Why do we need guarding?
The most important reason to make a workplace safe is to make sure that at the end of a shift, employees are able to go home safely. Guarding is put in place to protect workers and separate them from moving machinery. This results in increasing safety, while decreasing the chance of an accident. It is also the right thing to do, as it shows the workers that management cares about their safety and is willing to carry out necessary requirements to keep them safe.
Guarding will also decrease liability from any possible accidents that may occur and is regulated by governing bodies. MSHA and OSHA have their own guarding requirements, which would not be in place unless something had happened to make them necessary. Guards are meant to protect personnel from inadvertent, careless or accidental contact and deliberate or purposeful work-related actions. These include inspection, testing, cleaning, maintenance, troubleshooting, lubrication, adjustment and servicing. Guards are not meant to protect personnel from deliberate or purposeful non-work-related actions.
Setting the guarding policy
When establishing a guarding policy, use the current MSHA or OSHA guarding standards. It should be implemented by the owner or management in collaboration with the workers and the joint health and safety committee. A good tool to use for standardisation of a guarding policy is the ‘American National Standards Institute (ANSI) B11 – Safety Series Standards for Machine Tools.’ This guideline was developed to determine guarding mounting distances based on the maximum opening sizes in the guarding. It ensures that any body part that can fit through the mesh will not be able to contact the rotating or moving component inside. All personnel should be involved in the planning and implementation process so everyone understands why the guarding is necessary.
Identifying danger areas
Using a safety gauge can help determine the distance from a hazard. The safety gauge is a tool to describe how a pinch point is measured and how the barrier opening size affects the distance from the hazard. The goal is to keep all objects away from exposed rotating parts, where the object can be pulled in and damaged. These parts include shafts, drums or return rollers. The in-running pinch point plus the entire exposed area of the rotating or moving component can be considered the danger area. Even the exposed area of the component, if burred or if there is buildup or wear, can create an entirely separate hazard. A worker should not be able to reach in or around any moving components. A safety gauge will give a clear indication as to whether or not the guarding is adequate and meets requirements, or if insufficient guarding needs to be replaced.
How danger areas can change over time
Much like the environment, danger areas can change over time due to various condition and element changes. For example, a return roller could get worn and have a hole in the can or pick up other material, which would cause the entire return roller to become the danger area. The lagging on a pulley starts to loosen from the steel can, or the can is able to wear through.
Things to consider when building a guard or guarding an area
There are several important factors to selecting a guarding solution:
Ease of maintenance and cleanup
Make sure the guards are maintenance- and cleanup-friendly. A guard that is hard to maintain or clean can cause major problems later if the workers have a difficult time performing their duties.
Special requirements for the area being guarded
Things such as lubrication, vibration analysis, heat analysis, speed sensing, overheating concerns, corrosive areas and flammable areas all need to be taken into consideration before selecting a guarding solution.
A well-designed guard should not weigh more than 50 lb. and should not require more than one person to remove or install it.
The guard should be designed to fit into place easily with minimal thought or effort; simplicity is an important factor when dealing with a wide variety of workers who may come in contact with the guard.
Ability to withstand normal operational forces
Guarding does not need to be able to withstand catastrophic failures, such as if a shaft breaks or a wheel flies off, but it should be able to endure everyday forces; for example, if an employee puts his/her weight on the guard, it should be able to support him/her.
A quality fastening system
A fastening system is required to ensure the guard remains securely in place while the machine is being operated. A wedge clamp is a very simple option, as it is never removed so the guard always has a place to go back on to. As an alternative, a tie wrap can be used to comply with MSHA standards that require a tool to remove.
The guarding solution should be easily recognisable. One way to heighten guard visibility is to paint the guards a colour that will stand out from the equipment. If colours are standardised, the employees will recognise which colour means danger. Safety yellow is the most common coloir used to identify guarding.
Adjustability and ease of inspection
The guards should be able to be adjusted without the loss of protection and without modifications to the guard itself. They should also be able to allow for inspection without removal, or the company should have a policy in place to ensure the guard is never removed while the equipment is in operation.
The design, material and construction of the guard should enhance the equipment it protects against, not create further hazards. Guards should be free of burrs, sharp edges and pinch points. Hand railings, for example, are often used where guarding should be. However, hand railings can be breached easily and are not adequate protection to limit access to a pinch point.
Guarding equipment should be an essential element of worker safety. When choosing a guarding solution, keep it simple; the less complicated the guard is, the easier it will be to access the equipment and perform maintenance. Standardised guarding will create uniformity and familiarity for those working around it. Training should also take place to ensure personnel understand why the guarding is in place and why it is critical to keep the guards in place. Finally, ensure the worker does not come in contact with any rotating or moving machinery.
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