User Guide to Thresholds and Classification - Environmental ...

25User Guide for Thresholds and Classificationsii.iii.iv.(A failure to undergo a transition from deflagration to detonation when tested in any one of thethree type 5(b) tests, prescribed in section 15.5, pp 136–144, of the UN Manual of Tests andCriteria.A transition from deflagration to detonation is considered to have occurred in a type 5(b)(i)(French DDT test) if the criteria in para 15.5.1.4 of the UN Manual of Tests and Criteria are met.These criteria are:the lead witness plate is compressed in a manner characteristic of detonation; andthe measured propagation velocity is greater than the speed of sound in the substance andconstant in the part of the test tube furthest from the initiator.A transition from deflagration to detonation is considered to have occurred in a type 5(b)(ii) (USADDT test) if the criteria in para 15.5.2.4 of the UN Manual of Tests and Criteria are met. In thiscase, the test result is considered positive if a hole is punched through the witness plate.v. A transition from deflagration to detonation is considered to have occurred in a type 5(b)(iii)(deflagration to detonation transition test) if the criteria in para 15.5.3.4 of the UN Manual of Testsand Criteria are met. In this case, test results are assessed by the tube rupture character orexplosion of the detonating cord. The result is considered positive if the tube fragments.)(vi) A lack of an intense crack or projection of fragments from the fire area when a pile of packages ofthe explosive substance is tested in the prescribed external fire test type 5(c), as prescribed insection 15.6, pp 145–146, UN Manual of Tests and Criteria. (The test criteria are in paras15.6.1.3.5 and 15.6.1.4 of the UN Manual of Tests and Criteria.)Note that if a substance gives a positive result in any of the Test Series 5 tests discussed above,then the substance should not be classified in subclass 1.5, but should be tested and classifiedaccording to Test Series 6.f. Subclass 1.6 – extremely insensitive articles that do not have a mass explosion hazardArticles that contain only extremely insensitive detonating substances and that demonstrate anegligible probability of accidental initiation or propagation. This is evidenced by the following.i. In the case of explosive substances, a failure to give a positive response to any of the first sixtests of Test Series 7 (test types 7(a)–(f)) for sensitivity to shock, impact, external fire, andelevated temperature, as prescribed in section 17, pp 159–175, of the UN Manual of Tests andCriteria. (The test criteria are in paras 17.4.1.4, 17.5.1.4, 17.6.1.4, 17.6.2.4, 17.7.1.4, 17.7.2.4,17.8.1.4, and 17.9.1.4 of the UN Manual of Tests and Criteria.).ii. In the case of explosive articles containing extremely insensitive detonating substances, a failureto give a positive response to any of the last four tests of Test Series 7 (test types 7(g), 7(h), 7(j),and 7(k)) for sensitiveness to external fire, elevated temperature, impact, and detonation of anadjacent article, as prescribed in section 17, pp 176–179, of the UN Manual of Tests and Criteria.(The test criteria are in paras 17.10.1.4, 17.11.1.4, 17.12.1.4, and 17.13.1.4 respectively of theUN Manual of Tests and Criteria.)January 2012 EPA0109