User Guide to Thresholds and Classification - Environmental ...

158User Guide for Thresholds and ClassificationsAppendix 10D: Comparison of European Union acute toxicityrisk phrases with HSNO Act acute toxicity classificationsThe European Union (EC, 1967) risk phrases are converted into the equivalent Hazardous Substances andNew Organisms Act 1996 (HSNO Act) classification categories in Table 10D.1. Note that some cut-offvalues are not totally aligned with HSNO Act classification categories. This is noted in Table 10D.1 and forHSNO Act classification purposes a precautionary approach is advocated such that the higher hazardcategory is assigned.Table 10D.1: European Union risk phrases compared with HSNO Act acute toxicity classificationsEuropean Union risk phrasesHSNO ActequivalentcategoryVery Toxic (T+)A substance is determined to be hazardous and classified as Very Toxic (T+) and assignedone of the following risk phrases in accordance with the criteria given below.R26 Very toxic by inhalation6.1A6.1AAcute toxicity results:LC 50 inhalation, rat, for aerosols or particulates:L over 4 hours;LC 50 inhalation, rat, for gases and vapours:0.5 mg/L over 4 hours.6.1AR27 Very toxic in contact with skinAcute toxicity results: LD 50 dermal, rat or rabbit:50 mg/kg.6.1AR28 Very toxic if swallowedAcute toxicity results:LD 50 oral, rat: 25 mg/kg;less than 100% survival at 5 mg/kg oral, rat, by the fixed dose procedure.Toxic (T)A substance is determined to be hazardous and classified as Toxic (T) and assigned one ormore of the following risk phrase in accordance with the criteria given below.R23 Toxic by inhalationAcute toxicity results:LC 50 inhalation, rat, for aerosols or particulates: 0.25 < LC 50LC 50 inhalation, rat, for gases and vapours: 0.5 < LC 501 mg/L over 4 hours;2 mg/L over 4 hours.6.1ANote this cut-offcrosses into6.1B6.1B and 6.1C6.1B and 6.1C6.1BR24 Toxic in contact with skinAcute toxicity results: LD 50 dermal, rat or rabbit: 50 < LD 50400 mg/kg.6.1BNote this cut-offcrosses into6.1C.R25 Toxic if swallowed 6.1BJanuary 2012 EPA0109