User Guide to Thresholds and Classification - Environmental ...

53User Guide for Thresholds and ClassificationsThe Dangerous Goods Act 1974 groups class 4.1 flammable solids into categories A, B, and C, and listsspecific substances. The entries in these categories in the Schedule to the Dangerous Goods Act do notreadily correlate with UN division 4.1(a) or the HSNO Act classification subclasses 4.1.1, 4.1.2, and 4.1.3.Example substancesThe HSNO Act category A (equivalent to UN PG II) includes:hafnium powder, wetted;titanium powder, wetted;zirconium powder, wetted;aluminium powder, coated; andand ‗solids that cause fire through friction‘, listed above.The HSNO Act category B (equivalent to UN PG III) includes:sulphur;silicon powder (amorphous); and‗solids that cause fire through friction‘, listed above.6.2. Self-reactive flammable solids – subclass 4.1.26.2.1. Threshold criteria for self-reactive flammable solids subclass 4.1.2 (equivalent to UNdivision 4.1(b))A substance is considered a subclass 4.1.2 self-reactive flammable solid within the meaning of the HSNOAct when:a. in a quantity of 50 kg, it has a self-acceleration decomposition temperature (SADT) of less than or equalto 75ºC when tested in accordance with any of the test methods set out in Test Series H (section 28, pp279–300, UN Manual of Tests and Criteria), and it has a heat of decomposition greater than 300 J/g asrequired in para 2.4.2.3 of the UN Model Regulations; orb. it is a substance listed in para 2.4.2.3.2.3 of the UN Model Regulations as having a class and division of aself-reactive substance (UN division 4.1(b)).6.2.2. DiscussionNotes on thresholds for self-reactive flammable solidsThe HSNO Act threshold criteria for subclass 4.1.2 are equivalent to those for UN division 4.1(b) (includingType G) as set out in the UN Model Regulations (para 2.4.2.3).Test methodsFor any substance subjected to the threshold test method in (a) above, the result must be determined using:a. the finest particle form in which that substance is reasonably capable of being used or rendered; orJanuary 2012 EPA0109