User Guide to Thresholds and Classification - Environmental ...

426User Guide for Thresholds and Classifications1 µg/L × 10 µL/bee = 10 µg/beeThis approach is valid only if:the average amount of diet consumed per bee is directly measured in the test;the average amount of diet can be predicted due to the feed being restricted to the quantity readilyconsumed within the exposure period (4 h for SETAC) test; andthere are no obvious reductions in food palatability.22.1.2. MetabolitesThe substances may be transformed in the environment by abiotic or biotic processes. The potential hazardsthat these metabolites pose to terrestrial organisms must be evaluated when classifying the parentsubstance. An in-depth discussion of the classification of metabolites is in chapter 18.22.2. Terrestrial invertebrate hazard threshold and classification criteria22.2.1. Terrestrial invertebrate hazard threshold criteriaSchedule 6 to the Hazardous Substances (Minimum Degrees of Hazard) Regulations 2001 states:2 Minimum degrees of hazard(1) A substance with ecotoxic properties is not hazardous for the purposes of the Act unless—…(d) the substance is ecotoxic to terrestrial invertebrates because data for the substance indicates anacute oral or contact LD 50 of 25 micrograms or less of the substance per terrestrial invertebrate, as aresult of exposure to the substance.If data for the substance meet the above criteria, then the substance needs to be assigned a terrestrialinvertebrate classification.22.2.2. ClassificationSchedule 6 to the Hazardous Substances (Classification) Regulations 2001 specifies three classificationcategories for substances that are ecotoxic to terrestrial invertebrates (subclass 9.4).A subclass 9.4 classification and the subsequent category apply to any substance that meets the followingcriteria.Category 9.4A – substances that are very ecotoxic to terrestrial invertebrates:A substance for which data indicate a contact or an oral LD 50 < 2 micrograms of substance per terrestrialinvertebrate.Category 9.4B – substances that are ecotoxic to terrestrial invertebrates:A substance for which data indicate a contact or an oral LD 50 ≥ 2 but < 11 micrograms of substance perterrestrial invertebrate.January 2012 EPA0109