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Machine Guarding
Keeping Mistakes from Becoming Accidents

The only sure way to prevent machine accidents is to install foolproof guards which make injuries impossible.  Several common methods of guard­ing are described below, with the best ones listed first:

• Enclosure guards. A worker can­not get caught in a machine if the dangerous parts are completely en­closed.  Guards can be designed with an opening which is wide enough only to let the work materials through.  If a guard is adjustable for different sizes of material, the safety committee should insist that the guard doesn't allow hands to get near the danger area.
• Interlocking guards. A work area can be set up so that the equipment does not operate unless all workers are out of the danger zone.  Under some systems, a gate or barrier must be closed before the machine can be turned on.  Other systems use an electrical con­tact, mechanical stop, or electric eye beam to shut off the machine if any part of a worker's body enters the danger area.
• Two handed controls. If ma­chines can be designed so that the operator needs both hands to turn on switches, valves, or levers, the worker cannot easily start the machine by accident or have a hand in the machine when starting it.
• Panic bars. Pressure-sensitive bars will turn off a machine whenever someone leans against the bar. These can be used both to prevent accidents and to give workers a way to turn off a machine if an accident occurs.

Often, guards are available but are removed or not used. The safety committee should encourage man­agement to design guards which pro­vide protection without interfering with the work, if that is possible. Guards are more likely to be left on if they don't have to be removed for com­mon maintenance tasks such as lubri­cation.  If guards must be removed for main­tenance or to fix a jam-up, the equipment be locked out during that time.

When checking for proper guard­ing, you should ask questions such as these:

• Are the operators' hands, bodies, and fingers out of the danger area when a machine is being operated? If not, what type of guard could be installed?
• Are starting and stopping controls within easy reach of the operator?
• Are belts, pulleys, chains, sprock­ets, gears, and saw blades properly guarded?
• Are rotating parts covered or out of reach inside the equipment?
• Are fans that are located near the floor guarded?
• Are guards firmly attached so that they are not easily removed?
• Are abrasive wheels covered with strong guards?
• Have operators been trained in why and how they should use and maintain guards?
• If operators are not within sight or hearing of other workers, is an alarm device provided to call for help if there is an accident?
• Is the employer following all fed­eral and state OSHA requirements for machine guarding and special rules for guarding of hand and portable pow­ered tools?
• Is there an effective system to disconnect and lock out the machine from its power sources if guards must be removed so maintenance can be performed?

Courtesy of TheWorkSite.org.