Regulator issues warning after static electricity ignites flammable vapour

WorkSafe Victoria recently issued a safety alert following two separate incidents that involved 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.

The alert reminded employers and occupiers of premises where dangerous goods are stored and handled about managing the risks associated with decanting and blending flammable liquids.

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, and accumulation of static electricity may lead to a spark igniting flammable vapours.

The alert said that 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. 

To control risks associated with decanting and blending flammable liquids, the alert 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:
    o Ensure ventilation systems are maintained and are functioning efficiently.
    o Keep containers closed when not in use.
    o Store containers away from the hazardous areas.
    o Clean up any spillage immediately and ensure waste materials are disposed of safely
    o Dispose of any unused flammable liquids.