Risk Assessment for Press Guarding and Point-of-Operation Hazards

Press guarding risk assessment should begin with the point of operation: the area where the die, ram, tooling or workpiece creates crushing, shearing, cutting or trapping hazards.

Mechanical, hydraulic, pneumatic and servo presses can cause severe injuries in a single cycle. The safeguarding requirements and applicable standards may differ by press type, control system and operation. The risk is not limited to normal production. Die setting, material loading, scrap removal, jam clearing, tool changes, maintenance and fault recovery can all expose people to hazardous movement.

The purpose of the assessment is to identify how a person could reach the point of operation or another danger zone, then select safeguarding that prevents or adequately restricts access while allowing the press to be used, maintained and adjusted safely.

Identify the Complete Press Hazard Zone

The point of operation is usually the most critical hazard, but it should not be assessed in isolation.

Review:

• upper and lower die areas
• ram, slide and bolster movement
• punch, die and tooling hazards
• moving workpieces and material ejection
• feed mechanisms and transfer systems
• coil-handling or strip-feeding equipment
• conveyors, robots and automated loading systems
• flywheels, belts, gears, pulleys and couplings
• scrap chutes and discharge areas
• accessible sides and rear areas of the press

A press may have an apparent front guard while still allowing access from the side, rear, under the tooling or through material-feed openings.

The assessment should identify the actual danger zone, including the movement of the ram, die components, stock and any connected automation.

Assess Every Operating Mode

Press guarding must account for all phases of machine use, not only the automatic production cycle.

Consider:

• normal production
• manual loading and unloading
• automatic or robotic feeding
• die setting and adjustment
• tool changes
• setup and trial runs
• fault recovery
• scrap removal
• cleaning and lubrication
• maintenance and repair
• shutdown and restart

The risk level can change significantly between modes. A press may operate with automated feeding during normal production but require personnel to work close to the die during setup, alignment or fault recovery.

Do not assume a safeguard suitable for one mode is suitable for every mode.

Identify Who May Be Exposed

The assessment should identify everyone who may approach the press or associated equipment.

This may include:

• press operators
• setters and die-change personnel
• maintenance technicians
• material handlers
• cleaners
• automation technicians
• contractors
• supervisors and inspectors

Then assess how each person could be exposed.

Examples include:

• placing stock into the die area
• removing finished parts
• clearing scrap
• aligning material feed
• reaching into the press after a jam
• adjusting sensors or guides
• changing tooling
• working near automated transfer equipment
• accessing drives, flywheels or hydraulic components

A practical safeguarding solution must account for the actual task. If workers need to defeat a guard or reach through a protective device to complete normal work, the access method needs review.

Assess Access to the Point of Operation

The main question is whether a person can place any part of the body into the point of operation while hazardous movement is possible.

Review:

• access from the front, sides and rear
• openings around material feed paths
• gaps beneath guards
• reach-through openings in mesh or panels
• access around light curtains or safety scanners
• reach-over and reach-around paths
• access during part removal or scrap clearing
• access created by adjacent machinery or conveyors
• the ability to enter a larger press enclosure

A light curtain at the front of a press does not protect access from the side or rear if those routes remain open. Likewise, a fixed side panel may not control risk if an operator can reach through a material opening or around the end of the guard.

Safety distance, opening size and the position of the actual danger zone must be assessed together.

Select Safeguarding for the Press Operation

The safeguarding method should be selected from the risk assessment and the press operation—not from product preference.

Depending on the press, tooling and production method, suitable measures may include:

• fixed or adjustable point-of-operation guards
• enclosed die areas
• interlocked movable guards
• two-hand controls or two-hand trip devices
• presence-sensing safeguarding devices, including safety light curtains or other electro-sensitive protective equipment
• pull-out or restraint devices
• automated feeding or unloading
• engineered fixtures, jigs or die enclosures
• modular perimeter guarding around automated press cells

No one safeguard is suitable for every press.

For example, fixed guarding may be practical where material is automatically fed into an enclosed die area. A light curtain may be suitable for a press with appropriate stopping performance and control reliability, provided other access routes are controlled. A two-hand control may help keep an operator’s hands away from the die during initiation, but it may not protect against access from another direction.

Assess Stopping Performance and Safety Distance

Stopping time is critical where a safeguard relies on detecting entry or interrupting access before a person reaches the danger zone.

Stopping time is particularly important where safeguarding relies on a protective device or access-control function to stop the press before a person can reach the danger zone. This may include:

• light curtains or other electro-sensitive protective equipment
• safety-rated scanners, where suitable for the application and environmental conditions
• interlocked gates
• interlocked press guards
• automated loading stations with protective devices

Two-hand controls and two-hand trip devices should also be assessed for their control arrangement, required hand position, possible access from other directions and suitability for the press operation.

The assessment should consider:

• press stopping performance
• clutch and brake condition on mechanical presses
• control response time
• protective-device response time
• the distance between the safeguard and point of operation
• approach direction and expected body movement
• possible access around, under or over the safeguard
• changes to die height, tooling or production setup

If a person could reach the point of operation before hazardous movement has stopped, the safeguard may not provide adequate protection. Increased separation distance, guard locking, a different access arrangement or another protective measure may be required.

Review Die Setting, Maintenance and Stored Energy

Die setting and maintenance tasks can create some of the highest press risks because guards may be opened, safety devices may be bypassed and employees may work within the point-of-operation area.

The risk assessment should review:

• electrical, pneumatic, hydraulic and mechanical energy
• flywheel run-down and stored energy
• gravity movement of the ram or slide
• die blocks, safety blocks, ram supports or other measures required to prevent unintended gravity or mechanical movement during die setting, adjustment and maintenance
• safe access for die changes
• lifting and handling of dies or tooling
• isolation and verification procedures
• refitting of guards before restart
• testing of relevant safety functions after repair

An emergency stop is not energy isolation. Where personnel are exposed to unexpected movement, stored energy or hazardous press motion during servicing, the appropriate energy-control procedure must be followed.

Consider Automation and Perimeter Guarding

Automated press lines may include robots, transfer systems, coil feeders, conveyors, palletizers and material-handling equipment.

In these applications, modular machine guarding can help control whole-body access to the wider automated cell. Typical measures may include:

• modular perimeter panels
• interlocked personnel gates
• controlled material-transfer openings
• safety-rated protective devices at defined loading points
• impact protection near vehicle routes
• segregated maintenance access

However, modular perimeter guarding does not replace point-of-operation safeguarding at the die area. The press, tooling and local access routes still require machine-specific protection.

Common Risk Assessment Mistakes

Common mistakes include:

• assessing the die area but not the complete press system
• selecting a light curtain without checking stopping performance
• using two-hand controls while leaving side or rear access open
• ignoring access during die setting or scrap removal
• failing to control feed openings and transfer interfaces
• relying on emergency stops instead of proper safeguarding
• bypassing safeguards during setup or fault recovery
• failing to isolate the press before maintenance
• assuming automated feeding removes all point-of-operation risk
• treating perimeter guarding as a substitute for die-area protection

A press guarding arrangement that works only during normal production is incomplete. It must also control foreseeable setup, cleaning, maintenance and recovery tasks.

Relevant Standards and Regulatory Considerations

Press safeguarding should be based on the press type, operating method, risk assessment and applicable local requirements.

Relevant references may include:

• ISO 12100 for machinery risk assessment and risk reduction
• ISO 13849-1 for safety-related parts of control systems
• ISO 13855 for positioning safeguards where approach speed and stopping time are relevant
• ISO 14120 for the design and construction of guards
• ISO 14119 for interlocking devices associated with guards
• ISO 14118 for prevention of unexpected start-up
• ISO 16092 series for safety requirements for presses, where applicable
• applicable ANSI B11 press standards, where relevant to the press type

In the United States, mechanical power presses are subject to OSHA 29 CFR 1910.217, while general machine-guarding and hazardous-energy-control requirements may also apply. In Australia, the AS 4024 Safety of Machinery series addresses risk assessment, safeguarding, safety distances and safety-related control systems.

Local regulatory requirements, manufacturer instructions and machine-specific information should be reviewed before selecting or modifying press safeguards.

Conclusion

Risk assessment for press guarding and point-of-operation hazards must consider more than the visible die area. The review should cover the press, tooling, feeding method, access routes, stopping performance, automation, die-setting tasks and maintenance requirements.

The right safeguarding arrangement prevents or adequately restricts access to hazardous press movement while allowing the task to be completed without unsafe workarounds.

If you are reviewing an existing press, installing new tooling or integrating a press into an automated line, assess the complete system before selecting guards, light curtains, two-hand controls or perimeter fencing. A competent press-safety or machinery-safety specialist can help determine the appropriate safeguarding approach.

Frequently Asked Questions

What is the point of operation on a press?

The point of operation is the area where the press die, ram or tooling performs work on the material. It commonly includes the space between the upper and lower die sections.

What hazards need to be assessed on a press?

Common hazards include crushing, shearing, cutting, trapping, material ejection, flywheel and drive hazards, unexpected cycling, stored energy, feed-system hazards and access during die setting or maintenance.

Are light curtains suitable for every press?

No. Light curtains are only suitable where the press stopping performance, safety distance, control-system design and other access routes have been assessed. They do not protect side, rear or reach-around access unless those paths are separately controlled.

Are two-hand controls enough to safeguard a press?

Not always. Two-hand controls may help keep an operator’s hands away from the point of operation during initiation, but they do not necessarily control other access paths or protect other people near the press.

When is guard locking needed on a press?

Guard locking may be needed where a person could reach the point of operation before press movement or another machine-related risk has ceased. The decision should consider stopping time, access time and the risk assessment.

Does automated feeding eliminate the need for press guarding?

No. Automated feeding can reduce direct operator exposure, but point-of-operation safeguards, access control, drive guarding and safe maintenance arrangements may still be required.

Should press guarding be reviewed after a die change?

Yes. A die change can alter the point of operation, material feed path, guarding position, safety distance and access requirements. The safeguarding arrangement should be reviewed before production resumes.