LOTO (Lock Out Tag Out)

There are 8 main steps to the LOTO procedure. The first step is to notify affected employees that the equipment will be shut down and undergoing repairs or maintenance. Next, you want to identify the procedures and hazards of the work, especially because the hazards can vary across electrical, hydraulic, or thermal energy sources. Hazards can also vary in their magnitude and the way they can be controlled. The third step is to shut down the equipment and isolate the energy source from the machine, keeping in mind the equipment hazards, components, and shutdown procedures. Verify that the power is off. Then, you apply your LOTO devices.

LOTO devices consist of locks or tags. In cases where you apply a physical lock, the idea is that nobody can open it without the key—and only the person(s) working on the equipment should have the key(s). These locks can vary, consisting of traditional locks and straight-line locks with bits at the end. When you’re working on machines with multiple circuits, you may have to lock out more than one point. It’s also a good idea to have written instructions and records related to lockouts so that superintendents and other people on the job site understand what to do during a lockout/tagout situation and why it’s going on.

You must also tag out the equipment to notify people in the area that someone is working on the equipment. Tags should also include the name of the person(s) who locked or tagged the equipment out. These tags often explain why the equipment is being shut off and when normal operation can be expected to resume.

After locking/tagging the equipment out, you will want to verify that all stored energy has been released. In electrical systems, you want to make sure that there is no voltage behind the system. Other systems could have pressurized contents that could cause injury, so that blanket term covers hydraulic, thermal, etc., systems. In the case of electrical systems, you will want to check for voltage from leg to leg and from leg to ground. The equipment should also not turn on once the power has been isolated.

Once you’ve verified that stored energy has been released, you will also want to ensure that you have an arc flash kit and a fire extinguisher at your disposal. (ABC fire extinguishers are standard for general use, though electrical fire extinguishers can be good for electrical applications.) Arc flash kits include a face shield, safety glasses, safety gloves, and fire-resistant clothing.

When it’s finally time to bring the equipment back online after you’ve done your repair or maintenance procedure, you will want to start by clearing the area. Once you remove the LOTO kit, you can bring the breakers back on and then re-energize the equipment. Then, once you successfully start the equipment up again, verify that the machine or system is working properly.

Over time, LOTO procedures may change. OSHA provides the main framework for LOTO, but individual companies can adjust procedures that aren’t explicitly provided by OSHA. It’s the responsibility of company leaders to communicate changes to the company policies, reinforce the rules in place, ensure that workers have the proper PPE, and call out improper use of LOTO.