Machinery is a significant source of workplace injury risk, particularly in manufacturing facilities, fabrication workshops, mechanical workshops and industrial operations.
Moving machinery can expose workers to crushing, cutting, shearing, entanglement and amputation hazards.
Under Queensland's Work Health and Safety Regulation 2011, businesses must manage the risks associated with plant and machinery so far as is reasonably practicable.
Where guarding is used as a risk control, specific requirements apply to its selection, design and effectiveness.
Why Is Machine Guarding Important?
Machine guarding is intended to prevent workers from coming into contact with dangerous machinery components or being exposed to hazards such as ejected materials.
Examples of hazardous machinery components include:
- Rotating shafts and couplings.
- Drive belts and pulleys.
- Gears and transmission components.
- Cutting blades.
- Rollers and conveyors.
- Pressing and crushing mechanisms.
- Moving machine components.
Exposure can occur during normal operations, but also during cleaning, adjustments, maintenance and clearing blockages.
A machine that appears safe during normal production may still present significant risks when guards are opened or removed.
What Does Queensland WHS Legislation Require?
The Work Health and Safety Regulation 2011 (Qld) establishes requirements for managing risks associated with plant.
Businesses must eliminate risks to health and safety so far as reasonably practicable or, where elimination is not reasonably practicable, minimise those risks.
Section 208 addresses guarding where guarding is used as a control measure.
The regulation establishes a hierarchy of guarding arrangements based on whether access to dangerous areas is required and what measures are reasonably practicable.
The suitability of a guarding arrangement must be determined through an assessment of the machine, its operation and the hazards involved.
Types of Machine Guarding
Different guarding arrangements may be appropriate depending on the machine and its intended use.
Permanently Fixed Guards
Permanently fixed guards provide a physical barrier preventing access to hazardous machine components.
These may be appropriate where access to the dangerous area is not required during normal operation, maintenance or cleaning.
Interlocked Guards
Interlocked guards are designed to interact with the machine's control system.
They may prevent operation or initiate a safe stopping function when access to a hazardous area is possible.
The required safety function depends on the machinery, stopping time, access arrangements and risks involved.
Tool-Removable Guards
Certain guards are designed so they cannot be removed without the use of tools.
These arrangements may be appropriate where more protective guarding options are not reasonably practicable, subject to the requirements of the regulation and the relevant risk assessment.
Presence-Sensing Systems
Presence-sensing devices, such as light curtains and pressure-sensitive systems, may be used in appropriate circumstances.
These systems require careful consideration of stopping performance, access distances, foreseeable misuse and the machine's safety functions.
Presence-sensing systems should not be selected merely because they are more convenient for production.
The applicable regulatory requirements and machine-specific risks must be considered.
Common Machine Guarding Failures
Machinery inspections should consider common guarding deficiencies, including:
Missing or Removed Guards
Guards may be removed for maintenance or repairs and not reinstated before the machine returns to service.
Bypassed Interlocks
Interlocks may be deliberately bypassed to allow machinery to operate with protective guards open.
Inadequate Guarding Coverage
Gaps or openings may allow workers to reach hazardous moving components.
Damaged or Poorly Maintained Guards
Guards may become loose, damaged or ineffective through wear, modification or inadequate maintenance.
Unsafe Cleaning and Maintenance Practices
Workers may access hazardous machinery components without suitable isolation arrangements.
Older or Modified Machinery
Machines may have been supplied without appropriate guarding or modified in ways that introduce new hazards.
Identifying these issues early can help prevent serious incidents.
Guarding Does Not Replace Safe Isolation
Machine guarding and isolation procedures serve different safety functions.
Guarding is intended to prevent access to hazardous areas or components during relevant operating conditions.
Isolation procedures are used to control hazardous energy during activities such as:
- Cleaning.
- Maintenance.
- Repairs.
- Clearing blockages.
- Replacing components.
- Adjustments requiring access to hazardous areas.
Simply switching machinery off may not adequately control the risk of unexpected start-up or the release of stored energy.
Depending on the equipment and task, appropriate isolation arrangements may include securing energy-isolating devices, lockout and tagout processes, releasing stored energy and verifying that the equipment is in a safe state before work begins.
Isolation arrangements should be developed according to the machinery, energy sources and foreseeable hazards.
Practical Example: Clearing a Machine Blockage
Consider a production machine that regularly becomes blocked during operation.
Workers may be tempted to open a guard and reach into the machine to remove the blockage.
If the machine has not been properly isolated, workers may be exposed to unexpected movement or stored energy.
A suitable risk assessment should consider:
- Why blockages are occurring.
- Whether the hazard can be eliminated through equipment or process changes.
- Whether guarding and interlocks are appropriate and effective.
- How blockages can be cleared safely.
- What isolation arrangements are required.
- Whether workers have been trained in the safe procedure.
The objective should be to address the underlying risk rather than relying solely on instructions telling workers to be careful.
What About Older and Second-Hand Machinery?
Older and second-hand machinery may not have the same protective features as newer equipment.
However, the age of a machine does not remove a business's WHS obligations.
Before machinery is used, businesses should assess the risks associated with its condition, guarding arrangements and intended operation.
This is particularly important where machinery has:
- Been purchased second-hand.
- Been imported.
- Been modified.
- Had original guarding removed.
- Been repurposed for different activities.
- Been operated without current instructions or maintenance information.
Where existing guarding is inadequate, appropriate controls must be determined and implemented before exposing workers to the relevant risks.
Some modifications may require specialist engineering assessment, design or validation.
How Can Businesses Keep Machine Guarding Effective?
Guarding arrangements should be reviewed and maintained throughout the machinery's operational life.
Practical measures include:
- Maintaining an inventory of relevant plant and equipment.
- Completing machinery risk assessments.
- Inspecting guards and safety devices at appropriate intervals.
- Identifying and addressing damaged or bypassed guarding.
- Establishing appropriate isolation procedures.
- Training workers in safe operation and maintenance requirements.
- Consulting workers about machinery hazards and practical operating conditions.
- Reviewing risk controls following incidents, modifications or other relevant changes.
Where guarding or other safety controls are defective, the business should assess whether the machinery can be used safely and prevent unsafe operation until appropriate controls are restored.
How Can Overwatch Safety Solutions Help?
Overwatch Safety Solutions assists businesses in identifying machinery hazards, assessing plant-related risks and developing practical workplace safety controls.
Our services can include:
- Plant and machinery risk assessments.
- Workplace safety inspections focusing on machinery and guarding.
- Identification of missing, damaged or inadequate guards.
- Review of machinery isolation and lockout procedures.
- Assessment of risks associated with older, modified and second-hand machinery.
- Development of safe operating procedures and safe work instructions.
- Plant inspection checklists and safety-related maintenance documentation.
- Corrective action plans and recommendations for addressing identified hazards.
- Ongoing WHS advisory and compliance support.
Our assessments consider how machinery is operated, cleaned, maintained and repaired, rather than focusing only on normal production activities.
Where specialist guarding design, engineering modifications or safety-system validation is required, appropriately competent engineering specialists should be engaged.
Frequently Asked Questions
Is PPE enough instead of machine guarding?
PPE should not be relied upon as a substitute for suitable guarding where guarding is required to control machinery hazards. PPE generally provides a lower level of protection against contact with dangerous moving components.
Do older machines need guards?
Yes, businesses must manage machinery risks regardless of the age of the equipment. The necessary controls depend on the hazards and applicable WHS requirements.
Can workers remove guards for maintenance?
Guard removal may be necessary for certain maintenance activities, but the associated risks must be controlled. Appropriate isolation and other safety measures may be required before access is permitted.
Are light curtains acceptable under Queensland WHS legislation?
Presence-sensing systems may be acceptable where the applicable regulatory conditions are met and the system is suitable for the machinery and risks involved.
Does every machine need a written risk assessment?
The legislation requires risks to be managed, but does not universally prescribe a separate written risk assessment for every machine. Documenting assessments is often appropriate, particularly for complex machinery or significant hazards.
Sources: Work Health and Safety Regulation 2011 (Qld), including section 208; Managing the risks of plant in the workplace Code of Practice 2021.
Last reviewed: October 2026.