# The Aerosol Dispensers Regulations 2009, Paragraph 1.10: Chemical Heat of Combustion


The chemical heat of combustion ΔHc shall be either determined by:
(a) acknowledged rules of technology, described e.g. in standards such as ASTM D 240, ISO 13943 86.1 to 86.3 and NFPA 30B, or found in the scientifically established literature; or
(b) applying the following calculation method:
The chemical heat of combustion (ΔHc), in kilojoules per gram (kJ/g), can be calculated as the product of the theoretical heat of combustion (ΔHcomb), and a combustion efficiency, usually less than 1,0 (a typical combustion efficiency is 0,95 or 95%).
For a composite aerosol formulation, the chemical heat of combustion is the summation of the weighted heats of combustion for the individual components, as follows:
where:
ΔHc = chemical heat of combustion (kJ/g) of the product;
wi% = mass fraction of component i in the product;
ΔHc(i) = specific heat of combustion (kJ/g) of component i in the product.
The person responsible for the marketing of the aerosol dispenser has to describe the method used for determining the chemical heat of combustion in a document to be made readily available in English at the address specified on the label in accordance with regulation 3(8)(a)(i), if the chemical heat of combustion is used as a parameter for assessing the flammability of aerosols, according to the provisions of these Regulations.

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Source: https://www.legislation.gov.uk/uksi/2009/2824/schedule/1A/paragraph/1.10 (the official version)
Page: https://openlegislation.uk/aerosol-dispensers-regulations-2009/schedule-1A/paragraph-1.10
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.