Worker killed by piece of metal ejected from unguarded angle grinder

In June 2021, 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.

Safety issues

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 (230mm) 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.

Ways to manage health and safety

Taking steps to manage risks is a condition of doing business in Queensland. Effective risk management starts with a commitment to health and safety from those who manage the business. If an incident occurs, you'll need to show the regulator that you’ve used an effective risk management process. This responsibility is covered by your primary duty of care in the Work Health and Safety Act 2011.

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. It’s a step-by-step approach to eliminating or reducing risks. You must work through the hierarchy of controls when managing risks, with the aim of eliminating the hazard as the most effective control.

Possible control measures to prevent similar incidents

Employers and self-employed people must control the risk associated with power tools, including 9-inch (230mm) 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. If the guard on an angle grinder has been removed:

• there is nothing to stop debris or broken pieces of a disk hitting the worker
• there is a higher risk of a worker's hand contacting the unguarded moving disc
• there is a greater risk of the disc being damaged when the grinder is put down and the weight of the grinder is resting directly on it.

Photograph 1 shows a 9-inch (230 mm) angle grinder correctly fitted with guard and the right sized disc.

Photograph 1: 9-inch (230 mm) angle grinder with guard and right sized disc fitted.

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. They can include:

• providing the information, training, instruction and supervision necessary to ensure workers who operate angle grinders are competent to use them safely
• manufacturer’s operating manuals and instructions are available to workers
• practical and hands on training is given to workers, taking into account literacy levels, work experience and the specific skills required for safe use of the equipment
• ensuring worker training, experience and competency aligns with the requirements and complexity of the task.

Any remaining risk must be further minimised with suitable personal protective equipment. For example:

• safety goggles, safety glasses, face shields
• hearing protection e.g. earmuffs
• dust masks, as appropriate to the task
• gloves and leather aprons and jackets (workers using power tools including angle grinders must not wear loose clothing or jewellery and must securely tie back long hair so that it does not become caught in a moving part of the tool).
• safety footwear which is:
  • suitable for the type of work and environment
  • comfortable with an adequate non-slip sole and appropriate tread
  • checked regularly to ensure treads are not worn away or clogged with contaminants.

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

More information

• How to manage work health and safety risks Code of Practice 2021 (PDF, 0.65 MB)
• Managing the risks of plant in the workplace Code of Practice 2021 (PDF, 1.57 MB)
• Safety alert – Guards and discs on angle grinders
• Safety alert – Multi-cutters and other discs on power tools and air tools
• Angle grinder self assessment tool (PDF, 0.48 MB)

Support for people affected by a serious workplace incident

For advice and support:

• Visit our Support for families of workplace fatalities, illness and injuries Facebook page
• Email ohs.coronialliaison@oir.qld.gov.au.