Different Types of Fires and How They Start
To provide the most comprehensive and reliable fire protection for your business or industrial premises, you and your employees should have an understanding of the classification system for fires in the UK.
Not every instance of fire is the same, and knowing the differences between the types of fires and how they start is a key component of fire safety. To give you a clear idea of the five classes of fire you might encounter, our team have put together this handy guide.
Class A – Ordinary combustibles:
Class A fires are probably the most common. They involve combustible solid materials such as wood, plastic, paper, cloths and pieces of clothing. These types of fires can occur just about anywhere, and can spread quickly as long as there are enough combustible materials, oxygen and heat to sustain it.
Most commercial and industrial premises are likely to contain a large number of common combustibles, so preventing Class A fires requires strict and regular site maintenance to ensure fire hazards are kept to a minimum.
Class B – Flammable liquids:
These fires can be incredibly dangerous. They involve flammable liquid substances such as petrol, alcohol, oil, solvents, paints and kerosene.
Class B fires can occur in any area where flammable liquids are stored or used such as garages, construction sites, warehouses, hospitals and laboratories.
Flammable liquids have a low flash point so they can burn easily when an open flame or other ignition point is introduced. A match, lighter or spark can ignite the vapours of a flammable liquid, so proper storage is required to minimise the chances of a Class B fire occurring.
Sites should limit the amount of flammable liquids present as far as possible, and should be kept well clear of any source of ignition. Open flames should never be introduced to an area where flammable liquids are stored.
Class C – Flammable gases
In the UK, Class C fires involve various flammable gases such as hydrogen, butane and propane. Flammable gases are highly volatile and pose a major fire and explosion risk, and therefore require secure storage in sealed containers such as gas cylinders.
The concentration of flammable gases in the air will dictate the potential fire hazard, and even small or isolated leaks of these gases can lead to quick ignition if an open flame or igniter is introduced.
Any industrial or commercial area which use flammable gases should keep them stored in a secure location that is strictly monitored and kept clear of open flames.
Class D – Flammable metal objects
Metal-based fires are not highly common as not all metals are flammable. The main risks for Class D fires is smaller deposits of metal, such as shavings or powders. Sheet metal and thick, solid metals are less of a fire hazard. Because of this, industrial settings where metal work, such as cutting, is performed are at greater risk of Class D fires.
Some combustible metals include titanium, potassium, lithium and magnesium. If metal shavings or finer deposits of flammable metals are common in the worksite, regular cleaning should be carried out to limit the concentration of metals at any one time. Sparks or open flames should also be kept clear of these areas.
Electrical fires refer to fires caused by electrical equipment. This can be from faulty wiring, frayed cables, broken electrical appliances/tools, short circuits and overloading sockets.
Electrical fires can be very common, with potential hazards present in virtually every commercial or industrial setting. If an electrical item or appliance is showing signs of a fault or deterioration, power to the item should be cut immediately and the appliance should be kept out of use until it is repaired or disposed of.
Water should be kept clear of any electrical equipment to minimise the risk of spillages. Whenever a spillage occurs on an power source, it should be immediately disconnected. If left plugged in, short circuiting can occur, leading to sparks, which can then create a fire.
Class F – Cooking oils, vegetable oils and fats:
These kinds of fires are more common in restaurants and commercial kitchens. Typically they involve fat, oil or grease cooking at extremely high temperatures. Most often, they occur when pans containing oils are left unattended or are not carefully monitored.
The high flash point of cooking oils and fats make Class F fires a different proposition than, for instance, Class B fires. Prevention is incredibly important, and busy environments like large commercial kitchens should enforce strict fire safety standards.
A common cause of Class F fires relates to deep fat frying; oil can be left to cook for too long, or in too great a quantity. Deep fat frying is a leading cause of accidental fire in kitchens, so great care is required at all times. Spilled oil should be cleaned from surfaces, fryer oil should be changed regularly and pans should never be overfilled with oil.
Signs of a potential Class F fire, such as seeing or smelling smoke, means you should turn the heat off immediately before the oil reaches too high a temperature and ignites.
Target Fire Protection provide a comprehensive fire protection service for commercial properties throughout Manchester, Oldham, Rochdale, Bury and across the UK. We supply and service fire extinguishers and fire alarms, as well as carry out fire risk assessments and deliver fire safety courses to help make your premises as safe as possible. For more information on all of our services, don’t hesitate to get in touch today.