Static electricity ignites flammable vapour

Background

There have been two separate incidents during the decanting and blending of flammable liquids resulting in two fatalities and other serious injuries. The incidents are believed to have occurred when static electricity discharged within a hazardous area resulted in an explosion and fire.

Safety issues

A hazardous area is an area where vapours, fumes, gases, and mists may create a flammable or explosive atmosphere. Sources of ignition must not be present within these areas to manage the risk of fire and explosion.

Flammable liquids can create clouds of flammable vapour when exposed to the air. This can occur through open containers, pouring, mixing, or from a spill or leak. Vapour clouds are often invisible and can build up quickly. If an ignition source is present in the area, it may cause a fire or explosion.

Ignition sources that can ignite flammable vapours include electrical equipment with motors, power points, mobile phones, forklifts, and can also include flames, heat, sparks and static electricity.

Static electricity can be created from a range of activities including the decanting and blending of flammable liquids. Static electricity is when an electrostatic spark occurs from the build-up of electrical charge on the surface of an object. Accumulation of static electricity may lead to a spark igniting flammable vapours.

Identify hazards

Employers and occupiers of premises where dangerous goods are stored and handled must identify hazards that may cause harm to employees and other people and assess the risks. In areas where flammable liquids are being blended or decanted, hazards can include:

• a fuel source, such as a flammable or combustible liquid
• a source of oxygen (usually the air)
• an ignition source (such as static electricity or electrical equipment)

Recommended ways to control risks

Implement the hierarchy of control, which is a system for controlling risks in the workplace, it helps employers to eliminate or reduce risks at work.

To control risks associated with decanting and blending flammable liquids, the following is recommended:

• Ensure employees are appropriately trained in blending and decanting procedures and familiarise themselves with the SDS before decanting
• Eliminate all ignition sources in hazardous areas. Make sure pumps and other equipment used for decanting are intrinsically safe, which are specifically designed to not create sparks.
• Ensure that all equipment, vessels and containers are bonded to maintain consistent electrical potential when decanting flammable liquids.
• Ensure equipment, vessels and large containers (>20L) transferring flammable liquids are earthed. Earthing allows any static charge that does build up to dissipate into the earth. This involves connecting the equipment to a metal conductor directly connected to the general mass of earth (either via the building subframe or an earthing stake).
• Avoid splash filling during decanting and blending of flammable liquids. Use a liquid transfer pipe which reaches as close as possible to the bottom of the container or through bottom inlet lines.
• For blending activities, complete a risk assessment as per AS1940:2017 to identify hazards and control the risk.
• Ensure employees wear appropriate PPE, avoid clothing that can generate static such as polyester.
• Ensure process hoses are electrically conductive.
• Ensure conductive fittings are used when decanting from non-conductive containers.
• For decanting and blending of quantities above 5L, where reasonably practical only use conductive/dissipative containers.
• Ensure transfers are made in closed containers or in purpose made containers that are suitable for the liquid, rather than using open containers.
• Ensure low conductive solvents such as toluene and xylenes are doped with anti-static agents (to greater than 10.000 pS/m).
• Reduce the likelihood of flammable vapours being present in the workspace:
  • Ensure ventilation systems are maintained and are functioning efficiently.
  • Keep containers closed when not in use.
  • Store containers away from the hazardous areas.
  • Clean up any spillage immediately and ensure waste materials are disposed of safely
  • Dispose of any unused flammable liquids.

Legal Duties

The Dangerous Goods Act 1985 and the Dangerous Goods (Storage and Handling) Regulations 2022 set out duties for occupiers of premises where dangerous goods are stored or handled. Relevantly, occupiers must ensure that:

• All reasonable precautions are taken to prevent any fire, explosion, damage to property or danger to the public involving dangerous goods.
• So far as is reasonably practicable, ignition sources are not present in any hazardous area within the premises.
• Any risk associated with the transfer of dangerous goods is eliminated or, if it is not reasonably practicable to eliminate the risk, is reduced so far as is reasonably practicable. The occupier must have regard measures to:
  • control spills and leaks
  • minimise static electricity
  • control vapour generation
  • ensure compatibility of the pipework with the dangerous goods being transferred

The Occupational Health and Safety Act 2004 sets out duties for employers. Employers must, so far as is reasonably practicable:

• Provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors.
• Eliminate the risk, and where the risk cannot be eliminated, it must be reduced so far as is reasonably practicable.
• Provide and maintain plant or systems of work that are safe and without risks to health.
• Ensure the safety and the absence of risks to health when using, handling and storing substances.
• Ensure that persons other than employees are not exposed to risks to their health or safety arising from the employer's conduct.
• Consult with employees, contractors and health and safety representatives about certain health and safety matters, including when identifying or assessing hazards or risks and making decisions about risk control measures.

Employers must also provide employees and contractors with the necessary information, instruction, training or supervision to enable them to do their work safely and without risks to health.

At work, employees must take reasonable care for their own health and safety and for the health and safety of others who may be affected by their acts or omissions at the workplace. Employees must also cooperate with anything the employer does to comply with occupational health and safety laws.

Related Information

The Code of Practice for the storage and handling of dangerous goods provides practical information on how to comply.