In 2014, the Occupational Safety and Health Review Commission (OSHRC) issued a judgment on an OSHA case, and in the case, they made it clear that “magnitude” matters in lockout/tagout (LOTO). But for some reason, this piece of data is absent from many machine-specific LOTO procedures and OSHA always takes issue with this oversight. So where is “magnitude” required in LOTO?
1910.147(c)(7)(i)(A) Each authorized employee shall receive training in the recognition of applicable hazardous energy sources, the type and magnitude of the energy available in the workplace, and the methods and means necessary for energy isolation and control.
and in
1910.147(d)(1) Preparation for shutdown. Before an authorized or affected employee turns off a machine or equipment, the authorized employee shall have knowledge of the type and magnitude of the energy, the hazards of the energy to be controlled, and the method or means to control the energy.
(d)(1) has always been read to require:
- the energy type (electric, pressure, chemical, hydraulic, gravity, etc.)
- the magnitude of each energy source (volts, psi, weight, temp, etc.)
This magnitude information can be CRITICAL when selecting the energy isolation device(s). In most cases, when the isolation device is built into the process, such as an electrical disconnect or a valve, it is easy since these devices are clearly rated for the magnitude of the energy they see. Where magnitude can get tricky when we use blinds as an isolation device for a pipe associated with entry into a PRCS.
It should be obvious that we need a blind with at least the rating of the pipe/flange where it will be installed. An engineer may be able to find the pipe/flange rating, but an operator or mechanic may not readily find the pressure rating of the piping. This could lead to a blind rated at 50 psi installed on a pipe run rated for 500 psi. Do we think a blind rated for 50 psi will function as needed when it sees 500 psi? Magnitude matters in LOTO!