Worker seriously injured by dough mixer

In November 2021, a worker suffered serious hand and arm injuries after becoming entangled in a dough mixer they were operating.

Early enquiries indicate the worker attempted to retrieve a glove from the mixing bowl while the machine was still operating.

Investigations are continuing.

Safety issues

There are significant risks associated with using plant and severe injuries can result from the unsafe use of plant including:

• limbs amputated or crushed by unguarded moving parts
• electric shock from plant that is not adequately protected or isolated.

Plant and machinery come in many different shapes and sizes including mixers. Hazards associated with dough mixers and other similar machines include but not limited to:

• exposed hoppers that give access to moving parts of machinery such as rotating metal shafts and rods
• machine operation while covers or guarding are removed or opened.

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, starting with the aim of eliminating the hazard, which is the most effective control.

Possible control measures to prevent similar incidents

A PCBU must eliminate risks arising from plant in the workplace, or if that is not reasonably practicable, minimise the risks so far as is reasonably practicable. The Work Health and Safety Regulation 2011 includes more specific requirements for PCBUs to manage the risks of plant.

In most cases, a combination of the control measures will provide the best solution to minimise the risk to the lowest level reasonably practicable. Some common risk control measures can include but are not limited to the following examples.

Engineering controls are physical control measures to minimise risk. Guards for example; are a physical or other barrier that can perform several functions including:

• preventing contact with moving parts or controlling access to dangerous areas of plant
• preventing ejected parts or off-cuts from striking people.

More than one type of system may be required to ensure the safe operation of machinery or plant. Examples include:

• permanently fixed physical barriers – these are designed to be welded or incorporated into the body of the machine and where access to parts of the plant is not necessary during operation, maintenance or cleaning
• interlocked physical barriers – an interlock guard is connected to the plant's operational controls. The guard can:
  • prevent the plant from operating until the guard is closed
  • remain locked while the plant is in operation and, where it takes time for the dangerous parts to come to rest, incorporate a delay before it can be opened
  • not be locked but stop the operation of the machine when opened.

Figure 1 shows a hinged top guard on the food mixer which has a positively operating insertion key that automatically cuts off the plant's power when the lid is opened or removed. If the moving parts do not stop immediately once the power is cut off, then a guard should be designed to delay release of the locking mechanism.

Figure 1: Food mixer with interlocking guard

• Physical barriers securely fixed in position should be easy to remove and replace but only with the aid of a special tool, for example a spanner, Allen key or similar tool. They should only be opened when the machine is not in operation. The special tool should not be the same as any tool issued to and used by the operator of the plant when the operator is performing their normal work.
• Presence-sensing systems, if physicals guards are not reasonably practicable, these systems can detect when a person or part of a person’s body enters a defined area and stop the machine before the person or part reaches the danger zone. Examples of presence-sensing systems are photoelectric lights beams, light curtains, laser scanners and foot pressure mats.

Operational control devices should be designed:

• to be within easy access of the operator, easily read and understood
• so the desired effect can only occur by intentional control operation, (for example providing a starting control)
• to be outside danger zones and readily accessible for maintenance.

If risk remains, it must be minimised by implementing administrative controls. For example developing a safe system of work that includes:

• providing information, training or instruction to workers that is suitable and adequate in a way that is readily understandable. This includes safe work procedures with instructions on:
  • the correct use of guarding and other control measures
  • how to safely access and operate the plant
• workers who operate plant should be competent or suitably supervised during training
• retaining all operating manuals and instructional material provided by the manufacturer to correctly operate and maintain the plant
• consulting with workers as early as possible when planning to introduce new plant or change the way plant is used. Workers should be encouraged to report hazards and health and safety problems immediately so the risks can be managed.
• inspection of plant is conducted in accordance with a regular maintenance system to identify:
  • deficiencies in plant, for example; wear and tear, corrosion and damaged parts
  • adverse effects of changes in processes or materials associated with the plant
  • inadequacies in control measures that have been previously implemented.

The control measures you put in place should be regularly reviewed to make sure they are effective. If the control measure is not working effectively it must be revised to ensure it is effective in controlling the risk.

More information

• Managing the risks of plant in the workplace Code of Practice 2021 (PDF, 1.57 MB)
• How to manage work health and safety risks Code of Practice 2021 (PDF, 0.65 MB)
• Machine guarding - film
• Isolating machinery when not in production
• Guide to machinery and equipment safety (PDF, 1.46 MB)
• Manufacturing fixed plant - Self-assessment tool (PDF, 1.49 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.