Machine Guarding Guide (Spanish)

All workplace equipment must be guarded. OSHA guarding standards cover all moving parts on equipment and power tools. There are various types of guarding available to protect employees from harm while operating equipment. While the following are common types of guarding, you should consult the standard that is applicable to the specific machinery in your workplace for more detailed requirements.

Concerns on Any Machine
1. Safeguarding - guard, device, method
2. Controls - control reliability
3. Disconnecting means
4. Starter
5. Covers

When deciding on a guard or device, you must first ask what machinery is in need of guarding. Then, do a risk assessment on the machine and implement engineering controls to reduce employee exposure to the hazard. Lastly, find out the probability of occurrence. This includes the frequency of exposure, probability of injury and how serious an injury would be. Once this is complete, you must decide whether to use a guard or device.

Guards prevent access to the point of operation and include die enclosures and fixed, interlocked, and adjustable guards. These are all items that become part of the equipment and are not to be removed from it once in place.

Devices control access to the point of operation hazards by controlling the operator, machine, or both. Devices include presence-sensing devices, pullbacks, restraints, gates, two-hand controls, and two-hand trip controls. One primary point of operation safeguarding method, guard, or device meets OSHA requirements. Having more than one guarding option gives greater flexibility for multiple setups and human elements. Secondary safeguarding methods may also be required to keep other employees out of an area where hazardous operations take place.

Control Reliability
Control reliability is a way to ensure the integrity of the performance of guards, devices, or control systems. Typically, operations cease and machinery shuts down when controls sense a body part in harm’s way or when an employee opens a door to machinery while it is operating (interlock system).

All new equipment is required to have lockable disconnects. This allows the machinery to be locked or tagged out easily. (See WCF Insurance Safety Topic Lockout/Tag out, for details on lockout procedures.)

All start buttons should have a ring guard around them to protect from accidental startup. Accidental start-ups can potentially cause injury to operator and others.

All moving belts, gears, fans, chains, and pulleys should be guarded up to seven feet from the working platform level.

An employee's fingers should not be able to fit through openings in the cover. Openings should be no more than 1/2 inch in diameter for expanded metal.

Common Machines and Guarding Requirements
Bench Grinders: On bench grinders, the tongue (top of grinder) guard should have no more than 1/4-inch opening between the wheel and the guard. There should also be a tool rest at the bottom of the grinder and the opening must be no more than 1/8 inch. A cover is required on the exterior of the grinder to protect an employee in the event of wheel shatter.

A ring test should also be done prior to placing a wheel on the grinder. Hold or suspend the wheel in the air using twine or rope and, using a hard non-metallic object, tap the wheel. If you hear a ring sound, the wheel is safe. If there is a dull sound, the wheel is cracked and should not be used. Performing this simple test can prevent a very serious injury. Proper guarding on bench grinders prevents serious injury, and possibly death, in the event of wheel breakage. Make sure the RPM on the new wheel matches the RPM of the grinder.

Presses: All presses should be part revolution types. This allows the operator to stop the process mid-cycle if necessary. Full revolution operations machinery must complete the cycle before it can be stopped. Since it cannot be stopped immediately, employees are in danger of serious injury such as limb amputation.

Guards available for presses include barrier guards, two-hand control, two-hand trip, foot controls, and gates. Other types of guarding methods include distance, hand tools, and pullbacks. The type of guarding used depends on the function of the equipment and what the best method is to protect employees.

Other guarding issues should be addressed for hand held tools, lathes, and drill presses. The key to machine guarding is protecting employees from harm while allowing the equipment to perform properly. Allowing employees to bypass or remove guards compromises safety and should not be allowed. There are many types of guards available for every type of equipment in the workplace.

Consult the OSHA 1910 standards for the specific type of equipment used in your workplace.
1910.211 - Definitions
1910.212 - General requirements
1910.213 - Woodworking machinery
1910.214 - Cooperage machinery
1910.215 - Abrasive wheel machinery
1910.216 - Mills and calendars
1910.217 - Mechanical power presses
1910.218 - Forging machines
1910.219 - Mechanical power-transmission apparatus

Additional Resources
WCF Insurance Safety Department
(385) 351-8103

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NOTICE: This guide may make reference to the Occupational Safety and Health Administration (OSHA) regulations; however the guide is not legal advice as to compliance with OSHA or other safety laws, codes, or regulations. Compliance with OSHA and other safety laws codes or regulations, and maintaining a safe work environment for your employees remains your responsibility. WCF Insurance does not undertake to perform the duty of any person to provide for the health or safety of your employees. WCF Insurance does not warrant that your workplace is safe or healthful, or that it complies with any laws, regulations, codes, or standards.