Can control devices designed to accept a lock be used as the primary isolating device for LOTO?

Control devices designed to accept a lock should not be used as the primary isolating device for lockout/tagout (LOTO) procedures. This is because the primary isolating devices are those that completely and effectively shut off energy to the equipment. While control devices may be fitted to accept locks, they typically do not provide a guaranteed means of isolating the energy, as they may still allow residual or unintended energy flow.

The primary isolating devices must ensure that all potentially hazardous energy sources are de-energized and that the equipment cannot be inadvertently started while being serviced. Acceptable primary isolating devices include circuit breakers, valves, and disconnect switches that are specifically designed for this purpose.

Using control devices as isolating devices could create safety hazards since they may not provide the same level of assurance required for safe maintenance or repair work, thereby increasing the potential for accidents. Therefore, it's critical that trained personnel follow established safety protocols, which specify that only designated isolating devices should be utilized in LOTO procedures.