The division of class 2 and the subsidiary hazards depend on the nature of the contents of the aerosol dispenser. The following provisions shall apply:
.1 Class 2.1 applies if the contents include 85% by mass or more flammable
components and the chemical heat of combustion is 30 kJ/g or more;
.2 Class 2.2 applies if the contents contain 1% by mass or less flammable
components and the heat of combustion is less than 20 kJ/g.
.3 Otherwise the product shall be classified as tested by the tests described
in the Manual of Tests and Criteria, part III, section 31.
Extremely flammable and flammable aerosols shall be classified in class
2.1; non-flammable in class 2.2;
.4 Gases of class 2.3 shall not be used as a propellant in an aerosol
dispenser;
.5 Where the contents other than the propellant of aerosol dispensers to be
ejected are classified as class 6.1 packing groups II or III or class 8
packing groups II or III, the aerosol shall have a subsidiary hazard of
class 6.1 or class 8
.6 Aerosols with contents meeting the criteria for packing group I for
toxicity or corrosivity shall be prohibited from transport.
.7 Except for consignments transported in limited quantities (see chapter
3.4), packages containing aerosols shall bear labels for the primary risk
and for the subsidiary hazard(s), if any.
Flammable components are flammable liquids, flammable solids or flammable gases and gas mixtures as defined in Notes 1 to 3 of sub-section 31.1.3 of part III of the Manual of Tests and Criteria. This designation does not cover pyrophoric, self-heating or water-reactive substances. The chemical heat of combustion shall be determined by one of the following methods: ASTM D240, ISO/FDIS 13943: 1999 (E/F) 86.1 to 86.3 or NFPA 30B.