Machine guards, protective devices, safety controls and gates are all part of a system of safeguards used to protect workers from the moving parts of a machine. Too many disabling, and life-changing injuries have happened because of missing or bypassed machine guards. Too many supervisors have had the gut-wrenching task of telling a worker’s family their loved one won’t ever be coming home.
But, it doesn’t have to be that way. These gruesome injuries and deaths can be prevented by simply using the right safeguards, training workers on machine safety, and being diligent when it comes to machine safety.
Name that Safeguard
When it comes to protecting machine operators there are five different options: guards, devices, safety controls, gates, and location or distance.
Guards are physical barriers that block workers’ access to the danger area. There are 4 basic kinds of guards:
- Fixed guards that are a permanent part of the machine;
- Adjustable guards that allow for flexibility in accommodating different sizes of stock;
- Interlocked guards that automatically shut off or stop the machine when tripping mechanism is activated until the guard is put back in place; and
- Self-adjusting guards in which the size of the opening in the barrier adjusts to accommodate the stock, e.g., enlarges to allow larger stock to enter.
Devices automatically stop the machine. The 3 basic types:
- Presence sensing devices that stop the machine’s operating cycle when a light field is broken, e.g., a worker sticks his hand in the danger zone;
- Pullback devices that use a series of cables attached to the operator’s hands, wrists, and/or arms; and
- Restraint devices that only allow the operator’s hands to travel in a predetermined safe area.
Safety trip controls work by quickly deactivating a machine. They include pressure-sensitive body bars and tripwire cables.
Another safety control is a two-hand control which requires both hands and constant pressure on the controls for the machine to operate. This should keep the operator’s hands out of the danger zone.
Gates are simply movable barriers that protect an operator at the point of operation before the machine cycle can be started.
- Gates are, in many instances, designed to be operated with each machine cycle. To be effective, the gate must be interlocked so that the machine will not begin a cycle unless the gate guard is in place. It must be in the closed position before the machine can function.
- If the gate is not permitted to descend to the fully closed position, the press will not function.
Another potential application of this type of guard is where the gate is a component of a perimeter safeguarding system. Here the gate may provide protection not only to the operator but to pedestrian traffic as well.
Location or Distance
Another way to keep operators and other employees safe is by locating a machine in an infrequently used or traveled area or where the dangerous moving parts simply aren’t accessible. If you decide to try this as an option, it’s important that you do a hazard analysis of the machine, situation, and environment first.
What are common requirements for guards?
Machine safeguards must meet these minimum general requirements:
- Stop contact: The safeguard must prevent hands, arms or any other part of a worker’s body from making contact with dangerous moving parts.
- Be sure it’s secure: Workers should not be able to easily remove or tamper with the safeguard.a. This means guards and safety devices must be made of durable materials that will withstand normal use.
b. They must also be firmly secured to the machine if possible – or secured elsewhere if it’s not possible
to attach it to the machine.
- Falling objects: The safeguard should be designed to prevent objects from falling into moving machine parts.
- Say not to new hazards: A safeguard defeats its own purpose if it creates a hazard such as a shear point, a jagged edge or an unfinished surface.
- Don’t interfere: Any safeguard that hinders a worker from performing a job quickly and comfortably might soon be bypassed or disregarded. Proper safeguarding can enhance efficiency because it relieves a worker’s injury apprehensions.
- Safe maintenance: Where possible, lubricating the machine should be done without having to remove the guard. This can be done by putting oil reservoirs outside of the guard, with a line leading to the lubrication point.
How to be a better supervisor
Now that you have a thorough understanding of the different types of machine safeguards and their requirements it’s a matter of being diligent when it comes to:
- Ensuring the machines your workers operate are properly guarded.
- Training workers on machine safety, including associated lockout/tagout procedures for maintenance and guard removal; and
- Enforcing safe work practices and the use of machine safeguards – i.e. taking disciplinary action against any worker that bypasses or removes a guard.
- Advise workers of any potential or actual health and safety dangers and how they can work safely and protect against these dangers.
- Explain how to report machine hazards and other workplace hazards and follow up on all reports.
- Ensure workers comply with OSHA/OHS regulations and use all required equipment, protective devices or clothing required.
- Ensure workers are following lockout and guarding procedures.
- Ensure workers are using or operating machinery in a safe manner.