User Guide to Thresholds and Classification - Environmental ...

43User Guide for Thresholds and ClassificationsRegulations 2001 to avoid any overlap with the Gas Act controls. This follows the previous practice asdefined in the Dangerous Goods (Class 2 – Gases) Regulations 1980, which stated in regulation 4:Nothing in these regulations shall apply to—(a) coal gas or natural gas except when packed, stored, conveyed or handled in cylinders ortransportable tanks.4.2. Flammable aerosols – subclass 2.1.24.2.1. Threshold criteria for flammable aerosolsAn aerosol is a flammable aerosol if it is a pressurised mixture containing a gas, compressed, liquefied, ordissolved under pressure, with or without a liquid, paste, or powder; comprising at least 45% by mass offlammable ingredients. The substance also must be packed under pressure in a way that is designed to bereleased as solid or liquid particles in suspension in a gas; or as a foam, paste, or powder; or in a liquidstate; or in a gaseous state.In this context, ‗flammable ingredient‘ means any substance that meets the threshold for a ‗flammable gas‘, a‗flammable liquid‘, a ‗flammable solid‘, or any combination of these.4.2.2. Classification of flammable aerosolsThe one classification category for flammable aerosols (2.1.2A) has the same threshold criteria as above.4.2.3. DiscussionThe UN Model Regulations definition of ‗aerosols‘ (chapter 3.3: notes 63 and 190) combines a description ofthe substance and a description of the package, as follows.A flammable aerosol is a substance that includes more than 45% by mass or more than 250 g of flammablecomponents, which are defined as ‗gases that are flammable in air at normal pressure, or are substances orpreparations that are in liquid form that have a flashpoint ≤ 100°C‘ (note 63).Aerosols, meaning the aerosol dispensers, are any non-refillable receptacles made of metal, glass, or plasticthat contain a gas compressed, liquefied, or dissolved under pressure, with or without a liquid, paste, orpowder, and fitted with a release device allowing the contents to be ejected as solid or liquid particles insuspension in a gas, as a foam, paste, or powder, in a liquid state, or in a gaseous state (note 190).Aerosols are classified under the UN Model Regulations as division 2.1 when the criteria of note 63 are met.The definitions of aerosol in European Commission Directive 75/324/EEC (EC, 1975) and the InternationalCivil Aviation Organization‘s Technical Instructions for Safe Transport of Dangerous Goods by Air (ICAO,2006) are virtually identical to the definition in the UN Model Regulations. The EC directive sets a maximumcapacity of metal aerosol dispensers of 1,000 ml. A recent amendment to the directive requires all aerosolswith any flammable contents to be considered flammable unless tests indicate that they are not.January 2012 EPA0109