User Guide to Thresholds and Classification - Environmental ...

45User Guide for Thresholds and Classifications5. Flammable Liquids and Liquid Desensitised Explosives –Subclasses 3.1 and 3.25.1. Flammable liquids – subclass 3.1Subclass 3.1 is equivalent to class 3 of the UN Model Regulations (United Nations, 1999b).Key terms are defined in section 3.2 in chapter 3.5.1.1. Threshold criteria for flammable liquidsAny liquid that gives off a vapour that ignites at a temperature of less than or equal to 93°C in a closed cupflashpoint test is considered to be a flammable substance within the meaning of the Hazardous Substancesand New Organisms Act 1996 (HSNO Act).ExamplesXylene has a flashpoint of 28°C, so is a flammable liquid.Ethylene glycol has a flashpoint of 111°C, so is not classified as a flammable liquid.5.1.2. Classification of flammable liquidsThe classification category for flammable liquids is determined in accordance with the following criteria.Category A (very high hazard) – classification 3.1A (equivalent to United Nations Packing Group (UNPG) I)Any liquid that gives off a flammable vapour that ignites in a closed cup flashpoint test at a temperatureless than 23°C, and has an initial boiling point (IBP) of less than or equal to 35°C.Category B (high hazard) – classification 3.1B (equivalent to UN PG II)Any liquid that gives off a flammable vapour that ignites in a closed cup flashpoint test at a temperatureless than 23°C, but has an initial boiling point (IBP) greater than 35°C.Category C (medium hazard) – classification 3.1C (equivalent to UN PG III)Any liquid that gives off a flammable vapour that ignites in a closed cup flashpoint test at a temperaturegreater than or equal to 23°C, but less than or equal to 60°C.Category D (low hazard) – classification 3.1DAny liquid that gives off a flammable vapour that ignites in a closed cup flashpoint test at a temperaturegreater than 60°C but less than or equal to 93°C.5.1.3. DiscussionThese classification categories are equivalent to the recommendations from the United Nations Committeeof Experts on the Transport of Dangerous Goods (UNCETDG), noting that category D is as proposed by theUNCETDG subcommittee advising the Inter-Organisation Programme on the Sound Management ofChemicals (IOMC) on flammability.January 2012 EPA0109