Environment terminology · MLC-0121

Environment terms: E (1,815)

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Excretion1. The process by which waste matter is discharged from the body
Excretion KineticsRate of clearance of substance metabolites as measured in unit time. Elimination occurs as a result of...
Excursion1. Departure from an indicator range established for monitoring under this part, consistent with any...
Executive Agency1. Any executive department or independent establishment in the executive branch of the U.S. Government...
Executive Branch AgencyAny ‘‘executive agency,’’ as defined in 5 U.S.C. 105; the United States Postal Service; and any other...
Executive OrderOfficial documents, numbered consecutively, through which the President of the United States manages the...
Executive Order 12873Federal Acquisition, Recycling, and Waste Minimization (http://www.epa.gov/oppt/epp/pubs/eo12873.pdf )...
Executive Order 13101E.O. 13101 was revoked and replaced by E.O. 13423 in January 2007. Entitled Greening the Government Through...
Executive Order 13423Entitled Strengthening Federal Environmental, Energy, and Transportation Management, E.O. 13423...
Executive ReportAn abbreviated report that has been tailored specifically to addresses the concerns and questions of a person...
Executive SummaryA non-technical summary statement designed to provide a quick overview of the full-length report on which it...
Exempt Compound1. Specific compound that is not considered a VOC due to negligible photochemical reactivity. The exempt...
EXEMPT PROPERTYTangible personal property acquired in whole or in part with Federal funds, where the Federal awarding agency...
Exempt Solvent1. Specific organic compounds not subject to requirements of regulation because they are deemed by EPA to be...
Exempt VehicleExempt vehicles meet certain criteria that allow them to be exempt from EPA emission standards and/or other...
Exempt Vehicle/EngineExempt vehicles or engines meet certain criteria that allow them to be exempt from EPA emission standards...
Exempted Aquifer1. An aquifer, or a portion of an aquifer, that meets the criteria for a USDW, for which protection under the...
Exempted Engine1. Meaning given in 40 CFR 1068.30. [40 CFR 1054.801 (CFR 2013)][40 CFR 1036.801 (CFR 2013)][40 CFR 1037.801...
Exempted Equipment1. Meaning given in 40 CFR 1068.30. [40 CFR 1054.801 (CFR 2013)][40 CFR 1036.801 (CFR 2013)][40 CFR 1037.801...
Exempted Locomotive1. Meaning given in 40 CFR 1068.30. [40 CFR 1054.801 (CFR 2013)][40 CFR 1036.801 (CFR 2013)][40 CFR 1037.801...
Exempted Reporting Chemical1. The following groups or categories of chemical substances are exempted from some or all of the reporting...
Exemption1. State or USEPA permission for a water system not to meet a certain drinking water standard. An exemption...
Exemption ApplicationAny application submitted to EPA under section 5(h)(2) of the Act.
Exemption CategoryCategory of chemical substances for which a person(s) has applied for or been granted an exemption under...
Exemption HolderManufacturer or processor, subject to a test rule, that has received an exemption under sections 4(c)(1) or...
Exemption NoticeAny notice submitted to EPA under § 723.175 of this chapter.
Exemption Request]Any application submitted to EPA under subparts E, F, or G of this part.
Exemption Request SubmissionAny MCAN or exemption request submitted to EPA under this part.
ExfiltrationAir leakage outward through cracks and interstices and through ceilings, floors, and walls of a space or...
ExhalationThe act of breathing out.
ExhaustThe combination of gases that is released from an automobile.
Exhaust AirAir removed from a space and not used therein.
Exhaust DamperFlow control device that prevents the airperchloroethylene gas-vapor stream from exiting the dry cleaning...
Exhaust Emissions1. Matter emitted into the atmosphere from any opening downstream from the exhaust port of a nonroad engine.
Exhaust Emissions Deterioration Factor1. Difference between exhaust emissions at the end of useful life and exhaust emissions at the low mileage...
Exhaust Gas1. Gaseous waste product from combustion usually emitted from a chimney, flue or pipe
Exhaust Gas Recirculation1. Emission control technology that reduces emissions by routing exhaust gases that had been exhausted from...
Exhaust PlumeA plume is a visible or measurable emission or discharge of a contaminant from a given point of origin into...
Exhaust StreamGases emitted from a process through a conveyance as defined in this subpart. [40 CFR 63.7765 (CFR 2013)]
Exhaust System1. System comprised of a combination of components which provides for enclosed flow of exhaust gas from...
Exhaust VentilationMechanical removal of air from a portion of a building (e.g., piece of equipment, room, or general area).
ExhibitA relatively large, usually three-dimensional, communications product; can range from table-top size to a...
Existence Value1. A value we place on an environmental amenity simply because we want it to exist.
Existing Affected Source1. Any affected source the construction or reconstruction of which is commenced on or before September 13...
Existing Agricultural LandCropland, pastureland, and land enrolled in the Conservation Reserve Program (administered by the U.S...
Existing BuildingThat the owner or operator has obtained all necessary preconstruction approvals or permits required by...
Existing CCR Surface ImpoundmentCCR surface impoundment that receives CCR both before and after October 19, 2015, or for which construction...
Existing Chemical Exposure LimitAirborne concentration calculated as an eight (8)-hour time-weighted average (TWA). [
Existing Chemical Exposure Limit Action LevelConcentration of airborne methylene chloride of 1 part per million (1 ppm) calculated as an 8-hour time...
Existing Coal Combustion Residuals LandfillCCR landfill that receives CCR both before and after October 19, 2015, or for which construction commenced...
Existing Control DeviceFor the purposes of these standards, an air pollution control device that has been in operation on or before...
Existing Control MeasureAny Federally enforceable national, State, or local control measure that has been approved in the SIP and...
Existing Conventional ImpoundmentAny conventional uranium byproduct material or tailings impoundment which is licensed to accept additional...
existing dataData that have been collected, derived, stored, or reported in the past or by other parties (for a different...
Existing Dental SourceDental discharger that is not a new source.
Existing Effluent QualityLevel at which the pollutants identified in § 430.24(a)(1) are present in the effluent of a mill “enrolled”...
Existing electronic document receiving systemAs defined in § 3.3 of CROMERR, an electronic document receiving system that is being used to receive...
Existing Facility1. Any facility that is not a new facility.
Existing FlowThe average flow volume discharged from a facility based on monitored data.
Existing Great Lakes DischargerAny building, structure, facility, or installation from which there is or may be a “discharge of pollutants”...
Existing Hazardous Waste Management FacilityFacility which was in operation or for which construction commenced on or before November 19, 1980. A...
Existing Indirect DischargerOnly those two iron blast furnace operations with discharges to publicly owned treatment works prior to May...
Existing Injection WellInjection well other than a new injection well.[40 CFR 146.3 (CFR 2018)]
Existing Municipal Solid Waste Landfill UnitAny municipal solid waste landfill unit that is receiving solid waste as of the appropriate dates specified...
Existing Outboard Engine TechnologyOutboard engine or a personal watercraft engine which was in production for the 1997 or any previous model...
Existing Outer Continental Shelf SourceShall have the meaning given in the applicable requirements incorporated into §§ 55.13 and 55.14 of this...
Existing Personal Watercraft Engine TechnologyOutboard engine or a personal watercraft engine which was in production for the 1997 or any previous model...
Existing Portion1. That land surface area of an existing waste management unit, included in the original Part A permit...
Existing Process UnitAny process unit that is not a new process unit. [40 CFR 63.1312 (CFR 2013)]
Existing Sewage Sludge Incineration UnitSewage sludge incineration unit the construction of which is commenced on or before October 14, 2010.
Existing source1. Any source of discharge, the construction or operation of which commenced before the publication by EPA of...
Existing StackThat the owner or operator had (1) begun, or caused to begin, a continuous program of physical on-site...
Existing Stationary FacilityAny of the following stationary sources of air pollutants, including any reconstructed source, which was not...
Existing TankTank that is used for the storage or processing of used oil and that is in operation, or for which...
Existing Tank System1. Tank system or component that is used for the storage or treatment of hazardous waste and that is in...
Existing Tank System ComponentTank system or component that is used for the storage or treatment of hazardous waste and that is in...
Existing UnitUnit (including a unit subject to section 111 of the Act) that commenced commercial operation before November...
Existing Use1. Use actually attained in the waterbody on or after November 28, 1975, whether or not it is included in the...
Existing UsesThose uses actually attained in the waterbody on or after November 28, 1975, whether they are included in the...
Existing Vapor Processing SystemVapor processing system [capable of achieving emissions to the atmosphere no greater than 80 milligrams of...
Existing VesselAny vessel on which construction was initiated before January 30, 1975;
Existing Violation Degeneration1. To cause a nonattainment area to exceed a standard more often or to cause a violation at a greater...
Existing Water UseThose uses actually attained in the water body on or after November 28, 1975, whether or not they are...
Exit CostThe costs of proper closure, decommiessioning, and clean-up at the end of the useful life of a process...
ExocoelIn coral and anemone polyps, the space between mesenteries belonging to different pairs.
Exocrine PancreasAn enzyme producing region of the pancreatic tissue containing the pancreatic acini and exocrine intralobular...
ExocytosisCellular release of secretory products from within membrane-limited vesicles or granules.
Exocytosis RegulationRegulation of Exocytosis consists of subcellular biochemical pathways and mechanisms that control release of...
Exoenzyme ReleaseSecretion of certain enzymes by filamentous fungi in response to environmental conditions
Exogenous ChemicalA substance produced outside of the biological system in which it is found
Exogenous DNADNA originating outside an organism that has been introducted into the organism.
Exon1. A nucleotide sequence (of DNA or RNA) in a gene that codes for part or all of the gene product or for some...
Exoskeleton1. Hard outer shell that provides an invertebrate with support and protection. Blue crabs and other...
Exosphere1. This is the outermost layer of the atmosphere. It extends from the top of the thermosphere to 6,200 miles...
ExothermicCharacterized by or formed with evolution of heat
exoticNon-native plant and animal species.
Exotic PlantA plant that is not born, growing, or produced naturally (native) in an area, region, or country. Syn...
Exotic Species1. A species that is not indigenous to a region.
Exotoxicological BenchmarksNumerical values that represent concentrations of contaminants in abiotic media (sediments, water, soil) or...
ExozoochoryThe dispersal of plant seeds or spores accidentally attached to the outside of an animal's body; also called...
Expandable PolystyrenePolystyrene bead to which a blowing agent has been added using either an in-situ suspension process or a...
Expandable Polystyrene ResinPolystyrene bead to which a blowing agent has been added using either an in-situ suspension process or a...
Expanded Bead BlowingExpanded plastics are created when the plastic beads are placed into a mold, and a blowing agent or gas -...
Expanded Site InspectionAdditional study undertaken if it is determined that data collected in the site inspection is not sufficient...
Expanded Site Inspection/Remedial Investigation1. An assessment that characterizes the magnitude and severity of hazardous waste sites.
Expanded Uncertainty1. Measure of uncertainty that defines an interval about the measurement result y within which the value of...
Expected BaselineAnticipated value of a monitored parameter that is compared to the measured monitored parameter.
Expected pollutantA pollutant which EPA has identified as likely to occur from an emissions process and has determined should...
Expected Statistical ValueThe probabilistically weighted outcome that defines a statistical mean and a measure of the central tendency...
Expected Useful LifeThe average amount of time, in years, that a system or component is estimated to function when installed new.
Expected valueThe probabilistically weighted outcome that defines a statistical mean and a measure of the central tendency...
Expected Value of InformationThe expected increase in the value (or decrease in the loss) associated with obtaining more information about...
ExpectorantAgents that increase mucous excretion. Mucolytic agents, that is drugs that liquefy mucous secretions, are...
Expedited HearingHearing commenced as the result of the issuance of a notice of intention to suspend or the suspension of a...
expedited site assessmentA process for collecting and evaluating site information in a single mobilization. Parameters assessed...
expendable tipA disposable steel or aluminum tip that attaches to the end of DP rods. The tip seals the DP rods or sampling...
EXPENDITURE REPORT1. For non construction grants, the SF 269 "Financial Status Report" (FSR) (or equivalent report).
ExpenseMoney spent by the utility to continue its ongoing operations.
Expense Ratio1. Expense Ratio = Operating Expense / Total Expense
ExperimentManipulation of a candidate cause through elimination of a source or alteration of exposure, to evaluate the...
Experimental Animal1. Any animal used in any research investigation involving the feeding or other administration of, or...
Experimental DataData produced by an experimental or quasi-experimental design.
Experimental DesignA research design in which the researcher has control over the selection of participants in the study, and...
Experimental FurnaceGlass melting furnace with the sole purpose of operating to evaluate glass melting processes, technologies...
Experimental GroupA group of individuals participating in the program activities or receiving the program services being...
Experimental ModelRepresentation of an object or process which is based on empirical interaction with the actual world.
Experimental MortalityThe loss of subjects from an experiment due to such factors as illness, lack of interest, or refusal to...
Experimental Process LinePolymer or copolymer manufacturing process line with the sole purpose of operating to evaluate polymer...
Experimental Start DateFirst date the test atmosphere is applied to the test system. [40 CFR 79.63 (CFR 2013)][40 CFR 160.3 (CFR...
experimental study1. A study in which the investigator specifies the exposure category for each individual (clinical trial) or...
Experimental TechnologyTechnology which has not been proven feasible under the conditions in which it is being tested.
Experimental Termination DateLast date on which data are collected directly from the study. [40 CFR 79.63 (CFR 2013)][40 CFR 160.3 (CFR...
Experimental Use Permit1. Obtained by manufacturers for testing new pesticides or uses thereof whenever they conduct experimental...
Experimental Use Permit ReviewReview of an application for a permit pursuant to section 5 of FIFRA to apply a limited quantity of a...
Experimental Use PermitsAn EUP is a permit authorized under FIFRA section 5 that allows applicants to develop data to support an...
Experimental WellsClass V wells that are used to test new technologies. Wells will not be classified as experimental if the...
ExperimentationManipulation of a candidate cause through elimination of a source or alteration of exposure, to evaluate the...
Expert Elicitation1. A systematic process for quantifying, typically in probabilistic terms, expert judgments about uncertain...
Expert Elicitation Method1. A process for obtaining expert beliefs about subjective quantities and probabilities. Typically...
Expert JudgementA method of inference based on the knowledge and skill of qualified assessors, rather than a formal analysis.
expert judgment1. An inferential opinion of a specialist or group of specialists within an area of their expertise. Expert...
Expert SystemA computer program that mimics the judgment of experts by following sets of chemical-specific knowledge rules...
Expiration DateThe date (often shown on the Declarations Page of the policy) when coverage will stop. It may be a specific...
Explanation of Significant Differences1. Document issued by the agency leading a cleanup that describes to the public significant changes made to a...
Explicit Margin of SafetyThis refers to the Explicit Margin of Safety for the Associated Pollutant as identified in the TMDL.
Exploitation CompetitionCompetition in which two or more organisms consume the same limited resource (Ehrlich and Roughgarden...
exploration1. The search for valuable minerals by geological, geochemical, geophysical, or intrusive physical...
Exploration WellA well drilled into the earth to see if there are deposits of hydrocarbons (i.e. oil or natural gas) under...
Exploratory FacilityAny fixed or mobile structure subject to this subpart that is engaged in the drilling of wells to determine...
Exploratory Outer Continental Shelf SourceAny OCS source that is a temporary operation conducted for the sole purpose of gathering information. This...
Exploratory SourceAny OCS source that is a temporary operation conducted for the sole purpose of gathering information. This...
ExplosiveCharacterized by or relation to bursting forth with sudden violence or noise from internal energy; relating...
Explosive LimitsThe amounts of vapor in the air that form explosive mixtures; limits are expressed as lower and upper limits...
Explosive Limits (Chemical)The amounts of vapor in air that form explosive mixtures. These limits are expressed as lower and upper...
Explosives1. Dynamite, nitroglycerin, cyclotrimethylene trinitramine (RDX), cyclotetramethylene tetranitramine (HMX)...
Explosives AttackBombing Using Improvised Explosive Device
Explosives Emergency ResponseAll immediate response activities by an explosives and munitions emergency response specialist to control...
Explosives or Munitions EmergencySituation involving the suspected or detected presence of unexploded ordnance (UXO), damaged or deteriorated...
Explosives or Munitions Emergency Response SpecialistAn individual trained in chemical or conventional munitions or explosives handling, transportation...
ExplosivityCharacterized by or relation to bursting forth with sudden violence or noise from internal energy; relating...
Exponential DistributionA family of continuous probability distribution functions, whose shape is determined by its rate parameter...
Exponential growthGrowth in which some quantity, such as population size, increases by a constant percentage of the whole...
exponential growth (rate)A rate of growth of an organism, a part of an organism, or a population of organisms which, when graphed...
Export1. Transport a product from inside the United States to persons outside the United States, excluding any such...
Export Base AnalysisMultiplier analysis method for estimating regional economic effects of projects. It is particularly suited to...
Export Exemption1. Exemption granted under § 89.1004(b) for the purpose of exporting new nonroad engines.
Export Pesticide DeviceDevice, as defined in FIFRA section 2(h), that is intended solely for export from the United States to...
Export Pesticide ProductPesticide product, as defined in § 152.3 of this chapter, that is intended solely for export from the United...
Export Production AllowancePrivileges granted by § 82.18(b) to produce HCFC-141b for export following the phaseout of HCFC-141b on...
Exported GoodsMerchandise transported out of the United States to foreign countries.
Exporter1. Any person, company or organization of record that transfers for sale or for other benefit, domestic...
Exports1. Refers to municipal solid waste and recyclables that are transported outside the state or locality where...
exposedA group whose members have been exposed to a supposed cause of disease or health state of interest, or...
Exposed foodsFoods grown above ground.
Exposed Gasket Surface AreaSurface area of the gasket inside the fuel tank that is exposed to fuel or fuel vapor. For the purposes of...
Exposed Group1. A group whose members have had contact with a suspected cause of, or possess a characteristic that is a...
Exposed population1. The exposed population is the population that is likely to come in contact with a chemical. The population...
ExposomeThe measure of all the exposures of an individual in a lifetime and how those exposures relate to health.
Ex-post Facto DesignA research design in which all group selection, pretest data, and posttest data are collected after...
Exposure1. Contact with a substance by swallowing, breathing, or touching the skin or eyes. Exposure may be...
Exposure Assessment1. The process of finding out how people come into contact with a hazardous substance, how often and for how...
Exposure Assessment TypeThe type of assessment might refer to whether the assessment is considering aggregate or cumulative exposures...
Exposure by ChemicalExposure to certain possibly harmful chemical substances
Exposure by LifestageContact with a substance by swallowing, breathing, or touching the skin or eyes by the age of the exposed...
Exposure Characterization1. A portion of the analysis phase of ecological risk assessment that evaluates the interaction of the...
Exposure Characterization ModelRepresentation of processes that expose organisms to toxicants
Exposure Classification AlgorithmAlgorithm to sort the likelihood of exposure into several classes.
Exposure CoefficientTerm which combines information on the frequency, mode, and magnitude of contact with contaminated medium to...
Exposure Concentration1. The concentration of a chemical or other pollutant representing a health threat in a given environment.
Exposure DescriptorAn estimate for a specific point on the exposure distribution (e.g., mean, median, 95th percentile, maximum)...
Exposure duration1. Length of time over which contact with the contaminant lasts.
Exposure eventThe occurrence of continuous contact between an agent and a target.
Exposure factor1. Factors related to human behavior and characteristics that help determine an individual's exposure to an...
Exposure factorsFactors related to human behavior and characteristics that help determine an individual's exposure to a...
Exposure frequency1. The number of exposure events in an exposure duration.
Exposure Frequency and Duration ModelRepresentation of the exposure processes that are characterized by frequency and duration
Exposure IndicatorA characteristic of the environment measured to provide evidence of the occurrence or magnitude of a response...
Exposure intervalA period of constant contact between an agent and a target. [European Environment Agency Glossary...
exposure investigation1. In public health assessment, the collection and analysis of site-specific information and biologic tests...
Exposure LevelThe amount (concentration) of a chemical at the absorptive surfaces of an organism.
Exposure Level (chemical)The amount (concentration) of a chemical at the absorptive surfaces of an organism.
Exposure loadingThe exposure mass divided by the exposure surface area. For example, a dermal exposure measurement based on a...
Exposure Location ModelRepresentation of exposure processes that are characterized by location
Exposure MediumThe contaminated environmental medium to which an individual is exposed, such as soil, water, sediment and...
exposure model1. The primary objective of exposure modeling is to estimate the dose of pollutant which humans or animals...
Exposure modeling1. RSEI's risk-related results include a calculated surrogate dose, which is estimated through exposure...
Exposure or risk descriptorAn estimate for a specific point on the exposure distribution (e.g., mean, median, 95th percentile, maximum)...
Exposure Pathway1. RAGS Volume I, Part A, Chapter 6 defines exposure pathway as "the course a chemical or physical agent...
Exposure Pathway Model1. A model in which potential pathways of exposure are identified for the selected receptor species.
Exposure Pathways1. A route by which organisms are exposed to radiation or radionuclides[DB18.1]. The three basic radiation...
exposure periodThe time of continuous contact between an agent and a target. [IPCS 2004]
Exposure Point1. The potential contact between a person and a contaminant within an exposure medium.
Exposure Point ConcentrationThe value that represents a conservative estimate of the chemical concentration available from a particular...
Exposure Profile1. The product of characterizing exposure in the analysis phase of ecological risk assessment. The exposure...
Exposure (radiation)Radiation exposure, also called irradiation, occurs when radioactive material or a radiation machine emits...
Exposure Route1. The mechanism for which a contaminant comes in contact with a person (e.g., by ingestion, inhalation...
exposure route versus exposure source1. Exposure route (also known as "route of exposure") most commonly refers to the manner in which a hazardous...
Exposure RoutesThe way a chemical or pollutant enters an organism after contact; i.e., by ingestion, inhalation, or dermal...
Exposure Scenario1. A set of assumptions concerning how an exposure takes place, including assumptions about the exposure...
Exposure settingThe physical setting where an exposure of interest occurs and is defined by the boundaries of the analysis...
Exposure surface1. A surface on a target where an agent is present. Examples of outer exposure surfaces include the exterior...
Exposure timeThe length of time a specific mail-in device must be in contact with radon or radon decay products to get an...
exposure unitIn geographical information system applications, the geographical area in which a receptor moves and contacts...
Exposure-Dose Reconstruction1. A method of estimating the amount of people's past exposure to hazardous substances. Computer and...
Exposure-Response1. The relationship between the intensity, frequency, or duration of exposure to a stressor and the...
Exposure-Response Relationship1. The relationship between exposure level and the incidence of adverse effects.
Exposure-Wide Association StudyStudy aimed at finding linkages between exposures to toxic substances and harmful effects.
Express AuthorizationExpress Authorization is a restructuring of the components of an authorization application that helps states...
Expressed Sequence TagA small part of the active part of a gene, made from cDNA which can be used to fish the rest of the gene out...
Extant Animal SpeciesSpecies that is currently in existence (the opposite of extinct).
Extant Plant SpeciesSpecies that is currently in existence (the opposite of extinct).
Extant speciesA species that is currently in existence (the opposite of extinct).
EXTENDED BINARY CODED DECIMAL INTERCHANGE CODEA binary code representing each letter, number, or other symbol with a unique 8-bit code. See also CODE (1).
Extended CookoutControl technique that reduces the amount of unreacted ethylene oxide (EO) and/or propylene oxide (PO)...
Extended One-Generation Reproductive StudyA redesign of the reproduction toxicity study commonly used to evaluate potential adverse effects of chemical...
Extended Reporting PeriodLengthens the period in which a claim may be made against the insured and reported to the insurer, however...
Extensible Markup Language1. A markup language for documents containing structured information. The XML specification defines a...
Extensive GardenExtensive gardens have thinner soil depths and require less management and less structural support than...
Extensive resourceA resource covering a large area that is not ecologically integrated and is not a collection of natural...
Extensively Drug Resistance ProcessResistance to nearly all known drugs, particularly the most efficacious or non-first line drugs, used in the...
extentThe amount and distribution of a resource, which may be measured in terms of spatial area, volume, depth, or...
Exterior Base Coating OperationSystem on each beverage can surface coating line used to apply a coating to the exterior of a two-piece...
Exterior CoatingArchitectural coating formulated and recommended for use in conditions exposed to the weather.
Exterior PrimerFirst layer and any subsequent layers of identically formulated coating applied to the exterior surface of an...
External CombustionFired combustion in which the flame and products of combustion are separated from contact with the process...
External Combustion EquipmentMay include fired heaters, industrial boilers, and commercial and domestic combustion units.
External CommunicationsCommunication to parties or organizations external to the physical site boundaries of the facilities and...
External Developer ResourceA resource or group of resources from an external institution that is not an Agency partner (state, tribe).
External EarThe outer part of the hearing system of the body. It includes the shell-like ear auricle which collects...
External EvaluationCollection, analysis, and interpretation of data conducted by an individual or organization outside of the...
External Floating Roof1. Pontoon-type or double-deck type cover that rests on the liquid surface in a storage tank or waste...
External Floating Roof FailureDefined as any time the external floating roof's primary seal has holes, tears, or other openings in the...
External Kelvin WaveSurface gravity wave with a rotational component propagated along the sea surface against a vertical barrier...
External Stakeholder1. Those individuals or groups, who are designated as an Interested Party, but function external to the...
External Standard1. A known amount of analyte that is analyzed separately from samples as part of a set of calibration...
External Validity1. The extent to which a finding applies (or can be generalized) to persons, objects, settings, or times...
External Validity ThreatsFactors that may reduce the transferability of a program's findings to other groups or jurisdictions.
External-Facing Online SiteA site that allows stakeholders to, for example, create communities, state problems, define goals and...
ExternalitiesEffects of a program that impose costs on persons or groups who are not targets.
Externality1. A consequence of an economic activity that is experienced by unrelated third parties. An externality can...
Extinct Animal Species1. When its race has not been seen in the wild for over fifty years, we say that it is extinct.
Extinct Plant Species1. When its race has not been seen in the wild for over fifty years, we say that it is extinct.
Extinct speciesA species that has disappeared from existence due to either natural or human-induced means.
extinctionThe disappearance of a species from part or all of its range.
Extra Risk1. A calculation of risk of adverse effects which adjusts for background incidence rates of the same effects...
Extra Risk (Dichotomous Model)[P(d)-P(0)]/[1 - P(0)], where P(d) is the risk at a dose = d and P(0) is the background risk at zero dose.
Extra Risk (Hill Model)1. The maximum (or minimum) achievable response is not 1, but is estimated from the model as Pmax (or Pmin).
Extracellular Matrix DegradationExtracellular Matrix Degradation consists of conjugation, transport, oxidation, and/or proteolysis of the...
Extract of Swinglea glutinosaA biofungicide for use on growing crops in agricultural, greenhouse, ornamental and turf use sites to control...
Extract, Transform, Loada category of software
Extractable Organic HalideOrganic compounds that contain halogen atoms such as chlorine. These organic compounds are semivolatile and...
Extraction and Mining WasteSoil and rock generated during the process of gaining access to the ore or mineral body, as well as water...
Extraction Batch1. A set of up to 20 field samples (not including QC samples) extracted together by the same person(s) during...
Extraction ProcedureDetermining toxicity by a procedure which simulates leaching; if a certain concentration of a toxic substance...
Extraction ProcessProcess operations that derive pharmaceutically active ingredients from natural sources such as plant roots...
Extraction SitePlace from which the dredged or fill material proposed for discharge is to be removed.
Extraction SolventOrganic chemical medium used to remove oil from an oilseed. Typically, the extraction solvent is a commercial...
extraction well1. A discharge well used to remove groundwater or air.
ExtractivesAny number of different compounds in biomass that are not an integral part of the cellular structure. The...
Extra-Label Drug UseAn antibiotic or other chemical used on the advice of a veterinarian in a dosage, route of administration...
Extralabel Drug UseDrug approved under the Federal Food, Drug and Cosmetic Act that is not used in accordance with the approved...
Extramural Agreement1. A legal agreement between EPA and an organization outside EPA for items or Services to be provided. Such...
Extramural Research1. Research supported by EPA through a grant, contract, or cooperative agreement.
Extranet1. An extranet is a private network that uses the Internet protocols and the public telecommunication system...
Extraordinary CircumstancesThose circumstances that may cause a significant environmental effect such that a proposed action that...
Extrapolation1. Extrapolation is a process that uses assumptions about fundamental causes underlying the observed...
Extrapolation, low doseAn estimate of the response at a point below the range of the experimental data, generally through the use of...
ExtrarespiratoryRefers to effects peripheral to the respiratory system as the portal of entry, or systemic effects.
Extratropical CycloneA cyclone in the middle and high latitudes often being 2000 kilometers in diameter and usually containing a...
extratropical storm1. A cyclonic weather system, occuring in the middle or high latitudes (e.g., poleward of the tropics) that...
Extravasation1. The leakage of body fluid or cells from the vascular system to the surrounding tissues. This process...
Extreme ColdEpisodic temperature decrease (not average temperatures).
Extreme Fire Behavior"Extreme" implies a level of fire behavior characteristics that ordinarily precludes methods of direct...
Extreme Heat1. Episodic temperature increase (not average temperatures).
Extreme High Durability CoatingAir dry coating, including a fluoropolymer-based coating, that is formulated and recommended for touchup of...
Extreme PrecipitationAn episode of abnormally high rain or snow. The definition of "extreme" is a statistical concept that varies...
Extreme Storm EventA storm event that has sufficient intensity to cause loss of life, injuries, significant property damage...
Extremely Hazardous Substance1. Under EPA regulations under EPCRA Section 302, extremely hazardous substances (EHSs) are 366 CERCLA...
Extremely Hazardous Substances1. Any of 406 chemicals identified by EPA as toxic, and listed under SARA Title III. The list is subject to...
ExtremityA body region referring to an upper or lower extremity.
ExtremophileMicroorganism that lives at extreme levels of pH, temperature, pressure or salinity.
Extrinsic Allergic AlveolitisConditions in which inhalation of organic dusts results in hypersensitivity reactions at the alveolar level...
Extrinsic SemiconductorProduct of doping a pure semiconductor. .
Extruding UnitUnit operation which converts polymer into a different shape by melting or mixing the polymer and then...
Extrusion1. A manufacturing process which creates articles with a fixed cross-sectional profile by pushing material...
Extrusion Die CleaningProcess by which the steel dies used in extrusion of aluminum are cleaned. The term includes a dip into a...
Extrusion Heat TreatmentSpray application of water to a workpiece immediately following extrusions for the purpose of heat treatment.
ExudateSubstance gradually discharged or secreted across intact cellular membranes or cell walls and present in the...
Exudative EpidermitisAn acute, generalized dermatitis that occurs in young pigs. The causal agent is Staphylococcus hyicus and is...
ExuviumThe remaining integument after ecdysis.
EXX GasolineGasoline-ethanol blend above E15 where XX equals the maximum volume percent ethanol in the gasoline-ethanol...
EyeThe organ of sight or vision.
Eye Anterior ChamberThe space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the...
Eye DisordersAny deviation from the normal structure or function of the eye that is manifested by a characteristic set of...
EyespotAny light-sensing structure in some primitive organisms that consists of a pigmented area and light sensitive...

1,815 of 30,736 terms in Environment terminology (MLC-0121). Request the full dataset.