CRITERIA 3.3 – The type of firefighting equipment is identified in relation to specific types of fires

Refer to Criteria 3.1 & 3.2

Portable Fire Extinguishers – Selection

Most fires, if detected early enough, can be easily extinguished through the prompt application of the correct type and appropriate quantity of extinguishing agent.  Portable fire extinguishers are designed to fulfil this purpose provided they contain the most suitable extinguishing agent for the risk being protected.

There are several factors concerning portable fire extinguishers which, if implemented during pre-fire planning, will give the user every chance of successfully extinguishing a fire during those first few minutes.

Factors affecting your choice

The following factors need to be considered to ensure that the correct extinguisher is
selected:

The type of combustible material on site

• Some extinguishers can be used on a variety of combustible materials, but they may have a limited suitability on specific materials. Reference to suitability appears later in this module.

The possible size of a fire.

• Some extinguishers, whilst effective on contained flammable liquids fires, are not capable of dealing with the same amount of liquid if it is split over a large area.

Physical abilities of the operator

• Carbon dioxide extinguishers can have a mass of up to 34 kg for only 12 kg of content and would therefore be far too heavy and cumbersome for use by most people especially women. It would be preferable to install several smaller units in these circumstances.

The environment of the extinguisher

• Extreme temperatures or excessive vibration may be detrimental to some extinguishers.

Maintenance requirements

• In outlying areas empty CO² or Halon extinguishers may have to be sent away for long periods to be recharged.

Standardisation

• It would be wise to standardize on extinguishers which, even though differing in their content, would operate in the same manner. This would have distinct advantages in the training of staff that may not be able to regularly attend instruction sessions or practical drills.
• Servicing of the equipment would also be simplified as standard charges and CO² cartridges could be purchased in bulk by companies which carry out their own servicing.

Classification of fires

• The selection of extinguishing media for any risk is further simplified by classifying fires according to type.
• Fires involving combustible materials that require the same extinguishing media are grouped together and are defined in the South African Bureau of Standards Code of Practice 0105/1971 titled “Code of Practice for the Classification, use and maintenance of Portable Fire Extinguishers”.

Fires Involving live Electrical Equipment

Due to the hazardous nature of electricity, the following procedure should be used when attacking fires involving live electrical equipment.

Try to isolate the power first

• If already in a building where water has been applied, use a non-conducting item (such as a wood broom handle) to isolate switches.
• If it becomes necessary to use the hands, only use the back of the hand.
• Even when the power has been isolated, treat the equipment as though it was live at all times.
• Make sure that the correct extinguishing medium is being used.
• Non-conductive extinguishing agents should be used e.g: dry powder, CO 2.
• The extinguishing agent that does the least damage to the equipment and occupancy contents should be selected.
• Approach with caution

Use proper protective clothing if possible, e.g.: rubber gloves, insulated shoes if working where there is moisture, etc.

• Always work in pairs.
• If possible, let a qualified electrician first test the equipment before putting back into service.
• Care must be exercised when working under overhead power lines such as at bush fires for high voltage equipment e.g.: sub-stations, transformers, switchgear, follow manufacturer recommendations.

NOTE: Dry Chemical Powder is not recommended for delicate electrical equipment such as telephone equipment and electronic computers, due to the harmful effects of the power deposits