2.3.4. Additional Classification Considerations
2.3.4.1. The chemical heat of combustion (ΔΗc), in kilojoules per gram (kJ/g), is the product of the theoretical heat of combustion (ΔΗcomb), 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:
|
ΔΗc |
= |
chemical heat of combustion (kJ/g); |
|
wi % |
= |
mass fraction of component i in the product; |
|
ΔΗc(i) |
= |
specific heat of combustion (kJ/g)of component i in the product. |
The chemical heats of combustion can be found in the literature, calculated or determined by tests (see ASTM D 240 as amended — Standard Test Methods for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter, EN/ISO 13943 as amended, 86.l to 86.3 — Fire safety — Vocabulary, and NFPA 30B as amended — Code for the Manufacture and Storage of Aerosol Products).