Laboratory Terms

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

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Radiation: Transmission of energy though space or any medium. Also known as radiant energy.
Radiation Standards: Regulations that set maximum exposure limits for protection of the public fro...
Radio Frequency Radiation: non-ionizing electromagnetic radiation.)
Radioactive Decay: Spontaneous change in an atom by emission of of charged particles and/or gamm...
Radioactive Substances: Substances that emit ionizing radiation.
Radioactive Waste: Any waste that emits energy as rays, waves, streams or energetic particles. R...
Radioisotopes: Chemical variants of radioactive elements with potentially oncogenic, teratog...
Radionuclide: Radioactive particle, man-made (anthropogenic) or natural, with a distinct at...
Radius of Influence: 1. The radial distance from the center of a wellbore to the point where there...
Radius of Vulnerability Zone: The maximum distance from the point of release of a hazardous substance in wh...
Radon: A colorless naturally occurring, radioactive, inert gas formed by radioactive...
Radon Daughters: Short-lived radioactive decay products of radon that decay into longer-lived ...
Radon Decay Products: A term used to refer collectively to the immediate products of the radon deca...
Rainbow Report: Comprehensive document giving the status of all pesticides now or ever in reg...
Rasp: A machine that grinds waste into a manageable material and helps prevent odor.
Raw Agricultural Commodity: An unprocessed human food or animal feed crop (e.g., raw carrots, apples, cor...
Raw Sewage: Untreated wastewater and its contents.
Raw Water: Intake water prior to any treatment or use.
Re-entry: (In indoor air program) Refers to air exhausted from a building that is immed...
Reactivity: Refers to those hazardous wastes that are normally unstable and readily under...
Reaeration: Introduction of air into the lower layers of a reservoir. As the air bubbles ...
Real-Time Monitoring: Monitoring and measuring environmental developments with technology and commu...
Reasonable Further Progress: Annual incremental reductions in air pollutant emissions as reflected in a St...
Reasonable Maximum Exposure: The maximum exposure reasonably expected to occur in a population.
Reasonable Worst Case: An estimate of the individual dose, exposure, or risk level received by an in...
Reasonably Available Control Measures RACM: A broadly defined term referring to technological and other measures for poll...
Reasonably Available Control Technology RACT: Control technology that is reasonably available, and both technologically and...
Recarbonization: Process in which carbon dioxide is bubbled into water being treated to lower ...
Receiving Waters: A river, lake, ocean, stream or other watercourse into which wastewater or tr...
Receptor: Ecological entity exposed to a stressor.
Recharge: The process by which water is added to a zone of saturation, usually by perco...
Recharge Area: A land area in which water reaches the zone of saturation from surface infilt...
Recharge Rate: The quantity of water per unit of time that replenishes or refills an aquifer.
Reclamation: (In recycling) Restoration of materials found in the waste stream to a benefi...
Recombinant Bacteria: A microorganism whose genetic makeup has been altered by deliberate introduct...
Recombinant DNA: The new DNA that is formed by combining pieces of DNA from different organism...
Recommended Maximum Contaminant Level RMCL: The maximum level of a contaminant in drinking water at which no known or ant...
Reconstructed Source: Facility in which components are replaced to such an extent that the fixed ca...
Reconstruction of Dose: Estimating exposure after it has occurred by using evidence within an organis...
Record of Decision ROD: A public document that explains which cleanup alternative(s) will be used at ...
Recovery Rate: Percentage of usable recycled materials that have been removed from the total...
Recycle: Minimizing waste generation by recovering and reprocessing usable products th...
Recycling and Reuse Business Assistance Centers: Located in state solid-waste or economic-development agencies, these centers ...
Recycling Economic Development Advocates: Individuals hired by state or tribal economic development offices to focus fi...
Recycling Mill: Facility where recovered materials are remanufactured into new products.
Recycling Technical Assistance Partnership National Network: A national information-sharing resource designed to help businesses and manuf...
Red Border: An EPA document undergoing review before being submitted for final management...
Red Tide: A proliferation of a marine plankton toxic and often fatal to fish, perhaps s...
Redemption Program: Program in which consumers are monetarily compensated for the collection of r...
Reduction: The addition of hydrogen, removal of oxygen, or addition of electrons to an e...
Reductive Precipitation: This procedure incorporates a chemical separation to remove interfering matri...
Reentry Interval: The period of time immediately following the application of a pesticide durin...
Reference Dose RfD: The RfD is a numerical estimate of a daily oral exposure to the human populat...
Reformulated Gasoline: Gasoline with a different composition from conventional gasoline (e.g., lower...
Refueling Emissions: Emissions released during vehicle re-fueling.
Refuse Reclamation: Conversion of solid waste into useful products; e.g., composting organic wast...
Regeneration: Manipulation of cells to cause them to develop into whole plants.
Regional Response Team RRT: Representatives of federal, local, and state agencies who may assist in coord...
Registrant: Any manufacturer or formulator who obtains registration for a pesticide activ...
Registration: Formal listing with EPA of a new pesticide before it can be sold or distribut...
Registration Standards: Published documents which include summary reviews of the data available on a ...
Regulated Asbestos-Containing Material RACM: Friable asbestos material or nonfriable ACM that will be or has been subjecte...
Regulated Medical Waste: Under the Medical Waste Tracking Act of 1988, any solid waste generated in th...
Relative Ecological Sustainability: Ability of an ecosystem to maintain relative ecological integrity indefinitely.
Relative Permeability: The permeability of a rock to gas, NAIL, or water, when any two or more are p...
Relative Risk Assessment: Estimating the risks associated with different stressors or management actions.
Release: Any spilling, leaking, pumping, pouring, emitting, emptying, discharging, inj...
Remedial Action RA: The actual construction or implementation phase of a Superfund site cleanup t...
Remedial Design: A phase of remedial action that follows the remedial investigation/feasibilit...
Remedial Investigation: An in-depth study designed to gather data needed to determine the nature and ...
Remedial Project Manager RPM: The EPA or state official responsible for overseeing on-site remedial action.
Remedial Response: Long-term action that stops or substantially reduces a release or threat of a...
Remediation: 1. Cleanup or other methods used to remove or contain a toxic spill or hazard...
Remote Sensing: The collection and interpretation of information about an object without phys...
Removal Action: Short-term immediate actions taken to address releases of hazardous substance...
Renewable Energy Production Incentive REPI: Incentive established by the Energy Policy Act available to renewable energy ...
Repeat Compliance Period: Any subsequent compliance period after the initial one.
Reportable Quantity RQ: Quantity of a hazardous substance that triggers reports under CERCLA. If a su...
Repowering: Rebuilding and replacing major components of a power plant instead of buildin...
Representative Sample: A portion of material or water that is as nearly identical in content and con...
Reregistration: The reevaluation and relicensing of existing pesticides originally registered...
Reserve Capacity: Extra treatment capacity built into solid waste and wastewater treatment plan...
Reservoir: Any natural or artificial holding area used to store, regulate, or control wa...
Residential Use: Pesticide application in and around houses, office buildings, apartment build...
Residential Waste: Waste generated in single and multi-family homes, including newspapers, cloth...
Residual: Amount of a pollutant remaining in the environment after a natural or technol...
Residual Risk: The extent of health risk from air pollutants remaining after application of ...
Residual Saturation: Saturation level below which fluid drainage will not occur.
Residue: The dry solids remaining after the evaporation of a sample of water or sludge.
Resistance: For plants and animals, the ability to withstand poor environmental condition...
Resource Recovery: The process of obtaining matter or energy from materials formerly discarded.
Response Action: 1. Generic term for actions taken in response to actual or potential health-t...
Responsiveness Summary: A summary of oral and/or written public comments received by EPA during a com...
Restoration: Measures taken to return a site to pre-violation conditions.
Restricted Entry Interval: The time after a pesticide application during which entry into the treated ar...
Restricted Use: A pesticide may be classified (under FIFRA regulations) for restricted use if...
Restriction Enzymes: Enzymes that recognize specific regions of a long DNA molecule and cut it at ...
Retrofit: Addition of a pollution control device on an existing facility without making...
Reuse: Using a product or component of municipal solid waste in its original form mo...
Reverse Osmosis: A treatment process used in water systems by adding pressure to force water t...
Reversible Effect: An effect which is not permanent; especially adverse effects which diminish w...
Ribonucleic Acid RNA: A molecule that carries the genetic message from DNA to a cellular protein-pr...
Rigid Porous Polyethylene RPP: Rigid Porous Polyethylene samplers, or RPPs, are made of thin sheets of foam-...
Rill: A small channel eroded into the soil by surface runoff; can be easily smoothe...
Ringlemann Chart: A series of shaded illustrations used to measure the opacity of air pollution...
Riparian Habitat: Areas adjacent to rivers and streams with a differing density, diversity, and...
Riparian Rights: Entitlement of a land owner to certain uses of water on or bordering the prop...
Risk: A measure of the probability that damage to life, health, property, and/or th...
Risk Assessment: Qualitative and quantitative evaluation of the risk posed to human health and...
Risk Characterization: The last phase of the risk assessment process that estimates the potential fo...
Risk Communication: The exchange of information about health or environmental risks among risk as...
Risk Estimate: A description of the probability that organisms exposed to a specific dose of...
Risk Factor: Characteristics (e.g., race, sex, age, obesity) or variables (e.g., smoking, ...
Risk for Endangered Species: Risk to aquatic species if anticipated pesticide residue levels equal one-fif...
Risk for Non-Endangered Species: Risk to species if anticipated pesticide residue levels are equal to or great...
Risk Management: The process of evaluating and selecting alternative regulatory and non-regula...
Risk-based Targeting: The direction of resources to those areas that have been identified as having...
Risk-Specific Dose: The dose associated with a specified risk level.
River Basin: The land area drained by a river and its tributaries.
Rodenticide: A chemical or agent used to destroy rats or other rodent pests, or to prevent...
Rotary Kiln Incinerator: An incinerator with a rotating combustion chamber that keeps waste moving, th...
Rough Fish: Fish not prized for sport or eating, such as gar and suckers. Most are more t...
Route of Exposure: The avenue by which a chemical comes into contact with an organism, e.g., inh...
Rubbish: Solid waste, excluding food waste and ashes, from homes, institutions, and wo...
Run-Off: That part of precipitation, snow melt, or irrigation water that runs off the ...
Running Losses: Evaporation of motor vehicle fuel from the fuel tank while the vehicle is in ...

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