Q. Would use of power interlocking guards that prevent motor start up while the guard is removed eliminate the need for locking/tagging out during maintenance or parts replacement?

A. No. The use of interlocked guards to prevent activation of the machine while the guard is not in place, in lieu of lockout or tagout, is permissible only for minor servicing activities which take place during normal production operations. Maintenance and parts replacement take place outside of the normal production process: the machine is turned off, operations stop, a guard is removed, and the maintenance is conducted. Therefore, the provisions of 1910.147(a)(2)(ii) for minor servicing exception does not apply and interlocked guards are no substitute for implementing the lockout or tagout devices. Also, even if the energy source for motor is under the immediate control of the person performing the service and this would limit the risk of an unexpected activation of the equipment, it cannot remove it entirely.