An 18-year old worker was cleaning a portable mortar mixer when his arm got stuck in it. A painter working near him tried to turn off the machine but the gears would not disengage, so the painter asked for help. A co-worker was finally able to shut off the mixer. Emergency medical services were able to extricate the worker but he was already dead at the scene.
Tragedies like this could have been prevented with proper lockout tagout training in place. Employers are responsible for keeping the workplace safe and providing their employees with the necessary training and PPE. While hazards cannot be eliminated in settings such as a construction site or manufacturing floor, steps can be taken to prevent or mitigate workplace risks. And that is what a lockout tagout (LOTO) procedure is for.
A lockout tagout procedure aims to protect workers from injury risks due to unexpected energization or energy release from equipment and machines while an employee is doing maintenance or servicing on it. This procedure should be part of an entire lockout tagout program.
With lockout, energy is isolated from a machine or equipment using a lockout device. Tagout, on the other hand, is a labeling process whenever lockout is required. This involves attaching an information tag with certain details that must be filled out. To comply with all the applicable LOTO requirements, the LOTO procedure must be performed in line with the following standards:
So what is the purpose of a lockout tagout program? This can help prevent dangerous contact with a machine while it is being maintained or serviced. The program also protects against the machine’s unintended or accidental startup or motion.
The authorized employee is the one responsible for performing the LOTO procedure in a particular piece of equipment. The exact procedure details will depend on the type of equipment in question, but the process must follow the following steps:
All affected workers must be notified that LOTO is being performed. The authorized worker for this task should review the right LOTO procedure for that particular equipment.
If the machine is currently running, the authorized worker must perform the stopping procedure for that machine. There should be detailed and sequential steps that show how to do that.
The authorized worker must be the one to locate and disconnect all of an equipment’s primary energy sources which can be electricity, gas, water, steam, and so on. A good LOTO procedure will feature a detailed explanation, photos, and diagrams for this step.
The authorized worker should install lockout devices on controls and switches. These must be marked with the right tags.
Even though the machine is safely and securely locked, there might be some residual energy left. As such, all elevated and moving assets must be secured, fluids drained, gases vented, and so on.
The authorized person must attempt the normal startup to test whether the machine is properly locked. If the previous steps have been done correctly, nothing should move. After testing, return the controls to off or neutral positions.
The authorized person can now start the required maintenance for that equipment. Scheduled downtime must be kept as short as possible.
The LOTO procedure should feature the steps on how to undo the lockout as well as reconnect all sources of energy. Before removing the LOTO devices, the authorized person should inspect whether the equipment is still intact and double-check that the area is clear. The people who use the equipment should be notified that the LOTO devices have been removed.
This depends on the mistakes that are mostly committed or most likely to be committed while doing LOTO. Keep in mind the general steps for the LOTO procedure and gather data and evidence of noncompliance so that you will know which areas to look at more closely. For maximum safety, a periodic audit of the machine-specific LOTO procedure and staff retraining should be conducted.
Here are some of the most common mistakes in performing a LOTO procedure:
Don’t have a LOTO procedure yet? The US Department of Energy’s SLAC National Accelerator Laboratory created a LOTO procedure template to help you get started with your LOTO program. Download it here:
Here is a sample lockout tagout procedure for a TMC ice machine/walk-in box cooler/freezer: