Worker seriously injured by meat processing machine

Possible control measures to prevent similar incidents

A person conducting a business or undertaking (PCBU) has duties under WHS legislation to ensure, so far as is reasonably practicable, the provision and maintenance of safe plant. The WHS Regulation includes more specific requirements for PCBUs to manage the risks of plant, as well as other hazards associated with the workplace.

Effective control measures for plant and machinery include a combination of controls. Some risk control measures can include but are not limited to the following examples.

Guarding

Physical or other barriers that increase safety for operators and others involved in the normal operation, servicing, and maintenance of machines. Guarding can perform several functions including:

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

The body and lid of a centrifuge is typically designed to guard against access to the spinning components and materials within it during operation. However, it must also be designed to minimise the risk of objects becoming ejected from the machine during operation (e.g. The centrifuge, including the lid/enclosure and locking mechanisms, must be designed to withstand (and contain) any forces from materials or components that have the potential to fail and/or be released within the centrifuge).

A centrifuge and its components (e.g. lid and locking mechanisms) must be inspected and maintained in accordance with the manufacturers’ instructions and intended design. For example, if any of the lid locking mechanisms are damaged, missing or inoperable, the centrifuge must not be used unless the locking mechanisms are replaced and/or repaired so that they will perform in accordance with (or provide at least an equivalent level of safety to) the intended function of the manufacturers’ original design.

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

• a permanently fixed guard if access to parts of the plant requiring guarding is not necessary during operation, maintenance, or cleaning (for example, distance guards on a feed chute). Permanently fixed barriers have no moving parts.
• an interlock guard is connected to the plant's operating controls so the plant can't operate when the guard is open. The guard should not be able to open or be removed until the moving parts (i.e. cutting blade) have stopped. When designing interlock guards, consider any hazards that could be created by automatic restarting of the machine when the interlock guard is re-closed.
• a fixed guard, which can only be altered or removed with a tool not normally available to the machine operator
• a presence sensing system which detects when a person (or part of a person's body) enters the danger zone and stops a machine. Photoelectric light beams, laser scanners and foot pressure mats are examples of these type of guards. They rely on sensitive trip mechanisms and the machine being able to stop quickly.

Machine guarding and interlocks should be inspected and maintained at regular intervals.

Operational controls

Operational control devices should be designed:

• to enable the plant to be ‘fail safe’, for example when hand pressure is released on a lever controlling up and down movement, the lever will return to the neutral position and movement will stop
• to withstand the rigours of normal use, undue forces and environmental conditions
• so they are located outside danger zones and readily accessible for maintenance
• to be within easy access of the operator
• so the intended function can be easily read and understood, especially in the case of dials and gauges
• so the movement of the control is consistent with established convention, for example anticlockwise to open, clockwise to close
• so they are positioned to maximise visibility of the whole plant.

System of work

Risks can be further minimised by implementing a safe system of work with administrative and Personal Protective Equipment (PPE) controls. This could include, but is not limited to:

• inspection of the plant . A person with management or control of plant at a workplace must review safety information and inspect each item of plant in the workplace and observe how it is used. You should also review the manufacturer’s and the supplier’s instruction for safe set-up and use of the plant. Inspection of plant should be conducted in accordance with a regular maintenance system to identify:
  • deficiencies in plant such as 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.

• implementing a lock out/tag-out procedure to ensure the plant is isolated and de-energised from all energy sources prior to workers accessing any parts of the machine. This ensures the plant cannot be inadvertently operated while workers are clearing blockages, performing maintenance or cleaning work
• consulting with workers and their health and safety representatives 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
• 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, operate and maintain the plant.

• workers who operate and perform work on 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
• gloves (if appropriate for the task), protective footwear, eye protection, hearing protection, and high visibility clothing.

Administrative controls and PPE must not be used as the primary control measure when higher order controls are reasonably practicable

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.