QLD: safety alert issued after worker killed by metal ejected from angle grinder

The following article is a news item provided for the benefit of the Workplace Health and Safety profession. Its content does not necessarily reflect the views of the Australian Institute of Health & Safety.
Monday, 16 August, 2021 - 12:30
Policy & legislation

Workplace Health and Safety Queensland recently issued a safety alert after a worker died from injuries sustained while he was using a 9-inch (230mm) angle grinder to cut the base of a structural steel member at a commercial construction site in Brisbane.

It appears a small metal shard was violently ejected from the cutting work and struck his neck. No guarding was fitted to the angle grinder at the time.

While findings are not yet confirmed and investigations are continuing into the exact cause, the safety alert said angle grinders have been involved in many serious incidents before this one, including fatalities.

Common injuries are amputated fingers, severed tendons and deep cuts to the face, upper body or legs. Incidents involving angle grinders can occur in all industry sectors.

The increased power and size of a 9-inch angle grinder can cause more severe kickback and gyroscopic effect as the grinder is more difficult to control than smaller grinders. It’s important to note that a risk assessment to identify alternative methods and tools should be carried out prior to selecting a larger angle grinder.

The alert said to use the hierarchy of controls to help decide how to eliminate and reduce risks in your place of work. The hierarchy of controls ranks types of control methods from the highest level of protection and reliability to the lowest.

The alert also suggested a number of possible control measures to prevent similar incidents, and said employers and self-employed people must control the risk associated with power tools, including 9-inch angle grinders.

Before operating larger angle grinders, you must ensure:

  • the correct guard supplied by the manufacturer is fitted correctly

  • the right sized disc is fitted, including matching the mounting hole with the spindle flange
  • discs are marked with the maximum permissible operating speed (rated speed) in RPM
  • the angle grinder is marked with its maximum operating speed (rated speed) in RPM
  • the rated speed marked on the disc is not less than the rated speed marked on the angle grinder
  • discs are inspected for damage before use and damaged discs are thrown out and not re-used
  • the correct disc for the task is selected—only use a grinding disc for grinding as grinding with a cutting disc increases the likelihood of it breaking
  • discs are installed correctly and the centre nut tightened in accordance with the power tool manufacturer’s instructions and using the tightening tool supplied by the manufacturer—using another method such as a punch and hammer can damage the disc and grinder
  • the angle grinder is held with both hands and the side handle is inserted on the side of the unit that gives the best grip for the work activity
  • the grinder is run up to full speed before cutting or grinding
  • the correct spindle flange and lock nut for the disc is used and fitted according to the manufacturer’s instructions. The type of flange or fitting method may vary for cutting and grinding discs. If the incorrect flange and lock nut combination is used, the disc can break
  • exclusion zones are set up so that other people cannot be injured if the worker loses control of the grinder or the disc breaks.

PCBUs must first consider controls that most effectively eliminate the risk or, where not reasonably practicable, that minimise the risks. Hazards such as the ejection of metal may be minimised by implementing engineering controls such as guarding.

Guards should be used on all angle grinders due to the risks associated with grinding debris and sparks and the disc disintegrating and being ejected or cutting the worker. AS 1788, Abrasive Wheels, provides guidance on guarding abrasive wheels while AS/NZS 60745 Hand-held motor-operated Electric Tools – Safety (series), includes requirements specifically for grinders, polishers and disc-type sanders.

Administrative controls are a lower order control and can be used in conjunction with higher-order controls to minimise the risks associated with angle grinders.

Administrative control measures and PPE rely on human behaviour and supervision, and are used on their own, tend to be least effective in minimising risks. The alert said the control measures you put in place should be reviewed regularly to make sure they work as planned.