User Guide to Thresholds and Classification - Environmental ...

154User Guide for Thresholds and ClassificationsAppendix 10C: Globally Harmonized System of Classificationand Labelling of Chemicals acute toxicity hazard classificationThis appendix displays the toxicity categories from the Globally Harmonized System of Classification andLabelling of Chemicals (GHS) (United Nations, 2007) based on acute toxicity by the oral, dermal, andinhalation routes. (See Table 10C.1)The GHS acute toxicity categories are generally comparable with the acute toxicity categories in theHazardous Substances and New Organisms Act 1996 (HSNO Act) (see Table 10.1 and Table 10.2).However some of the key differences are as follows.The upper limit for gases under HSNO Act category 6.1D is 5,000 parts per million by volume (ppmV).Under the GHS, the upper limit for gases for category 4 (which is comparable to 6.1D) is 20,000 ppmV.The HSNO Act definition of dust and mist differs to that in the GHS.Table 10.1 has provided additional guidance as to when an acute inhalation toxicity classification should beassigned.Table 10C.1: Acute toxicity hazard categories and acute toxicity estimate values defining the respective categoriesExposure routeCategory 1HSNO Act6.1ACategory 2HSNO Act6.1BCategory 3HSNO Act6.1ECategory 4HSNO Act6.1DCategory 5HSNO Act6.1EOral (mg/kg bw) a 5 50 300 2,000Dermal LD 50 (mg/kg bw) a 50 200 1,000 2,000Gases (ppmV) a,b 100 500 2,500 20,000Vapours (mg/L) a,b,c,d 0.5 2.0 10 205000 fDusts and Mists(mg/L) a,b,e 0.05 0.5 1.0 5Notes: Gases concentration are expressed in ppm by volume (ppmV); LD 50 = median lethal dose; median lethalconcentration = LC 50; mg/kg bw = milligrams of the substance per kilogram of bodyweight; mg/L = milligrams of thesubstance per litreThe acute toxicity estimate (ATE) for the classification of a substance or ingredient in a mixture is derivedusing the:LD 50/LC 50 where available;appropriate conversion value from Table 10C.2 that relates to the results of a range test; orappropriate conversion value from Table 10C.2 that relates to a classification category;Inhalation cut-off values in the table are based on four-hour testing exposures. Conversion of existinginhalation toxicity data that has been generated according to one-hour exposures should be by dividing by afactor of 2 for gases and vapours and 4 for dusts and mists.January 2012 EPA0109