PMPA member companies are engaged in making parts that require precision machining. This necessitates multiple, routine adjustments throughout a shift.
These adjustments can include changing a dulled drill bit on a screw machine or an insert on a CNC machine. It might involve redirecting a coolant line that vibrated out of place. Or, it can be adjusting the alignment of a tool multiple times to maintain the needed offset or location.
These kinds of adjustments are routine, repetitive and integral to the use of the equipment for production. They are necessary so that the parts are produced to the required precision.
This is the classic type of situation that was intended to be addressed by the exception to the Lockout Tagout (LOTO) standard 1910.147(a)(2)(ii)(B). This exception assumes the worker performs the maintenance using alternative measures that provide alternate protection. Still, many inspectors do not recognize the exception to the LOTO requirements.
According to interpretations published on the OSHA website, “…minor tool changes and adjustments, which are routine and repetitive and must be performed as an integral part of the production process, are permitted to be performed without LOTO if the work is performed using alternative measures that provide effective protection.”
One form of effective protection is stopping the machine using an electric disconnect or control switch (not an energy-isolating switch). This is only allowable if the switch is: 1) designed and applied in accordance with good engineering practice; 2) controls all of the hazardous energy and is placed in the off position; and 3) is under the exclusive control of the employee performing the task.
Additional support for the exemption can be found in this quote from the Federal register Vol. 54, No. 169, Friday, September 1, 1989: “As was discussed in the preamble to the proposal, OSHA recognizes that some servicing operations must be performed with the power on; in these situations, it would not make sense to require lockout or tagout, which apply to deenergized equipment.”
In summary, minor servicing or maintenance that is routine, repetitive and integral to the use of the equipment for production may be covered by alternative protection. This protection includes electric disconnect or control switches that meet the aforementioned requirements.