To prevent fires, know the risks

To prevent fires, know the risks

10/13/2017 - SPI

In Canada, numerous fires occur each day. Even if the number of people injured remains quite low, the direct consequences, such as material damage and production loss, as well as indirect consequences, are high: loss of clients, unemployment period, business uncertainty… It is essential to know the fire hazards and implement the resulting preventive measures. In 70% of cases, a company affected by a fire will never completely recover.

Prevent fire hazards within your organization

Fire prevention should occur at the earliest possible stage, ideally when designing the facilities or implementing a production process. The employer must first take into account the regulation according to the type of building to be built.

Fire hazard prevention consists mainly of eliminating the possible causes of fire, implementing an intervention plan to smother the start of a fire and stopping its spread, limiting human and material consequences, as well as training and informing the personnel.

Understanding fire to counter the risks

The Fire Triangle

The Fire Triangle illustrates the three essential conditions to produce a fire. If one of the three elements is missing, a fire can’t start: this is the fundamental principle of fire prevention.

  • Presence of an oxidizing agent (usually oxygen in the air)
  • Presence of fuel
  • Presence of an ignition source

At workplaces, oxygen in the air, or oxidizing agent, is always present. Therefore, the risk of fire depends on the fuel and potential ignition sources. A fire can develop and expand extremely quickly when in contact with fuel, as 90% of the energy released by the combustion reaction will be used to the propagation of flames, and this through 4 types of transfer:

  • Conduction: heat transfer through a same material
  • Convection: heat transfer through upward movement of heated air (hot smoke or gas)
  • Radiation: heat transfer to materials close to the fire through infrared radiation
  • Displacement of combusting substances: flying embers and sparks, spreading of burning liquids, etc.

Combustible products

Generally, most solid products are susceptible of generating combustion. Only inorganic materials such as sand, concrete, sodium salt and potassium do not burn. Some of these products are used to extinguish fires.

Combustible products and materials are usually encountered in one of these states:

  • Solid: paper, wood, cardboard, plastic, metals…
  • Liquid: solvents, petroleum products, gasoline, varnish, degreaser, oils…
  • Gas: methane, butane, propane, acetylene…

Ignition sources

Ignition sources can come from flames or hot surfaces, by mechanical operations such as grinding or welding, or caused by electrical elements. Sometimes, the presence of combustible elements cannot be avoided as they are related to the activity or premises. Therefore, all organizations are at risk of fire if there are ignition sources present. The suppression of all combustibles and/or ignition sources can be difficult to achieve, and it is essential to implement measures that allow efficient and quick action as soon as a fire starts to alleviate its impact.

Fire hazard analysis

The assessment of fire hazards requires the identification of situations where the three elements of the fire triangle are present. The origin of the fire is mainly caused by the presence of combustible products. So, it is crucial to list all the products, determine their nature, know their physicochemical characteristics and respect their use and storage requirements.

Also, the fire can be caused by the working conditions (temperature, pressure, exothermic reactions, decomposing products, cooling conditions …), or by a potential malfunction (cooling system shutdowns, product leakage, foreseeable shutdowns, accidental product feed cut-off …)

Preventive measures

Following the risk assessment, the organization must implement preventive measures to reduce the risk of fire and its consequences. To avoid the risk of fire, it is imperative to act on at least one of the triangle of fire elements.

Actions on fuel

  • Replace the fuel by an incombustible product or one less combustible.
  • Intervene in the state of matter division (the more it is divided, the easier and quicker the combustion).
  • Limit the quantities used and stored.
  • Absorb the emissions of combustible products.
  • Clean by suction frequently and keep the premises tidy.

Actions on ignition sources

  • Actions on processes and materials
  • Cooling (chemical reaction, heating due to gas compression …)
  • Grounding electrical equipment
  • Electrical material and installations compliant to standards
  • Temperature reduction on the surface of heating elements
  • Implementation of regular maintenance and control inspections of electrical installations, detectors and thermographic devices

Actions on oxidizing agents

  • Reduce the oxygen level to create a non-flammable atmosphere by introducing an inert gas (nitrogen, argon, helium …) Beware, as oxygen reduction can harm an employee entering this specific area.
  • Isolate oxidizing agents (oxygen, peroxides…) from combustible products.

In addition to the preventive measures targeting one of the elements of the fire triangle, prevention also includes the training of the stakeholders. The actions include the implementation of the adapted signage, staff training, evacuation planning, and the intervention of the internal rescue teams.

Limit damages

Even with excellent preventive measures, unwanted combustion can happen at any time. Apart from the applicable measures to the three elements of the fire triangle, it is essential to have an action plan in case of fire as well as the necessary equipment to cut off the fire at the source.