User Guide to Thresholds and Classification - Environmental ...

320User Guide for Thresholds and ClassificationsProperty Nature of difficulty Relevance for classificationOxidisableSubject to corrosion ortransformation (thisrefers to metals andmetal compounds)BiodegradableAdsorbingChelatingColoured.HydrophobicIonisedMulti-componentbreakdown products. Comparison ofdegradation half-lives to theexposure regimen used in testing.Achieving, maintaining andmeasuring exposure concentration.Toxicity of modified chemicalstructures or breakdown products.Comparison of degradation half-livesto the exposure regimen used intesting.Achieving, maintaining andmeasuring exposure concentration.Comparison of partitioning from thewater column half-lives to theexposure regimen used in testing.Maintaining exposureconcentrations. Toxicity ofbreakdown products. Comparison ofdegradation half-lives to theexposure regimen used in testing.Maintaining exposureconcentrations. Analysing exposure.Toxicity mitigation due to reducedavailability of test substance.Distinguishing chelated and nonchelatedfractions in media.Light attenuation (an algal problem).Maintaining constant exposureconcentrations.Maintaining exposureconcentrations. Toxicity ofbreakdown products. Comparison ofdegradation half-lives to theexposure regime used in testing.Preparing representative testbatches.and needs to address the toxicity of significantbreakdown products.Classification requires expert judgement,should be based on measured concentrations,and needs to address the toxicity of significantbreakdown products.Classification requires expert judgement,should be based on measured concentrations,and needs to address the toxicity of significantbreakdown products.Classification requires expert judgement,should be based on measured concentrations,and needs to address the toxicity of significantbreakdown products.Classification should use measuredconcentration of available materialClassification should use measurement ofconcentration of bioavailable material.Classification must distinguish toxic effectsfrom reduced growth due to light attenuationClassification should use measuredconcentration.Classification requires expert judgement,should be based on measured concentrations,and needs to address the toxicity of significantbreakdown products.Considered same as complex mixture.January 2012 EPA0109