When is a lock-on switch permissible on a power tool?

A lock-on switch on a power tool is permissible when it can be turned off with a single finger motion because this design prioritizes safety and operational control. This feature allows the operator to maintain control of the tool's power while working, especially during extended tasks, without requiring continuous pressure on the switch. The ability to shut off the tool quickly with minimal effort enhances safety in case of emergencies or sudden changes in the working environment.

Other options do not align as closely with safety standards. For instance, a lock-on switch is not simply allowed based on two-handed operation, as this could lead to situations where operators may struggle to disengage the tool quickly. While trained personnel may know how to handle a tool properly, safety features should not rely solely on the operator’s skill levels. Lastly, manufacturer indications can help guide the use of a lock-on switch, but the critical factor remains the ability to turn off the switch swiftly and readily, which is essential for preventing accidents and maintaining a safe working environment.