OSHA Machine Guarding – 29 CFR 1910.212

Machines make countless workplace tasks faster and more efficient, but moving parts can cause severe injuries when employees can reach or come into contact with them. Crushing, cutting, shearing, entanglement, amputation, and struck-by injuries can occur in a fraction of a second.

OSHA’s general machine guarding requirements are found in 29 CFR 1910.212. OSHA requires one or more methods of machine guarding to protect operators and other employees from hazards created by points of operation, ingoing nip points, rotating parts, flying chips and sparks, and other dangerous machine movements.

Machine guarding may involve physical barriers, interlocks, presence-sensing devices, two-hand controls, and other safeguarding methods appropriate for the machine and hazard.

Where Machine Hazards Occur

A machine does not need an exposed blade to create a serious guarding hazard. Injuries can occur anywhere moving equipment creates a dangerous point of contact.

Three areas are especially important when evaluating machinery:

Point of Operation
The point of operation is the area where work is actually performed on the material, such as cutting, drilling, punching, bending, shaping, or forming.

Power-Transmission Components
Belts, pulleys, chains, sprockets, gears, shafts, couplings, flywheels, and similar components transfer energy through a machine and can create entanglement, crushing, and pinch-point hazards.

Other Moving Parts
Rotating, reciprocating, and transverse-moving components can also expose workers to hazardous motion.

Common Machine Motions and Actions

Understanding how a machine moves can help identify where injuries are most likely to occur.

Rotating motion can catch clothing, hair, gloves, or body parts and pull a worker into machinery. Shafts, spindles, couplings, and rotating tools are common examples.

Reciprocating motion involves back-and-forth or up-and-down movement that can create crushing or shearing hazards between moving and stationary components.

Transverse motion occurs when a machine component moves in a straight, continuous line and may create pinch, shear, or caught-between hazards.

Machine operations may also create hazards through:

• Cutting.
• Punching.
• Shearing.
• Bending.
• Forming.
• Flying chips, sparks, or material.

Point-of-Operation Guarding

The point of operation is where work is performed on the material being processed.

OSHA requires the point of operation to be guarded whenever operation of the machine exposes an employee to injury.

Where a specific machine standard does not establish another guarding method, the safeguard must be designed and constructed so the operator cannot place any part of the body in the danger zone during the operating cycle.

Machines commonly requiring point-of-operation guarding include:

• Guillotine cutters.
• Shears.
• Alligator shears.
• Power presses.
• Milling machines.
• Power saws.
• Jointers.
• Portable power tools.
• Forming rolls and calenders.

Other machines may also require point-of-operation guarding whenever their operation exposes employees to injury.

What Is a Machine Guard?

A machine guard creates a physical barrier between an employee and a hazardous area of machinery.

OSHA requires guards to be affixed to the machine where possible. When attachment to the machine is not possible, the guard must be secured elsewhere.

A guard must also be designed so that it does not create an accident hazard itself.

Effective safeguards should prevent employees from contacting hazardous moving parts while allowing the machine to perform its intended function.

Fixed Guards

A fixed guard is permanently attached to the machine and does not depend on moving parts to provide protection.

Fixed guards are commonly constructed from metal, screening, bars, plastic, or other durable materials.

Because they provide a physical barrier that normally remains in place, fixed guards are one of the simplest and most common methods of preventing access to hazardous machine components.

Interlocked Guards

An interlocked guard is connected to the machine’s operating or control system.

Opening or removing the guard causes hazardous operation to stop or prevents the machine from operating while the guard is open.

Closing or replacing an interlocked guard should not, by itself, cause the machine to automatically restart.

Interlocks should never be bypassed or defeated in a manner that exposes employees to hazardous machine movement.

Adjustable Guards

Adjustable guards can be repositioned to accommodate different sizes or shapes of material while continuing to provide a barrier between the employee and the machine hazard.

Because their effectiveness depends partly on their position, they must be properly adjusted for the material and operation being performed.

An improperly positioned adjustable guard may leave enough of an opening for an employee to contact the hazard.

Self-Adjusting Guards

A self-adjusting guard changes position as material enters the machine.

The material moves the guard only enough to pass through the opening, and the guard returns toward its protective position as the material passes through or is removed.

These guards are commonly associated with equipment where different sizes of material must pass through a guarded area.

Guards Aren’t the Only Safeguards

Physical guards are only one method of machine safeguarding.

Depending on the equipment and operation, protection may also involve:

• Presence-sensing devices.
• Two-hand controls or trips.
• Gates.
• Restraint devices.
• Pullback devices.
• Safeguarding by location or distance.
• Other protective devices or systems.

The appropriate method depends on the machine, its operation, employee interaction with the equipment, and the specific hazard being controlled.

Hand Tools Are Not a Substitute for Guarding

Special hand tools may sometimes be used to place or remove material from a point of operation without requiring an employee’s hands to enter the danger zone.

However, OSHA specifically states that these tools cannot be used instead of required machine guarding.

They may supplement the protection provided by guards or safeguarding devices, but they do not eliminate the requirement to guard the hazardous point of operation.

Revolving Drums, Barrels, and Containers

OSHA establishes a specific guarding requirement for revolving drums, barrels, and containers.

These machines must be protected by an enclosure that is interlocked with the drive mechanism so that the drum, barrel, or container cannot revolve unless the guard enclosure is in place.

This prevents employees from being exposed to hazardous movement while the enclosure is open.

Fan Blades

Exposed fan blades can create cutting and amputation hazards.

Under 29 CFR 1910.212, when the periphery of a fan blade is less than 7 feet above the floor or working level, the blades must be guarded.

The guard must have openings no larger than ½ inch.

Anchoring Fixed Machinery

Machines designed for a fixed location must be securely anchored to prevent them from walking or moving during operation.

Movement caused by vibration or operating forces can affect machine stability, alignment, guarding, and employee safety.

Grinders, buffers, and other fixed-location machinery should therefore be properly secured to an appropriate supporting structure, with the overall installation preventing hazardous movement.

Machine Guarding and Maintenance

Machine hazards can change when equipment is being cleaned, adjusted, repaired, unjammed, serviced, or maintained.

A guard that normally protects an operator may need to be removed to gain access to internal machine components.

When servicing or maintenance exposes an employee to unexpected startup, energization, or release of stored energy, OSHA’s lockout/tagout requirements under 29 CFR 1910.147 may also apply.

Machine guarding and lockout/tagout address related but different hazards:

Machine guarding primarily protects employees from hazardous machine components and processes during normal operation.

Lockout/tagout controls hazardous energy during covered servicing and maintenance activities.

Employers must determine which requirements apply to the particular task.

Machine-Specific OSHA Requirements

Section 1910.212 establishes general requirements for machinery, but some equipment is also subject to more specific OSHA standards.

OSHA’s Machinery and Machine Guarding standards in 29 CFR 1910 Subpart O include requirements covering equipment such as:

• Woodworking machinery.
• Abrasive-wheel machinery.
• Mills and calenders.
• Mechanical power presses.
• Forging machines.
• Mechanical power-transmission apparatus.

Employers should evaluate both the general machine guarding requirements and any machine-specific OSHA standard that applies to the equipment being used.

Preventing Machine Guarding Injuries

Effective machine guarding begins by identifying where employees can encounter hazardous movement.

Employers should evaluate points of operation, power-transmission components, rotating and reciprocating parts, nip points, cutting surfaces, flying material, and other machine hazards.

Guards and safeguarding devices should remain properly installed, secured, functional, and appropriate for the operation. Employees should never remove, bypass, defeat, or alter safeguards unless the work is performed under procedures that provide the protection required for the task.

Machine safeguarding works best when it is treated as part of the equipment’s normal operation rather than as an obstacle to production.

For additional regulatory information, see OSHA 29 CFR 1910.212 – General Requirements for All Machines and 29 CFR 1910 Subpart O – Machinery and Machine Guarding.

For company-specific requirements covering responsibilities, inspections, machine safeguards, guard removal, maintenance, training, and safe-work procedures, refer to the company’s Machine Guarding Program.