The Importance of Controlling Fire and Explosion Risks

Fire and explosion incidents can have severe consequences, including injuries, fatalities, and property damage. At WorCover Queensland, we stress the importance of controlling ignition sources, such as naked flames, sparks, and even mobile phones, especially in areas where flammable atmospheres may be present.

It is imperative for a person conducting a business or undertaking (PCBU) to take proactive measures to prevent the possibility of fire or explosion resulting from the ignition of flammable substances within hazardous areas or atmospheres. Specific controls mandated by Section 355 of the Work Health and Safety Regulation 2011 are in place to address this concern. The PCBU is responsible for ensuring that no ignition source is introduced into a hazardous area, whether from external sources or within the space itself.

In line with safety duties outlined in Section 52 of the WHS Regulation, a PCBU must manage risks associated with ignition sources in hazardous atmospheres, particularly those related to flammable substances. A hazardous atmosphere is defined as one where the concentration of flammable elements exceeds 5% of the lower explosive limit (LEL), information typically found in a product's safety data sheet.

Hazardous areas, three-dimensional spaces with potential flammable atmospheres, demand special precautions for equipment construction, installation, and use. Examples of such areas include storage tanks, dispensing equipment, storage areas for flammable liquids, and various industrial processes involving flammable substances.

Identification of exclusion zones, categorized as Zone 0, Zone 1, or Zone 2, helps determine the probability of a flammable atmosphere's presence. Once these zones are identified, potential ignition sources—such as naked flames, electrical equipment, hot surfaces, and static electricity—should be either eliminated or controlled to mitigate the risk of fire or explosion.

It's crucial for workplaces to conduct hazardous area classifications and implement measures to address identified ignition sources. This involves eliminating or controlling potential sources of energy that could ignite a flammable atmosphere. Examples of ignition sources include pilot lights, electrical equipment, hot work activities, operating equipment with combustion engines, hot surfaces, and mechanical sparks.

At WorCover Queensland, we prioritize safety by promoting awareness and control measures to prevent fire and explosion incidents associated with hazardous chemicals.


Risk control measures

Key control measures for managing these risks include:

  • identifying and managing hazardous areas
  • controlling emissions of flammable vapours, gases and mists (see below)
  • use of ventilation systems to control vapours during both normal and abnormal conditions (e.g. leak or spill)
  • eliminating ignition sources from hazardous areas (see below)
  • installing systems to detect leaks of flammable gases or vapours and enable response actions to be taken
  • using intrinsically safe or flameproof equipment
  • substituting flammable materials for ones that are less flammable or combustible
  • ensuring incompatible materials (e.g. oxidizers and oils) are separated or segregated
  • reducing quantities of flammable and combustible materials, including items that contribute to the fire load but that are not hazardous chemicals themselves (e.g. wooden pallets, oil)
  • ensuring equipment used in handling flammable hazardous chemicals is maintained in accordance with manufacturer's instructions
  • adopting good housekeeping practices to minimise accumulation of combustible dusts.

Controlling flammable substance emissions

Accumulation of vapours, gases, mists creates the potential for a hazardous area to exist. Vapour emissions resulting from processes can be minimised by:

  • the use of enclosed container and transfer systems and vapour recovery connections
  • keeping lids open only for the minimum period required for transfer
  • minimising exposed surface areas (e.g. area of spread for leaked or spilled liquid)
  • avoidance of splash filling
  • minimising the temperature of liquids being processed or transferred
  • providing ventilation, e.g. mechanical extraction for all sources of vapour and vent to a safe area.

When heated, the vapour pressure of flammable and combustible materials may increase resulting in higher vapour emissions. Containers of hazardous chemicals should therefore be stored away from sources of heat (e.g. heaters or other heating appliances). Heat may also deteriorate packaging and increase the risk of failure of the container and product loss. Hot surfaces may also exceed a substance's auto-ignition temperature.

Controlling ignition sources

Controlling potential sources of ignition in a hazardous area may be achieved by:

  • use of suitably-rated electrical equipment (e.g. intrinsically safe or flame-proof)
  • ensuring electrical equipment is effectively maintained where poorly maintained electrical equipment can present a significant risk for example through worn brushes
  • ensuring electrical equipment is properly earthed
  • ensuring the auto-ignition temperature of the hazardous chemical is considered as some hazardous chemicals may ignite spontaneously above certain temperatures
  • implementing administrative controls such as permit systems preventing hot work (for example, welding) in these areas (see below).

Where electrical installations or equipment are required to be located or used in a hazardous area e.g. lighting, mixers and stirrers, pumps, control systems, forklift trucks, detectors, torches etc, these items must be designed and constructed so that they cannot release energy within the hazardous area that is sufficient to cause an ignition. That is, such equipment must be suitably rated for use in a hazardous area.

Such design and construction techniques include 'intrinsically safe' or 'flameproof/encapsulated' equipment. Any equipment designed and constructed to operate within a hazardous area must also be supplied with documentation stating which zone (i.e. 0, 1 or 2) it is suitable to operate within.

It is a PCBU's duty to ensure equipment within a hazardous area is consistent with the zone assigned to the area, i.e., zone 1 rated equipment must only permitted within a zone 1 hazardous area. However, zone 1 or zone 2 equipment is permitted within a zone 2 hazardous area as zone 1 equipment is more conservative than zone 2.

Safe work procedures must also account for any hazardous areas. For example adopting a hot work permit system to conduct maintenance and repair activities (see below).

Controlling static electricity

Static electricity can be created from a range of activities including the transfer of hazardous chemicals. Information on control of static electricity can be found in AS/NZS 1020: The control of undesirable static electricity in non-hazardous areas.

This standard updates the 1995 version with changes including removal of aspects related to hazardous areas and introduces a Static control assessment and a Static control plan. This standard does not consider the control of static electricity for the purpose of preventing ignition of an explosive atmosphere.

Refer to Standards Australia Technical Specification (TS) 60079.32.1:2022 Explosive atmospheres, Part 32.1: Electrostatic hazards, guidance. This document provides guidance on the equipment, product and process properties necessary to avoid ignition and electrostatic shock hazards arising from static electricity as well as the operational requirements needed to ensure safe use of the equipment, product or process.

Controlling hot work

Hot work is any process involving grinding, welding, brazing, oxy cutting, heat treatment or any other similar process that generates heat or continuous streams of sparks. Undertaking hot work in areas where flammable or combustible chemicals or other materials are present creates a significant risk of fire or explosion. Conducting hot work on containers such as drums, tanks and pipes that have not been properly decontaminated is a common cause of serious incidents. A hot work permit system is a system designed to eliminate or minimise risks from these activities by controlling when and how hot work is undertaken in these areas.

More information on hot work permit systems is available in the following Australian Standards:


replica uhren replica horloges