User Guide to Thresholds and Classification - Environmental ...

278User Guide for Thresholds and ClassificationsTermDefinitionThe lowest value expressed in milligrams of a substance per litre of water from:a. fish LC 50 data after a 96-hour exposure period; oracute aquatic ecotoxicity valueb. crustacean EC 50 data after a 48-hour exposure period; orc. algal, or other aquatic plant, EC 50 data after a 72-hour or 96-hour exposureperiod.See Schedule 6 to the Hazardous Substances (Classification) Regulations2001. See also LC 50, EC 50.BCFbioaccumulativeSee bioconcentration factor (BCF).Any substance that has a bioconcentration factor (BCF) greater than or equal to500 or, if BCF data are not available, a log K OW equal to or less than 4; and, forthe purposes of this definition, measured log K OW values take precedence overestimated values.See Schedule 6 to the Hazardous Substances (Minimum Degrees of Hazard)Regulations 2001. See also biconcentration factor (BCF), K OW.biocidal actionbioconcentration factor (BCF)BOD 5chemical oxygen demandchronic aquatic ecotoxicityvalueCODIn relation to a substance, means the substance causes mortality, inhibitedgrowth, or inhibited reproduction in an organism.See Schedule 6 to the Hazardous Substances (Minimum Degrees of Hazard)Regulations 2001.The steady state concentration of a substance in an aquatic organism dividedby the concentration of the substance in the surrounding water.See Schedule 6 to the Hazardous Substances (Minimum Degrees of Hazard)Regulations 2001.The five-day biochemical oxygen demand, being the mass of oxygen consumedby micro-organisms during oxidation of the substance in water over five days,expressed in milligrams of oxygen consumed per milligrams of the substance.See Schedule 6 to the Hazardous Substances (Minimum Degrees of Hazard)Regulations 2001.See COD.The lowest value expressed in milligrams of a substance per litre of water fromchronic fish, crustacean, algal, or other aquatic plant NOEC data.See Schedule 6 to the Hazardous Substances (Classification) Regulations2001. See also NOEC.The chemical oxygen demand, being the equivalent mass of oxygen from anoxidising agent, of a strength at least equal to the oxidising strength ofpotassium permanganate or potassium dichromate, that is consumed duringoxidation of the substance in water, expressed in milligrams of oxygenconsumed per milligram of the substance.See Schedule 6 to the Hazardous Substances (Minimum Degrees of Hazard)Regulations 2001.January 2012 EPA0109