In Part 2 of this series CIA Insurers will look at the classification of fire and the correct extinguisher for each class. In part 3 of the series CIA Insurers considers the Dangers and limitations of extinguishers.
Fires involving combustible materials that require the same extinguishing media are grouped together in classes in terms of SABS code 0105.
Type Description Example
Class A Fires involving ordinary combustible materials coal, paper, plastics, wood and textiles
Class B Fires involving flammable liquids and gasses alcohols, benzene, oils, paraffin, petrol, LPG, hydrogen, acetylene
Class C Fires of Class A, B and D type occurring in the Electrical cables, generators, transformers, switchboards, live electrical installations.
Class D Fires involving metals Aluminium, magnesium, sodium, potassium and lithium
Class K Fires involving commercial restaurant cooking oils chip fryers.
In Part 3 we look at the correct extinguisher for each class.
The below shows which extinguisher is best for a specific class and what the dangers and limitations are when using the wrong extinguisher.
Extinguisher Class and Limitations/Dangers
Water
Best for Class A fires
Will cause B fires to spread, highly dangerous C fires, D may cause violent explosions
Dry Powder
Best for Class C and D fires
Dry powder does not prevent re-ignition. Deposits can have detrimental effects on machinery
Foam
Best for Class B fires
Highly dangerous class C fires
Carbon Dioxide
Safe for small Class B fires and Class C fires
Care should be taken when used in confined space. CO2 does not prevent re-ignition
Wet Chemicals
Safe for Class K fires
Not suitable for Class C fires. Can cause corrosion of certain metals.
The information contained in this article must be seen as a set of guidelines and does not purport to provide legal or other professional advice. If such advice is needed, consult with your legal or other qualified adviser. CIA will not accept any responsibility towards any person relying upon the contents hereof nor accept any liability whatsoever for the accuracy of information supplied by a third party or the consequences of relying upon it.   
Commercial & Industrial Acceptances (Pty) Ltd (CIA) can be contacted on www.cia.co.za
Scheme Executives are advised to contact their scheme’s insurance brokers to get advice on the requirements for the use of fire extinguishers in their scheme to comply with any insurance requirements.