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

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144 results match your search term: A
- A-Scale Sound Level
- A measurement of sound approximating the sensitivity of the human ear, used t...
- Abandoned Well
- A well whose use has been permanently discontinued or which is in a state of ...
- Abatement
- Reducing the degree or intensity of, or eliminating, pollution.
- Abatement Debris
- Waste from remediation activities.
- Absorbed Dose
- In exposure assessment, the amount of a substance that penetrates an exposed ...
- Absorber
- Any material that stops ionizing radiation. Lead, concrete, and steel attenua...
- Absorption
- The process of taking in. The uptake of water, other fluids, or dissolved che...
- Absorption Barrier
- Any of the exchange sites of the body that permit uptake of various substance...
- Accident Site
- The location of an unexpected occurrence, failure or loss, either at a plant ...
- Acclimatization
- The physiological and behavioral adjustments of an organism to changes in its...
- Acequia
- Acequias were important forms of irrigation in the development of agriculture...
- Acid
- A corrosive substance with a pH less than 7.
- Acid Aerosol
- Acidic liquid or solid particles small enough to become airborne. High concen...
- Acid Deposition
- A complex chemical and atmospheric phenomenon that occurs when emissions of s...
- Acid Mine Drainage
- Drainage of water from areas that have been mined for coal or other mineral o...
- Acid Neutralizing Capacity
- Measure of ability of a base (e.g. water or soil) to resist changes in pH.
- Acidic
- The condition of water or soil that contains a sufficient amount of acid subs...
- Action Levels
- 1. Regulatory levels recommended by EPA for enforcement by FDA and USDA when ...
- Activated Carbon
- A highly adsorbent form of carbon used to remove odors and toxic substances f...
- Activated Sludge
- Product that results when primary effluent is mixed with bacteria-laden sludg...
- Activator
- A chemical added to a pesticide to increase its activity.
- Active Ingredient
- In any pesticide product, the component that kills, or otherwise controls, ta...
- Activity Plans
- Written procedures in a school's asbestos-management plan that detail the ste...
- Acute Effect
- An adverse effect on any living organism which results in severe symptoms tha...
- Acute Exposure
- A single exposure to a toxic substance which may result in severe biological ...
- Acute Toxicity
- The ability of a substance to cause severe biological harm or death soon afte...
- Adaptation
- Changes in an organism's physiological structure or function or habits that a...
- Add-on Control Device
- An air pollution control device such as carbon absorber or incinerator that r...
- Adequately Wet
- Asbestos containing material that is sufficiently mixed or penetrated with li...
- Administered Dose
- In exposure assessment, the amount of a substance given to a test subject (hu...
- Administrative Order
- A legal document signed by EPA directing an individual, business, or other en...
- Administrative Order On Consent
- A legal agreement signed by EPA and an individual, business, or other entity ...
- Administrative Procedures Act
- A law that spells out procedures and requirements related to the promulgation...
- Administrative Record
- All documents which EPA considered or relied on in selecting the response act...
- Adsorption
- Removal of a pollutant from air or water by collecting the pollutant on the s...
- Adulterants
- Chemical impurities or substances that by law do not belong in a food, or pes...
- Adulterated
- 1. Any pesticide whose strength or purity falls below the quality stated on i...
- Advanced Treatment
- A level of wastewater treatment more stringent than secondary treatment; requ...
- Advanced Wastewater Treatment
- Any treatment of sewage that goes beyond the secondary or biological water tr...
- Adverse Effects Data
- FIFRA requires a pesticide registrant to submit data to EPA on any studies or...
- Advisory
- A non-regulatory document that communicates risk information to those who may...
- Aerated Lagoon
- A holding and/or treatment pond that speeds up the natural process of biologi...
- Aeration
- A process which promotes biological degradation of organic matter in water. T...
- Aeration Tank
- A chamber used to inject air into water.
- Aerobic
- Life or processes that require, or are not destroyed by, the presence of oxygen.
- Aerobic Treatment
- Process by which microbes decompose complex organic compounds in the presence...
- Aerosol
- 1. Small droplets or particles suspended in the atmosphere, typically contain...
- Affected Landfill
- Under the Clean Air Act, landfills that meet criteria for capacity, age, and ...
- Affected Public
- 1.The people who live and/or work near a hazardous waste site. 2. The human p...
- Afterburner
- In incinerator technology, a burner located so that the combustion gases are ...
- Age Tank
- A tank used to store a chemical solution of known concentration for feed to a...
- Agent
- Any physical, chemical, or biological entity that can be harmful to an organi...
- Agent Orange
- A toxic herbicide and defoliant used in the Vietnam conflict, containing 2,4,...
- Agricultural Pollution
- Farming wastes, including runoff and leaching of pesticides and fertilizers; ...
- Agricultural Waste
- Poultry and livestock manure, and residual materials in liquid or solid form ...
- Agroecosystem
- Land used for crops, pasture, and livestock; the adjacent uncultivated land t...
- AHERA Designated Person ADP
- A person designated by a Local Education Agency to ensure that the AHERA requ...
- Air
- The surface between the vadose zone and ambient oil; the pressure of oil in t...
- Air Binding
- Situation where air enters the filter media and harms both the filtration and...
- Air Changes Per Hour ACH
- The movement of a volume of air in a given period of time; if a house has one...
- Air Cleaning
- Indoor-air quality-control strategy to remove various airborne particulates a...
- Air Contaminant
- Any particulate matter, gas, or combination thereof, other than water vapor.
- Air Curtain
- A method of containing oil spills. Air bubbling through a perforated pipe cau...
- Air Exchange Rate
- The rate at which outside air replaces indoor air in a given space.
- Air Gap
- Open vertical gap or empty space that separates drinking water supply to be p...
- Air Handling Unit
- Equipment that includes a fan or blower, heating and/or cooling coils, regula...
- Air Mass
- A large volume of air with certain meteorological or polluted characteristics...
- Air Padding
- Pumping dry air into a container to assist with the withdrawal of liquid or t...
- Air Permeability
- Permeability of soil with respect to air. Important to the design of soil-gas...
- Air Plenum
- Any space used to convey air in a building, furnace, or structure. The space ...
- Air Pollutant
- Any substance in air that could, in high enough concentration, harm man, othe...
- Air Pollution
- The presence of contaminants or pollutant substances in the air that interfer...
- Air Pollution Control Device
- Mechanism or equipment that cleans emissions generated by a source (e.g. an i...
- Air Pollution Episode
- A period of abnormally high concentration of air pollutants, often due to low...
- Air Quality Criteria
- The levels of pollution and lengths of exposure above which adverse health an...
- Air Quality Standards
- The level of pollutants prescribed by regulations that are not be exceeded du...
- Air Sparging
- Injecting air or oxygen into an aquifer to strip or flush volatile contaminan...
- Air Stripping
- A treatment system that removes volatile organic compounds (VOCs) from contam...
- Air Toxics
- Any air pollutant for which a national ambient air quality standard (NAAQS) d...
- Airborne Particulates
- Total suspended particulate matter found in the atmosphere as solid particles...
- Airborne Release
- Release of any pollutant into the air.
- Alachlor
- A herbicide, marketed under the trade name Lasso, used mainly to control weed...
- Alar
- Trade name for daminozide, a pesticide that makes apples redder, firmer, and ...
- Aldicarb
- An insecticide sold under the trade name Temik. It is made from ethyl isocyan...
- Algae
- Simple rootless plants that grow in sunlit waters in proportion to the amount...
- Algal Blooms
- Sudden spurts of algal growth, which can affect water quality adversely and i...
- Algicide
- Substance or chemical used specifically to kill or control algae.
- Aliquot
- A measured portion of a sample taken for analysis. One or more aliquots make ...
- Alkaline
- The condition of water or soil which contains a sufficient amount of alkali s...
- Alkalinity
- The capacity of bases to neutralize acids. An example is lime added to lakes ...
- Allergen
- A substance that causes an allergic reaction in individuals sensitive to it.
- Alluvial
- Relating to and/or sand deposited by flowing water.
- Alternate Method
- Any method of sampling and analyzing for an air or water pollutant that is no...
- Alternative Compliance
- A policy that allows facilities to choose among methods for achieving emissio...
- Alternative Fuels
- Substitutes for traditional liquid, oil-derived motor vehicle fuels like gaso...
- Alternative Remedial Contract Strategy Contractors
- Government contractors who provide project management and technical services ...
- Ambient Air
- Any unconfined portion of the atmosphere
- Ambient Measurement
- A measurement of the concentration of a substance or pollutant within the imm...
- Ambient Medium
- Material surrounding or contacting an organism (e.g. outdoor air, indoor air,...
- Ambient Temperature
- Temperature of the surrounding air or other medium.
- Amprometric Titration
- A way of measuring concentrations of certain substances in water using an ele...
- Anaerobic
- A life or process that occurs in, or is not destroyed by, the absence of oxygen.
- Anaerobic Decomposition
- Reduction of the net energy level and change in chemical composition of organ...
- Analyte
- A compound or property that is to be determined and/or analyzed.
- Animal Dander
- Tiny scales of animal skin, a common indoor air pollutant.
- Animal Studies
- Investigations using animals as surrogates for humans with the expectation th...
- Anisotropy
- In hydrology, the conditions under which one or more hydraulic properties of ...
- Annular Space
- The space between two concentric tubes or casings, or between the casing and ...
- Antagonism
- Interference or inhibition of the effect of one chemical by the action of ano...
- Antarctic Ozone Hole
- Refers to the seasonal depletion of ozone in the upper atmosphere above a lar...
- Anti-Degradation Clause
- Part of federal air quality and water quality requirements prohibiting deteri...
- Anti-Microbial
- An agent that kills microbes.
- Applicable or Relevant and Appropriate Requirements ARARs
- Any state or federal statute that pertains to protection of human life and th...
- Applied Dose
- In exposure assessment, the amount of a substance in contact with the primary...
- Aqueous
- Something made up of water.
- Aqueous Solubility
- The maximum concentration of a chemical that will dissolve in pure water at a...
- Aquifer
- An underground geological formation, or group of formations, containing water...
- Aquifer Test
- A test to determine hydraulic properties of an aquifer.
- Aquitard
- Geological formation that may contain groundwater but is not capable of trans...
- Architectural Coatings
- Coverings such as paint and roof tar that are used on exteriors of buildings.
- Area of Review
- In the UIC program, the area surrounding an injection well that is reviewed d...
- Area Source
- Any source of air pollution that is released over a relatively small area but...
- Aromatics
- A type of hydrocarbon, such as benzene or toluene, with a specific type of ri...
- Arsenicals
- Pesticides containing arsenic.
- Artesian Aquifer or Well
- Water held under pressure in porous rock or soil confined by impermeable geol...
- Asbestos
- A mineral fiber that can pollute air or water and cause cancer or asbestosis ...
- Asbestos Abatement
- Procedures to control fiber release from asbestos-containing materials in a b...
- Asbestos Assessment
- In the asbestos-in-schools program, the evaluation of the physical condition ...
- Asbestos Program Manager
- A building owner or designated representative who supervises all aspects of t...
- Asbestos-Containing Waste Materials ACWM
- Mill tailings or any waste that contains commercial asbestos and is generated...
- Asbestosis
- A disease associated with inhalation of asbestos fibers. The disease makes br...
- Ash
- The mineral content of a product remaining after complete combustion.
- Assay
- A test for a specific chemical, microbe, or effect.
- Assessment Endpoint
- In ecological risk assessment, an explicit expression of the environmental va...
- Assimilation
- The ability of a body of water to purify itself of pollutants.
- Assimilative Capacity
- The capacity of a natural body of water to receive wastewaters or toxic mater...
- Association of Boards of Certification
- An international organization representing boards which certify the operators...
- Attainment Area
- An area considered to have air quality as good as or better than the national...
- Attenuation
- The process by which a compound is reduced in concentration over time, throug...
- Attractant
- A chemical or agent that lures insects or other pests by stimulating their se...
- Attrition
- Wearing or grinding down of a substance by friction. Dust from such processes...
- Availability Session
- Informal meeting at a public location where interested citizens can talk with...
- Available Chlorine
- A measure of the amount of chlorine available in chlorinated lime, hypochlori...
- Avoided Cost
- The cost a utility would incur to generate the next increment of electric cap...
Find the meaning of the term: A-Scale Sound Level...
Find the meaning of the term: Abandoned Well...
Find the meaning of the term: Abatement...
Find the meaning of the term: Abatement Debris...
Find the meaning of the term: Absorbed Dose...
Find the meaning of the term: Absorber...
Find the meaning of the term: Absorption...
Find the meaning of the term: Absorption Barrier...
Find the meaning of the term: Accident Site...
Find the meaning of the term: Acclimatization...
Find the meaning of the term: Acequia...
Find the meaning of the term: Acid...
Find the meaning of the term: Acid Aerosol...
Find the meaning of the term: Acid Deposition...
Find the meaning of the term: Acid Mine Drainage...
Find the meaning of the term: Acid Neutralizing Capacity...
Find the meaning of the term: Acidic...
Find the meaning of the term: Action Levels...
Find the meaning of the term: Activated Carbon...
Find the meaning of the term: Activated Sludge...
Find the meaning of the term: Activator...
Find the meaning of the term: Active Ingredient...
Find the meaning of the term: Activity Plans...
Find the meaning of the term: Acute Effect...
Find the meaning of the term: Acute Exposure...
Find the meaning of the term: Acute Toxicity...
Find the meaning of the term: Adaptation...
Find the meaning of the term: Add-on Control Device...
Find the meaning of the term: Adequately Wet...
Find the meaning of the term: Administered Dose...
Find the meaning of the term: Administrative Order...
Find the meaning of the term: Administrative Order On Consent...
Find the meaning of the term: Administrative Procedures Act...
Find the meaning of the term: Administrative Record...
Find the meaning of the term: Adsorption...
Find the meaning of the term: Adulterants...
Find the meaning of the term: Adulterated...
Find the meaning of the term: Advanced Treatment...
Find the meaning of the term: Advanced Wastewater Treatment...
Find the meaning of the term: Adverse Effects Data...
Find the meaning of the term: Advisory...
Find the meaning of the term: Aerated Lagoon...
Find the meaning of the term: Aeration...
Find the meaning of the term: Aeration Tank...
Find the meaning of the term: Aerobic...
Find the meaning of the term: Aerobic Treatment...
Find the meaning of the term: Aerosol...
Find the meaning of the term: Affected Landfill...
Find the meaning of the term: Affected Public...
Find the meaning of the term: Afterburner...
Find the meaning of the term: Age Tank...
Find the meaning of the term: Agent...
Find the meaning of the term: Agent Orange...
Find the meaning of the term: Agricultural Pollution...
Find the meaning of the term: Agricultural Waste...
Find the meaning of the term: Agroecosystem...
Find the meaning of the term: AHERA Designated Person ADP...
Find the meaning of the term: Air...
Find the meaning of the term: Air Binding...
Find the meaning of the term: Air Changes Per Hour ACH...
Find the meaning of the term: Air Cleaning...
Find the meaning of the term: Air Contaminant...
Find the meaning of the term: Air Curtain...
Find the meaning of the term: Air Exchange Rate...
Find the meaning of the term: Air Gap...
Find the meaning of the term: Air Handling Unit...
Find the meaning of the term: Air Mass...
Find the meaning of the term: Air Padding...
Find the meaning of the term: Air Permeability...
Find the meaning of the term: Air Plenum...
Find the meaning of the term: Air Pollutant...
Find the meaning of the term: Air Pollution...
Find the meaning of the term: Air Pollution Control Device...
Find the meaning of the term: Air Pollution Episode...
Find the meaning of the term: Air Quality Criteria...
Find the meaning of the term: Air Quality Standards...
Find the meaning of the term: Air Sparging...
Find the meaning of the term: Air Stripping...
Find the meaning of the term: Air Toxics...
Find the meaning of the term: Airborne Particulates...
Find the meaning of the term: Airborne Release...
Find the meaning of the term: Alachlor...
Find the meaning of the term: Alar...
Find the meaning of the term: Aldicarb...
Find the meaning of the term: Algae...
Find the meaning of the term: Algal Blooms...
Find the meaning of the term: Algicide...
Find the meaning of the term: Aliquot...
Find the meaning of the term: Alkaline...
Find the meaning of the term: Alkalinity...
Find the meaning of the term: Allergen...
Find the meaning of the term: Alluvial...
Find the meaning of the term: Alternate Method...
Find the meaning of the term: Alternative Compliance...
Find the meaning of the term: Alternative Fuels...
Find the meaning of the term: Alternative Remedial Contract Strategy Contractors...
Find the meaning of the term: Ambient Air...
Find the meaning of the term: Ambient Measurement...
Find the meaning of the term: Ambient Medium...
Find the meaning of the term: Ambient Temperature...
Find the meaning of the term: Amprometric Titration...
Find the meaning of the term: Anaerobic...
Find the meaning of the term: Anaerobic Decomposition...
Find the meaning of the term: Analyte...
Find the meaning of the term: Animal Dander...
Find the meaning of the term: Animal Studies...
Find the meaning of the term: Anisotropy...
Find the meaning of the term: Annular Space...
Find the meaning of the term: Antagonism...
Find the meaning of the term: Antarctic Ozone Hole...
Find the meaning of the term: Anti-Degradation Clause...
Find the meaning of the term: Anti-Microbial...
Find the meaning of the term: Applicable or Relevant and Appropriate Requirements ARARs...
Find the meaning of the term: Applied Dose...
Find the meaning of the term: Aqueous...
Find the meaning of the term: Aqueous Solubility...
Find the meaning of the term: Aquifer...
Find the meaning of the term: Aquifer Test...
Find the meaning of the term: Aquitard...
Find the meaning of the term: Architectural Coatings...
Find the meaning of the term: Area of Review...
Find the meaning of the term: Area Source...
Find the meaning of the term: Aromatics...
Find the meaning of the term: Arsenicals...
Find the meaning of the term: Artesian Aquifer or Well...
Find the meaning of the term: Asbestos...
Find the meaning of the term: Asbestos Abatement...
Find the meaning of the term: Asbestos Assessment...
Find the meaning of the term: Asbestos Program Manager...
Find the meaning of the term: Asbestos-Containing Waste Materials ACWM...
Find the meaning of the term: Asbestosis...
Find the meaning of the term: Ash...
Find the meaning of the term: Assay...
Find the meaning of the term: Assessment Endpoint...
Find the meaning of the term: Assimilation...
Find the meaning of the term: Assimilative Capacity...
Find the meaning of the term: Association of Boards of Certification...
Find the meaning of the term: Attainment Area...
Find the meaning of the term: Attenuation...
Find the meaning of the term: Attractant...
Find the meaning of the term: Attrition...
Find the meaning of the term: Availability Session...
Find the meaning of the term: Available Chlorine...
Find the meaning of the term: Avoided Cost...