Three elements are required in combination to ignite a fire and keep it burning – the fire triangle – ignition, fuel and oxygen. Although each element of the fire triangle is equally as important, today we will be looking at ignition sources, particularly the most common sources of ignition in the workplace.

What is an Ignition Source?

An ignition source is a thing or occurrence that has the potential to produce enough heat energy to ignite a flammable material or substance. Though many workplace items, materials and substances have the potential to catch fire, some industries are more abundant than others: industries which rely on processing flammable gases, liquids, materials and metals are far more likely to create a flammable environment than an office building or pet shop, for example.

Some workplaces have easily identifiable ignition sources – such as a furnace or soldering iron, however, other sources may not be so obvious, placing extra importance on the need to conduct thorough fire risk assessments. Those will help you identify potential sources of ignition, as well as any behaviour that may increase the risk of fire. 

Four Most Common Types of Ignition Sources in the Workplace

Within the workplace, there are four common types of ignition sources to look out for:

  1. Chemical
  2. Electrical
  3. Mechanical
  4. Thermal

We will explain them in more detail below.

Chemical Sources of Ignition

Although the fire triangle is the typical reaction required to cause a fire, you must also be aware of chemical ignitions, which are caused by exothermic reactions, such as exothermic polymerisation or a reaction between sodium metals and air.

Electrical Sources of Ignition 

Even though electrical ignition sources are some of the most commonly considered sources of ignition, they are, perhaps, the most misunderstood. Typically, fires caused by electrical devices ignite via sparks from power outlets or exposed cables or an excessive buildup of electrostatic current.

Some common sources of electrical sources of ignition include:

  • Sparks
  • Electrical faults
  • Electrical cooking equipment
  • Static electricity
  • Overloaded electrical circuits
  • Electric heaters
  • Overclocked electrical equipment

Mechanical Sources of Ignition

Perhaps the most overlooked source of ignition, mechanical equipment in the workplace presents a fire hazard from excessive frictional heat, fracturing materials or sparks – particularly dangerous to businesses who store, handle or use flammable liquids and gases.

Common mechanical sources of ignition include:

  • Excessive friction
  • Sparks 
  • Overheating machinery or peripheral equipment
  • Radiated heat

Thermal Sources of Ignition

These sources of ignition can vary in size and scope: any item that gives off heat via a flame or directly hot surface can fall under this category. Examples include:

  • Blowtorches
  • Cigarettes
  • Cigarette lighters
  • Gas/electrical hobs/stoves
  • Glowing embers
  • Electric lamps
  • Soldering irons

Reducing Ignition Sources

It is critical to ensure that all unnecessary naked flames, heat sources and erratic chemicals are removed from the workplace or safely stored from potential ignition sources and locations.

Workplace smoking should be completely forbidden within all enclosed spaces and buildings to mitigate the potential of fire caused by smoking.

Common Fire Hazards to Consider

To correctly identify potential sources of ignition, you should also be aware of what commonly fuels fires at the workplace. 

Electrical Devices

Commonly found within the workplace, electrical devices are often a source of ignition and fuel for fires. Whether the fire is caused by extension cables that have been overloaded through daisy-chains or exposed wiring of a damaged power cord, the danger of fire remains the same and all devices within the workplace should be assessed regularly to mitigate the risk of fire.

PAT testing is used to determine and identify that electrical equipment and devices are in a safe-to-use condition and free from the potential to cause harm or contribute to the ignition of a fire. Although PAT testing of electrical devices is not a legal requirement, workplaces are required to ensure compliance with the fire safety regulations, as faulty equipment is one of the top 5 common causes of fire at work. 

Combustible and Flammable Materials

Many workplaces will use and store highly reactive chemicals and/or flammable materials: in such situations, it is critical to store such potential fuel sources in secure, fire-resistant locations and away from ignition sources.

When relocating such materials, extreme care must be taken to avoid chemical reactions or ignition sources: unless necessary for their function, which should then be conducted in highly controlled conditions, following stringent safety processes.

Reducing Risks of Fire to Staff

Important to workplace fire safety is the training and education. For example, fundamentally making it known that the blocking of walkways and fire exits is absolutely forbidden and that there is zero-tolerance for such behaviour. You should also appoint and provide training for fire marshals whose duties include doing visual inspections of the workplace for potential hazards.

To ensure that evacuation is possible, there must be a clear fire emergency evacuation plan (FEEP) in place, all escape routes and designated fire exits must be clear and fire doors must be functional, free from any obstruction and maintained for operational integrity. All fire escape routes and exits should be visibly signed, whilst fire-resistant doors must be kept closed when not being used to prevent the spread of fire.
To keep a safe working environment for employees, it is critical to carry out regular fire risk assessments to locate all potential fire risks and new sources of ignition.