Fatal hot work incident

Possible control measures to prevent similar incidents

The Work Health and Safety Regulation 2011 requires specific controls for prevention of fire and explosion risks associated with hazardous chemicals. These include:

• s51 - A PCBU a workplace must manage risks to health and safety associated with a hazardous atmosphere at the workplace and;
• s52 - A PCBU a workplace must manage risks to health and safety associated with an ignition source in a hazardous atmosphere at the workplace.

A PCBU must manage risks to health and safety associated with a hazardous atmosphere. This includes identifying all sources of ignition, such as welding, hot-cutting, and grinding, which generate heat, flames, and sparks, that could cause an ignition of flammable and combustible substances.

In relation to hazardous chemicals, a hazardous atmosphere is when the atmosphere has a concentration of flammable vapour that exceeds 5 per cent of the lower flammable explosive limit (LEL) for the vapour. You must also ensure that flammable or combustible substances in the workplace are kept in the lowest practicable quantities. This includes gas cylinders and waste liquids in containers, whether empty or full.

Safe system of work

A safe system of work should be implemented to manage the fire and explosion risks associated with ignition sources and hot work activities on and around containers that may have contained flammable or combustible liquids. This can include:

• Developing and implementing specific safe work procedures that should include a hot work permit system to control when and how hot work is undertaken. More information on hot work permit systems is available in the following Australian Standards:
  • AS 1940:2004 The storage and handling of flammable and combustible liquids
  • AS 2865:2009 Confined spaces
  • AS 1674.1:1997 Safety in welding and allied processes – Fire precautions.
• Obtaining the current safety data sheet (SDS) from the manufacturer, importer or supplier of the chemical in the container or system to be worked on and making the SDS readily available to workers.
• Ensuring you keep a hazardous chemicals register for use by workers. A hazardous chemicals register is a list of hazardous chemicals stored, handled or used at a workplace – the current SDS for each of the hazardous chemicals listed must be included with the register.
• Checking what has previously been stored in the empty drum or container by reading the label and reviewing the SDS for the hazardous chemical and assessing the information provided on the safe storage and handling. If it has been found to contain flammable or combustible substances, seek to properly dispose of the container and avoid any hot work on it.
• Be wary of any container that is not correctly labelled (e.g., label has been removed or has become illegible) or has an unknown history. The best approach is to properly dispose of such containers otherwise it will have to undergo appropriate cleaning and testing to verify that there is no fire or explosion risk resulting from past contents.
• Be wary of ‘waste’ oil containers which may also hold an unknown amount of flammable liquid presenting a flammability hazard that has not been recognised.
• If there is no alternative but to perform hot-work on the container, remove all traces of flammable or combustible materials from the container to ensure it is properly cleaned of residues and vapours and certified (e.g., gas-free certificate) as vapour-free by a competent person noting that:
  • unless containers have been cleaned out to be free of flammable and combustible substances, vapours can remain in containers for many years, and
  • rinsing drums may not be enough to remove vapours from within a container.
  • oily residues won’t generate significant vapours until they are subjected to high heat as occurs with hot work, potentially creating a hazardous atmosphere within a container and increasing the risk of fire and explosion that wasn’t there before.
• Sparks and hot slags ejected from hot work can travel several metres. Fire resistant barriers should be used to prevent these ignition sources from reaching other areas where flammable and combustible materials are located to remove the risk of these materials being ignited.
• Do not use drums as a welding or work platform.
• Store used empty drums with bungs removed in a well-ventilated place away from other work areas. Removing the bung will not guarantee all hazardous residues and vapours have been naturally vented. Note that flammable vapours from flammable liquids like petrol are heavier than air and will collect at the bottom of a container and can remain there for years until actively removed.
• Keeping and maintaining fire-fighting equipment nearby.
• Providing workers, including experienced workers with information, instruction, training and supervision on fire and explosion hazards. Training should be provided to workers by a competent person with information, training, and instruction provided in an easy-to-understand manner.
• Ensuring worker training, experience, and competency aligns with the requirements and complexity of the task (workers must be trained and have the appropriate skills to carry out a particular task safely).
  • Keep records of training completed and ensure training is always fit-for-purpose. Some examples might include: How to work safely in hazardous environments, such as confined spaces, hazardous atmospheres, and hazardous areas.
  • How to safely control any fire and explosion hazards if performing hot-work on containers that have contained chemicals.
  • How to access safety data sheets (SDS) for hazardous chemicals and be able to understand key information in the SDS and container labels, and
  • The proper use, storage, and maintenance of personal protective equipment (PPE).

Emergency plans

Under the Work Health and Safety Regulation 2011, a PCBU must prepare an emergency plan to reduce the effects of an emergency involving hazardous chemicals at their place of work. When preparing an emergency plan, a PCBU must consider all relevant matters including:

• the nature of the work being carried out at the workplace
• the nature of the hazards at the workplace
• the size and location of the workplace
• the number and composition of the workers and other persons at the workplace.

A PCBU must also ensure the workplace is provided with fire protection and firefighting equipment that is designed and built for the types of hazardous chemicals at the workplace. The workplace should consider the hazardous chemicals from the perspectives of:

• the quantities in which they are used, handled, generated or stored, and
• the conditions under which they are used, handled, generated or stored, concerning:
  • the fire load of the hazardous chemicals
  • the fire load from other sources
  • the compatibility of the hazardous chemicals with other substances and mixtures at the workplace.

In Queensland, fire protection and firefighting equipment must be compatible with equipment used by Queensland Fire and Emergency Services. It must be properly installed, tested, and maintained with a dated record kept of the latest testing results and maintenance until the next test is conducted.

The control measures you put in place should be reviewed regularly to ensure they are effective.