Safeguarding machinery to prevent injuries
Generally speaking, every type of industrial machinery can be broken down into three basic elements, each of which may include many parts. First, there’s the point of operation, which is the location where the machine’s primary function is performed. Second is any part of the power transmission process, which connect the source of energy to the components that actually perform the work. Finally, there is normally some type of mechanical or electrical control that governs the operation of the machine.
The movement of machines and their component parts can create hazards to workers who are using the machinery or who are in close proximity. In addition to dangers presented at the point of operation, where the machine performs the cutting, bending, or other actions for which it was designed, hazards are also presented by the movement of any components, as well as by locations that provide pinch or shear points at which body parts or clothing could become trapped between moving and stationary elements.
Depending on the nature of the machinery, contact with those moving parts can lead to a long list of serious injuries, including amputations; crushed fingers, hands, or feet; damage to the face and eyes; or skin damage such as burns.
Types of safeguards
To reduce the potential for such injuries, any part of the machinery that presents a hazard must be addressed. If the hazard cannot be eliminated or controlled through engineering, the area presenting the problem must be safeguarded. Strategies for safeguarding workers can be divided into five broad types:
- Physical guards, which are barriers that are either constructed as part of the machine or added to it. Some guards are fixed, permanent parts of the machine, designed to be strong enough to keep workers from coming in contact with moving parts and prevent any debris ejected by the moving parts from reaching the workers. Some guards are designed in an interlocking manner, in which removing or opening the guard prevents the machinery from operating. Workers must secure the guard in place before resuming work. Some guards can be adjusted to accommodate different tasks or workpiece sizes, whether they adjust automatically or require manual changes.
- Changing location, in which the machinery or the moving parts are relocated to ensure they are at a safe distance from the workers’ location.
- Feeding/ejection mechanisms, which automate the process of inserting materials in the machine and/or removing the finished product, eliminating the need for workers to have direct contact with the moving parts.
- Safeguarding devices, which encompass a variety of equipment that prevents or limits access to the hazards. These can include everything from controls that require the worker to use both hands, gates that block access to moving parts, and sensing devices that identify when the worker is too close to the hazard.
- Other aids include equipment such as shields and barriers, and tools the worker can use to push materials into the machinery or safely hold it in place while operations are being performed.
No matter which type of safeguarding strategy is employed, it needs to assure worker safety in several ways. First, it must prevent workers, their extremities, and their clothing from coming in contact with any moving parts. It should also ensure that nothing can inadvertently be dropped into those moving parts. A tool or even something as small as a fastener could either cause damage to the machinery or be flung out as a projectile.
The safeguard cannot create new hazards. When designing a guard to protect workers, care must be given to ensure the guard doesn’t present any sharp edges, new pinch points, or other elements that could lead to injuries. It also should not interfere with the workers’ ability to perform their tasks or properly lubricate and maintain the equipment. Safeguards must also be designed in ways that prevent workers from removing them or otherwise tampering with them in ways that interfere with their effectiveness. They should also be sturdy enough to stand up the rigors of the task and the environment.
Safe work practices
Machine safeguards are an important component of assuring worker safety, but they’re only one element of a comprehensive approach. Workers must always wear the appropriate personal protective equipment (PPE) for the task and the nature of that machine, whether that’s goggles, a face shield, gloves, or other options. While the machine may have built-in safeguards, the added layer of protection may be needed to protect workers from debris and other objects.
Workers must also stay focused on the task being performed when machinery is operating. They cannot be distracted by other tasks or other workers. They should also stand clear of areas in which materials are loaded into or removed from machinery except when performing those actions.
Finally, another element of safeguarding workers is a robust lockout/tagout program to ensure that people who are working on or otherwise maintaining machinery are protected from it being accidentally energized.
Training matters, too
As with every other aspect of workplace safety, it’s critical that workers receive adequate training in issues related to machine safeguards. Workers need to have a complete understanding of how the machinery works, the hazards it presents, and how the safeguards protect them. They must be aware of any circumstances under which safeguards might be disabled or removed and who has the authority to do so, and what steps they should take if they discover that a safeguard is damaged or inoperative. Thorough hands-on training will ensure all the other efforts involved in protecting workers from dangerous encounters with machinery will be as effective as possible.