaning of the term: Public Water System...


Publicly Owned Treatment Works POTWs
A waste-treatment works owned by a state, unit of local government, or Indian...

Find the meaning of the term: Publicly Owned Treatment Works POTWs...


Pumping Station
Mechanical device installed in sewer or water system or other liquid-carrying...

Find the meaning of the term: Pumping Station...


Pumping Test
A test conducted to determine aquifer or well characteristics.

Find the meaning of the term: Pumping Test...


Purging
Removing stagnant air or water from sampling zone or equipment prior to sampl...

Find the meaning of the term: Purging...




Analytical testing dots