User Guide to Thresholds and Classification - Environmental ...

307User Guide for Thresholds and ClassificationsAppendix 19C: Comparison of European Union aquatic riskphrases with Hazardous Substances and New Organisms Act1996 aquatic classificationsThe European Union (EC, 1967) risk phrases are converted into the equivalent Hazardous Substances andNew Organisms Act 1996 (HSNO Act) classification in Table 19C.1.Table 19C.1: Comparison of European Union (EU) aquatic risk phrases with HSNO Act aquatic classificationsEU risk phrasesR50 Very toxic to aquatic organismsFor substances with acute toxicity 1 mg/L 9.1AR50/53HSNO Act equivalentR51 Toxic to aquatic organismsFor substances with acute toxicity 1 mg/L < LC 5010 mg/LR51 alone: 9.1D unless there is no data toindicate the substance is rapidly degradableor not bioaccumulative in which case 9.1BappliesR51/R53 9.1BR52 Harmful to aquatic organismsFor substances with acute toxicity 10 mg/L < LC 50100 mg/L9.1D unless there is no data to indicate thesubstance is rapidly degradable or notbioaccumulative in which case 9.1C appliesR52/53 9.1CR53 May cause long-term adverse effects in aquatic environmentSubstances not falling under the criteria listed above, but which, onthe basis of the available evidence concerning their persistence,potential to accumulate, and predicted or observed environmentalfate and behaviour may nevertheless present a long-term and/ordelayed danger to the structure and/or functioning of aquaticecosystems. For example, poor water-soluble substances(solubility of less than 1 mg/L) if:9.1D clause cthey are not readily degradable; andthe log P OW100).3.0 (unless the experimentally determined BCF isNotesa. BCF = bioconcentration factor; LC 50 = median lethal dose; P OW = Kow the octanol/water partition co-efficient.b. The EU classification criteria for bioconcentration potential and biodegradation are more conservative than theHSNO Act criteria for these properties, so may result in a more precautionary HSNO Act aquatic hazardclassification than might otherwise be the case under the EU system.Source: EC (1967).January 2012 EPA0109