What is the principal hazard of mushroomed heads on hand-held impact tools?

The principal hazard of mushroomed heads on hand-held impact tools primarily involves the risk of injury from slivers breaking off. When the head of a tool, such as a hammer or chisel, becomes mushroomed—meaning it has been deformed and flattened—sharp edges can form on the surface. These deformations can lead to small pieces, or slivers, breaking off during use, posing a significant safety risk to the user or nearby individuals. If these slivers become airborne, they can cause lacerations or eye injuries.

Although risks like electrocution or decreased effectiveness may be concerning factors in using tools, they are not directly associated with the physical condition of the tool's head. Similarly, while increased wear on the tool can be a consequence of use, the immediate hazard to user safety is more directly linked to injury from slivers breaking off, which is why it is deemed the principal hazard in this context.