Halogen Acid Gas Test

Objective

Determine amount of halogen acid gas evolved during the combustion of compounds based on halogenated polymers and compounds containing halogenated additives taken from electric or optical fire cable constructions.

Reference Standard

IEC 60754-1Test on gas evolved during combustion of materials from cables.

Part 1 Determination of the halogen acid gas content.

Test Detail

A sample consist of 500 mg to 1000 mg shall be stored at least 16 h at a temperature of 23 ± 2°C and relative humidity 50 ± 5%.

The sample is heated in a stream of dry air at uniform heating rate increase over a time of 40 min ±5 min and maintain at 800° c ± 10°c for 20 min and the gases absorbed in 0.1 M sodium hydroxide solution. The amount of halogen acid gases is then determined by acidifying the solution with nitric acid, adding a measured volume of 0.1 M silver nitrate solution and back titrating the excess with 0.1 M ammonium thiocyanate using ferric ammonium sulphate as the indicator.

Calculate the amount of halogen acid.