Machine Guarding and Power Tool Safety

Published On: February 17, 2023By Categories: Safety, Safety Matters

It is critical that best practices are always followed when using machinery and tools on the job.

By Alexandra Walsh

Crushed hands and arms, severed fingers, and blindness are just part of a list of possible machinery- and tool-related injuries.

A good rule to remember is any machine or power tool part, function, or process that may cause an injury must always be safeguarded. When operating machines and power tools, an accidental contact with and even simply being in the vicinity of machines and tools in operation can create workplace hazards that must be controlled or eliminated.

Machine Guarding

According to OSHA, employee exposure to unguarded or inadequately guarded machines is prevalent in many workplaces. As a consequence, OSHA notes that workers who operate and maintain machinery suffer close to 18,000 amputations, lacerations, crushing injuries, and abrasions—and more than 800 deaths per year.

OSHA further points out that amputation is one of the most severe and crippling types of injuries in the occupational workplace, and often results in permanent disability.

Supervisor Responsibilities

Supervisors should ensure that the following requirements are met:

  • Employees receive training in machine guarding.
  • No modifications are made to machine guards without the manufacturer’s prior approval.
  • Employees are prevented from removing manufacturer-provided guards from any piece of equipment.
  • Damaged or unprotected equipment is removed from service.
  • Machines and machine guarding devices are periodically inspected.
  • All safety equipment is maintained.
  • Only qualified and trained employees operate equipment.

Employee Responsibilities

Employees should be held responsible for:

  • Attending machine guarding training
  • Operating and maintaining machine guards in a safe manner according to training
  • Reporting all machine guarding issues to the supervisor
  • Following lock out/tag out procedures.


A machine should never be left unattended with the control switch in the “On” position. Also, no blades, cutter heads, or collars should be placed or mounted on a machine arbor unless it has been accurately sized and shaped to fit the arbor.

If blades are dull, badly set, improperly filed, or improperly tensioned, they should be immediately removed from service. Sharpening or tensioning saw blades or cutters must be done only by qualified employees.

Electrical Safeguards

All machinery must be installed according to the National Electric Code (NEC) and to the manufacturer’s requirements. If machines have exposed non-current-carrying metal components, they have the potential to become energized and should be grounded.

Control switches should be available to employees at their operating positions, so they don’t need to reach over moving parts of machinery. Also, machine controls must not be wedged for continuous operation.

Machines that are not adequately safeguarded to protect the employee during an under-voltage situation or a power failure must have an under-voltage protective device installed. This device prevents the machine from starting up after a power interruption is over, which in some cases could expose the employee to the danger of moving parts.

Before performing maintenance or major adjustments to moving parts that require panels and guards be removed, all machine energy sources or energy isolating devices must be locked out or tagged out.

According to OSHA, employee exposure to unguarded or inadequately guarded machines is prevalent in many workplaces.

Maintenance Requirements

Qualified employees should adhere to the following safety protocols during the routine maintenance of machine guards and machinery:

  • Lock and tag out power supply prior to repairing the guard.
  • Use only replacement parts equivalent with those in the original design.
  • Do not alter the guard or guard parts.
  • Do not add any parts not supplied by the manufacturer nor delete any parts supplied by the manufacturer.
  • Keep the machine and its guards in clean and safe operational condition.


A planned inspection and maintenance program should be consistent with the machine manufacturer’s recommendations. Only trained and qualified employees should be permitted to inspect, maintain, and repair machine guards in accordance with the manufacturer’s specifications. No repairs should be made unless the machine is locked out.

Care and Use

Most machine guards are designed to be fixed to the machine. These guards must not be removed unless authorized by the manufacturer or by a qualified employee. Machine guards should be removed if they are designed to be removed for cutting device changes or to make small cuts. Only qualified repair operators should remove all other guards.

Any irregularities in the operation of machine guards should be immediately reported to the supervisor. Malfunctioning machine guards affect the safe operation of machinery and will render the machine unfit for service until the irregularities are corrected.

If at any time a machine guard needs repaired, or is defective or unsafe, remove the machine from service until its guards have been restored to a safe operating condition. Place an “Out of Service Tag” on the machine and labeled with the employee’s name, date, and a description of the problem. Provide this information to everyone on the team.

New and Rented Equipment

Prior to first-time use, all new or rental machines should be inspected by a qualified employee to ensure compliance with the provisions of the company safety program. For new equipment, an initial inspection will verify that the equipment is suitable for its intended use. All machines should meet the design and construction requirements identified in general industry standards.

Power Tool Safety

Power tools help workers easily perform tasks that otherwise would be difficult or impossible. However, these simple tools can be hazardous and have the potential for causing severe injuries when improperly used or maintained.

All hazards involved in the use of hand and power tools can be prevented by following five basic safety rules:

  • Keep all tools in good condition with regular maintenance.
  • Use the right tool for the job.
  • Examine each tool for damage before use.
  • Operate the tool according to the manufacturer’s instructions.
  • Provide and use the proper protective equipment.

Employees who use power tools and are exposed to the hazards of falling, flying, abrasive, and splashing objects or exposed to harmful dusts, fumes, mists, vapors, or gases must be provided with the particular personal equipment necessary to protect them from the hazard.

Safety Precautions

Supervisors should provide training and observe employees’ work motions while on the job to verify that they understand the proper way to safely use power tools.

Power tools must be fitted with guards and safety switches. They are extremely hazardous when used improperly. Exposed moving parts of power tools—belts, gears, shafts, pulleys, sprockets, spindles, drums, flywheels, and chains—must be guarded.

Employees using electric tools must be aware of several dangers. Among the most serious hazards are electrical burns and shocks.

To prevent hazards associated with the use of power tools, workers should observe the following general precautions.

  • Follow the instruction manual before using any power tool.
  • Always wear safety goggles or glasses with side shields.
  • Use a respirator for dusty operations or where other respiratory hazards may be present.
  • Wear hearing protection where there are high levels of noise.
  • No loose-fitting clothing, jewelry, or dangling objects should be worn.
  • Long hair must be tied back.
  • Training is required on the use of each tool prior to use.
  • Tools that have been damaged or are unsafe must be tagged out of service.
  • Avoid carrying the tool by the electric cord.
  • Work area must be free of any debris that could be ignited by hot tools, chips, or sparks.
  • Make sure the power switch is off before plugging in the power tool.
  • Check that all appropriate tool guards are in place and working.
  • Keep cords away from sharp edges, heat, and other hazards.
  • Properly clean and store tools that are not in use.
  • Secure all tools that have sharp blades or edges.
  • Turn off and unplug the tool before making any adjustments or changing accessories.
  • Only use accessories specifically supplied or recommended by the manufacturer.
  • Never use power tools in wet or damp conditions.
  • Never use a tool that is damaged or malfunctioning in any way.
  • If the tool has a three-pronged plug, make sure a three-pronged extension cord is plugged into a three-pronged outlet.
  • Make sure cutters or blades are clean, sharp, and securely in place and never use bent, broken, or warped blades or cutters.
  • Stay focused while operating.
  • Always keep a firm grip with both hands.
  • Warn anyone in close proximity to move to a safe distance.

Remember, any power tool with moving belts, pulleys, chains, drums, gears, spindles, and other rotating or moving parts must be equipped with safety guards. Equally important to remember is those safety guards must never be removed so safety can always be at the forefront of what you do.

Alexandra Walsh is the vice president of Association Vision, a Washington, D.C.–area communications company. She has extensive experience in management positions with a range of organizations.

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