Hazardous Characteristics are the parameters identified by the USEPA that define a hazardous waste. They are Toxicity, Ignitability and Corrosivity. A fourth characteristic, reactivity, was withdrawn by the USEPA. However, several regulatory agencies continue to request the parameter. A positive test for any one characteristic defines the waste as hazardous.
Terms and Acronyms
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
Acceptable Risk – A recently developed concept in connection with toxic substances (insecticides, mercurials, carcinogens) food additives, air and water pollution, and related to environmental concerns. Possibly defined as a risk level at which a seriously adverse result is highly unlikely to occur but one cannot prove whether or not there is complete safety.
Accuracy – The degree with which the obtained result agrees with the actual results, often expressed as recovery. In mathematical terms accuracy is the average of the results from a repeated analysis of the same sample, compared to the actual amount of analyte in the sample. When applied to a set of observed values, accuracy will be a combination of a random component and of a common systematic error (or bias) component.
Acute Toxicity – The ability of a substance to cause severe biological harm or health soon after a single exposure or dose. Any poisonous effect resulting from a single short term exposure to a toxic substance.
Aerobic – A life or processes that require or are not destroyed by, the presence of oxygen.
Analyte – A compound or property that is to be determined and/ or analyzed.
Bioassay- A test to determine the relative strength of a substance by comparing its effect on a test organism to that of a standard preparation.
Biochemical Oxygen Demand BOD – A measure of the amount of oxygen consumed (measured as dissolved oxygen) in the biological processes that break down organic matter in water. The greater the BOD, the greater the degree of pollution.
BNA – Base, neutral and acid extractable compound. The term base, neutral and acid refer to the pH conditions of the sample during methylene chloride solvent extraction. Base/neutral compounds extract more efficiently from water under basic or elevated pH conditions in turn, acid extractable compounds are removed effectively under acid conditions.
Conductivity – Conductivity is a measurement of ions present in the water, their charge, mobility, valence and relative concentration. The presence on ions can be measured through a cell with fixed electrodes. In laboratory and field analysis of water, the “specific conductance” is an indicator of impurities in the sample. Clean or pure water is indicated by lower conductivity.
Equipment Blank – Sampling equipment is rinsed with reagent water that is tested to determine residual contaminating after cleaning. The rinsate is collected after equipment decontamination and prior to sampling. This blank is useful in documenting adequate decontamination of sampling equipment.
Field Duplicates – Two independent samples collected identically from the same sampling point at the same time. Analyzed as two separate samples taken from the same source, these duplicates are useful in documenting the precision of the sampling procedure.
Hardness – is a measure of the amount of dissolved calcium and magnesium in the water and generally reported as calcium carbonate (CaCO3). Hardness is an important consideration when choosing corrosion control methods.
Instrument Detection Limit (IDL) – The minimum signal level that can be differentiated from instrument background noise with 99% confidence.
Internal Standards – Compounds added to identified samples after sample preparation at a known concentration and prior to instrument analysis. Internal standards are used as a basis for qualitative and quantitative analysis of the target compounds.
Iron bacteria – Often found in stagnant water this harmless bacteria uses iron in its metabolic processes. Typically forms gelatinous deposits that are odiferous, cause disagreeable tastes and may clog pipes.
Laboratory Control Sample (LCS) – Known amounts of a target analyte added to reagent water for evaluation. This is used as a quality control measure to document laboratory sample preparation performance.
Matrix Spike (MS) – A concentration of a known target analyte added (spiking) to a sample and analyzed to determine recovery for the specific matrix. The spiking occurs prior to sample preparation and analysis. A matrix spike is used to document the bias of a method in a given sample matrix.
Matrix Spike Duplicate (MSD) – A duplicated matrix spike sample spiked with identical concentrations of target analyte(s). The spiking occurs prior to sample preparation and analysis. They are used to document the precision and bias of a method in a given sample matrix.
MBAS (surfactants or detergents) – Anionic surfactants that can be extracted into chlororform solution by a ion pairing mechanism with methylene blue. Surfactants or foaming agents enter waters and wastewaters mainly by discharge of aqueous wastes from household and industrial laundering and other cleansing operations.
Method Blank – An analyte-free matrix to which all reagents are added in the same volumes or proportions as used in the sample processing. The method blank should be carried through the complete sample preparation and analytical procedure. The method blank is used to document contamination resulting from the analytical process.
Method Detection Limit (MDL) – The minimum concentration of a target analyte that can be measured and reported with 99% confidence. Multiple analysis of the analyte at minimal concentration are used to statistically determine MDL limits of a sample in a given matrix type.
Nitrate – Expressed as (NO3) is compound containing nitrogen that can exist in the atmosphere or as a dissolved gas in water and which can have harmful effects on humans and animals. Nitrates in water can cause severe illness in infants and domestic animals. A plant nutrient and inorganic fertilizer, nitrate is found in septic systems, animal feed lots, agricultural fertilizers, manure, industrial waste waters, sanitary landfills, and garbage dumps.
PCBs – Polychlorinated biphenyls. One of several aromatic compounds containing two benzene nuclei with two or more substituent chlorine atoms. Because of their persistence, toxicity, and ecological damage via water pollution their manufacture was discontinued in the U.S. in 1976.
PCB Congeners – Chlorine-substituted biphenyl compounds. PCB stands for polychlorinated biphenyls, and any single, unique, well-defined chemical compound in the PCB category is called a congener. Individual congeners are identified by the number and position of the chlorine atoms around the biphenyl rings.
Percent Solids – The proportion of solid in a soil sample determined by drying an aliquot of the sample.
Perchlorate – both naturally occurring and man-made, it is typically found in the form of salts such as ammonium perchlorate, potassium perchlorate, sodium perchlorate and lithium perchlorate; it is extremely soluble in water, making it difficult to remove from water by conventional treatment processes; man-made perchlorate is most commonly used as the primary ingredient in solid rocket fuel; other uses are fireworks, road flares, munitions, air bag inflator charges and matches, and is also an impurity in chemical fertilizers and agricultural chemical compounds; the USEPA is still studying its prevalence, health effects and exposure pathways, so a federal drinking water standard has not been set.
Pesticides – A pesticide is any substance or mixture of substances used for preventing, destroying, repelling or mitigating a pest. The term pesticide refers to insecticides, herbicides, fungicides and various other substances used to control pests.
pH – pH is measured on a scale of 0-14. In general, water with a pH < 7 is considered acidic and with a pH > 7 is considered basic. Water with a low pH (< 6.5) could be acidic, soft, and corrosive. Water with a pH > 8.5 could indicate that the water is hard. A change of 1 unit on a pH scale represents a 10-fold change in pH.
Practical Quantitation Limit (PQL) – The lowest level that can be reliably achieved within specified limits of precision and accuracy during routine laboratory operating conditions.
Precision – The agreement among a set of replicate measurements without assumption of knowledge of the true value. Precision is estimated by means of duplicate / replicate analyses.
Sample Delivery Group (SDG) – A unit within a sample Case (or sampling event) that is used to identify a group of samples for delivery. An SDG is a group of 20 or fewer samples within a Case, received over a period of up to seven calendar days. Data from all samples in an SDG are due concurrently. A SDG is defined by one of the following, whichever occurs first:
- SDG: or
- Each 20 samples within a SDG: or
- Each seven-day calendar period, during which samples in a SDG are received, beginning with receipt of the first sample in the SDG.
Samples may be assigned to SDGs by matrix (i.e. all soils in one SDG, all waters in another), at the discretion of the laboratory.
Surrogate – An organic compound which is similar to the target analyte(s) in chemical composition and behavior in the analytical process, but which is not normally found in environmental samples.
Target Compounds – A specific list of compounds that are to be quantified in a sample. In such a case, the laboratory analyzes the sample for a standard list of potential compounds.
Tentatively Identified Compounds (TICs) – Compounds detected in samples that are not targeted compounds, internal standards, or surrogate standards. Up to 30 peaks (those greater than 10% of peak areas or heights of nearest internal standards) are subjected to mass spectral library searches for tentative identification.
Total Metals – Metallic elements that have been digested prior to analysis.
Trip Blank – A sample of analyte-free media taken from the laboratory to the sampling site, and returned to the laboratory unopened. A trip blank is used to document contamination attributable to shipping and field handling procedures. This type of blank is useful in documenting contamination of volatile organic samples.
Volatile Organic Compounds (VOC’s) –VOC’s include a wide variety of chemicals ranging from hydrocarbons found in crude oil, gasoline, paints, paint thinners and solvents to chlorine containing chemicals such as trichloroethylene (commonly used for removal of oily and greasy residues from metal products) and perchlorethylene (commonly used in dry cleaning operations)
Wet Chemistry – Refers to a number of procedures that involve distillations, colorimetric determinations and titrimetric measurements. Examples are chloride, nitrates, sulfates and biochemical oxygen demand.
Zinc – Zinc is an essential element in the diet. It is not considered very toxic to humans or other organisms. It is found naturally in many rock forming minerals; it also may be present in industrial discharges; It is used to galvanize steel, and is found in batteries, plastics, wood preservatives, antiseptics and in rat and mouse poison.