Toxic unit definition

Toxic unit means a measure of acute or chronic toxicity in an effluent. One acute toxic unit (TUa) is the reciprocal of the effluent concentration that causes 50 percent effect or mortality to organisms for acute exposures (100/LC50); one chronic toxic unit (TUc) is the reciprocal of the effluent concentration that causes no observable adverse effect level on test organisms for chronic exposures (100/NOAEL).
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Toxic unit means a measure of acute or chronic toxicity in an effluent. One
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Examples of Toxic unit in a sentence

  • Toxic unit models, which are a specialized case of concentration addition, have been applied to the assessment of the toxicity of PAH mixtures in sediment (Swartz et al., 1995; Di Toro et al., 2000; Lee et al., 2001), but they are unlikely to be applicable to complex mixtures of contaminants commonly found in the environment that have different modes of toxic action.

  • Toxic unit acute (TUa) is the reciprocal of the effluent concentration that causes 50 percent of the organisms to die by the end of the acute exposure period.

  • Toxic unit equivalents also were computed for pyrethroid pesticides in sediment, based on available literature LC50 values (LC50 is the concentration of a chemical which is lethal on average to 50 percent of test organisms).

  • For Outfall 012, chronic toxicity occurs when, during a chronic toxicity test, the TUc is greater than 1.6. Toxic unit chronic (TUc) is the reciprocal of the effluent concentration that causes no observable effect on the test organisms by the end of the chronic exposure period and is calculated as 100/LC25.

  • For Outfall 012, chronic toxicity occurs when, during a chronic toxicity test, the TUc greater than 1.6. Toxic unit chronic (TUc) is the reciprocal of the effluent concentration that causes no observable effect on the test organisms by the end of the chronic exposure period and is calculated as 100/LC25.

  • Toxic unit 0.3-3.0 (slightly harmful): should be completed with field test.

  • If the all phases of the method are used, then the progress is chronological.

  • It was concluded that mixture risk assessment may be organised in a tiered fashion, consisting of the three major tiers PEC/PNEC summation, Toxic unit summation and Mixture testing.

  • Toxic unit chronic (TUc) is the reciprocal of the effluent concentration that causes no observable effect on the test organisms by the end of the chronic exposure period.

  • According to Sprogue and Ramsay (1965), toxic unit was calculated as: Toxic unit = actual concentration in solution / lethal threshold concentration.

Related to Toxic unit

  • Toxic Substance includes but is not limited to asbestos, polychlorinated biphenyls (PCBs) and lead-based paints.

  • Toxic chemical means a chemical or chemical category listed in 40 CFR 372.65.

  • toxic substances as defined by the Toxic Substances Control Act, as amended from time to time (“TSCA”), (4) “hazardous materials” as defined by the Hazardous Materials Transportation Act, as amended from time to time (“HMTA”), (5) asbestos, oil or other petroleum products, radioactive materials, urea formaldehyde foam insulation, radon gas and transformers or other equipment that contains dielectric fluid containing polychlorinated biphenyls and (6) any substance whose presence is detrimental or hazardous to health or the environment, including, without limitation, microbial or fungal matter or mold, or is otherwise regulated by federal, state and local environmental laws (including, without limitation, RCRA, CERCLA, TSCA, HMTA), rules, regulations and orders, regulating, relating to or imposing liability or standards of conduct concerning any Hazardous Materials or environmental, health or safety compliance (collectively, “Environmental Requirements”). As used in this Contract: “Release” means spilling, leaking, pumping, pouring, emitting, emptying, discharging, injecting, escaping, leaching, dumping or disposing.

  • Toxic pollutant contaminant", "restricted hazardous waste", "infectious waste", "toxic substances", or any other term or expression intended to define, list or classify substances by reason of properties harmful to health, safety or the indoor or outdoor environment (including harmful properties such as ignitability, corrosivity, reactivity, carcinogenicity, toxicity, reproductive toxicity, "TCLP toxicity" or "EP toxicity" or words of similar import under any applicable Environmental Laws); (ii) any oil, petroleum, petroleum fraction or petroleum derived substance; (iii) any drilling fluids, produced waters and other wastes associated with the exploration, development or production of crude oil, natural gas or geothermal resources; (iv) any flammable substances or explosives; (v) any radioactive materials; (vi) any asbestos-containing materials; (vii) urea formaldehyde foam insulation; (viii) electrical equipment which contains any oil or dielectric fluid containing polychlorinated biphenyls; (ix) pesticides; and (x) any other chemical, material or substance, exposure to which is prohibited, limited or regulated by any governmental authority or which may or could pose a hazard to the health and safety of the owners, occupants or any Persons in the vicinity of any Facility or to the indoor or outdoor environment.

  • Hazardous Wastes means all waste materials subject to regulation under CERCLA, RCRA or applicable state law, and any other applicable Federal and state laws now in force or hereafter enacted relating to hazardous waste disposal.

  • Pollutant means any dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, refuse, oil, grease, sewage sludge, munitions, chemical wastes, biological materials, medical wastes, radioactive substance (except those regulated under the Atomic Energy Act of 1954, as amended (42 U.S.C. §§ 2011 et seq.)), thermal waste, wrecked or discarded equipment, rock, sand, cellar dirt, industrial, municipal, agricultural, and construction waste or runoff, or other residue discharged directly or indirectly to the land, ground waters or surface waters of the State, or to a domestic treatment works. “Pollutant” includes both hazardous and nonhazardous pollutants.

  • Regulated NSR pollutant means the following:

  • Hazardous Waste means the substances regulated as such pursuant to any Environmental Law.

  • Household Hazardous Waste means any waste material derived from households (including single

  • toxic a “pollutant”, a “contaminant”, or words of similar meaning and regulatory effect pursuant to any Environmental Law and also including any petroleum product or by-product, asbestos-containing material, lead-containing paint, mold, polychlorinated biphenyls or radioactive materials.

  • Gaseous pollutants means the exhaust gas emissions of carbon monoxide, oxides of nitrogen expressed in nitrogen dioxide (NO2) equivalent and hydrocarbons assuming ratio of:

  • Contaminant means any waste, pollutant, hazardous substance, toxic substance, hazardous waste, special waste, petroleum or petroleum-derived substance or waste, asbestos in any form or condition, polychlorinated biphenyls (“PCBs”), or any constituent of any such substance or waste.

  • Radioactive waste means any waste which contains radioactive material in concentrations which exceed those listed in 10 CFR Part 20, Appendix B, Table II, Column 2.

  • Irritant means any substance, other than a corrosive, that on

  • chemical tanker means a ship constructed or adapted and used for the carriage in bulk of any liquid product listed in chapter 17 of the International Bulk Chemical Code;

  • Natural radioactivity means radioactivity of naturally occurring nuclides.

  • Industrial wastes means the liquid wastes from industrial manufacturing processes, trade, or business as distinct from sanitary sewage.

  • Infectious waste means a solid waste that contains or may reasonably be

  • Hazardous Air Pollutant (HAP means any pollutant listed by the EPA as a hazardous air pollutant in conformance with Section 112(b) of the Clean Air Act. A list of these pollutants is available at the Division of Air Quality.

  • Hazardous Waste Management Facility means, as defined in NCGS 130A, Article 9, a facility for the collection, storage, processing, treatment, recycling, recovery, or disposal of hazardous waste.

  • Restricted use pesticide means any pesticide or device which, when used as directed or in accordance with a widespread and commonly recognized practice, the director determines, subsequent to a hearing, requires additional restrictions for that use to prevent unreasonable adverse effects on the environment including people, lands, beneficial insects, animals, crops, and wildlife, other than pests.

  • Hazardous chemical has the meaning given in subregulation 5(1) of the Work Health and Safety Regulations 2011 (Cth) and includes: prohibited carcinogen, as defined in subregulation 5(1) of the Work Health and Safety Regulations 2011 (Cth); restricted carcinogen, as defined in subregulation 5(1) of the Work Health and Safety Regulations 2011 (Cth); hazardous chemicals the use of which is restricted under regulation 382 of the Work Health and Safety Regulations 2011 (Cth), including polychlorinated biphenyls; Schedule 11 Hazardous Chemicals; hazardous chemicals listed in Table 14.1 of Schedule 14 of the Work Health and Safety Regulations 2011 (Cth); Schedule 15 Chemicals; and lead as defined in subregulation 5(1) of the Work Health and Safety Regulations 2011 (Cth).

  • Hazardous air pollutant means any air pollutant listed as a hazardous air pollutant pursuant to Section 112(b) of the FCAA.

  • Air pollutant , which means any solid, liquid or gaseous substance (including noise) present in the atmosphere in such concentration as may be or tend to be injurious to human beings or other living creatures or plants or property or environment.