Eldon was going to replace the light fixture in his dining room. He turned on the light and then went out to the garage and switched off an electrical breaker. He came back inside to see if the light was off, and since it was still on he went out again and tried another breaker. During one of his trips to the switch box his wife walked through the dining room and switched off the light. When Eldon came back in and saw the light off he proceeded to remove the light fixture.

Fortunately for Eldon he only received a small electrical shock, but it could have been a lot worse. Similar hazards occur at work daily. This is why lockout/tagout should be performed at every workplace and the principles followed at home.

Before we discuss the nuts and bolts of lockout/tagout let's make sure we are all clear on the topic. Some call it LO/TO or LTT (Lock Tag and Try), or simply energy isolation. It isn't important how you title your program, but it is imperative that all companies have a plan in place. If a company is locking out energy sources such as electrical power before working on equipment it is performing a form of LO/TO.

Never assume

LO/TO came into being because employees were being injured by equipment that they assumed was at zero energy. The injuries resulting from not having a LO/TO program can range from a small cut to a fatality.

Paul, Larry and Sam were maintenance men at a chemical company. They had been trained in LO/TO, but they didn't always follow the procedure completely. They were working on a cooling tower fan. Sam was working on the ground level, so he placed his lock on the power source while Paul and Larry went up and got ready to work on the fan motor.

Let's analyze this a minute. If you were Paul or Larry wouldn't you want your own lock on the fan power source to make sure it wouldn't start while you were doing the repair? Actually, Paul and Larry were saving themselves an extra walk up and down the stairs. Paul was in by the fan and Larry was standing near the handrail when Larry saw another worker walking down on the ground. Larry waved hello and when he did Sam thought it was the signal to turn the power back on. Sam took off his lock and the fan motor started automatically. Paul was caught by the moving fan blades and was fatally injured. To save a few steps a worker was lost.

Seven keys to success

Whether your company has a LO/TO program in place or if you are not locking out at all, the following tips and key elements for a successful program can help you reduce injuries:

1) Have LO/TO in place before:

  • service or maintenance is performed on equipment;
  • there is a need to remove/bypass a guard or other safety device;
  • an employee is required to place any body part into an area on a machine or piece of equipment.

2) Perform an equipment review. Inventory all equipment that is affected by an energy source and that may be repaired, cleaned and/or affords an opportunity for an employee to place any part of his/her body into moving parts. Utilize safety committee members or workers from the area to perform this inventory. They are the ones who know the equipment best and will be valuable to your inventory.

3) Categorize the equipment list. Look at each piece of equipment and identify the equipment that puts the worker at the greatest risk. How often the equipment is worked on and the potential for injury will help you make these ratings. For example: A power saw that has to be cleaned each shift would be a high risk. On the other hand, an oil filter that is changed out on a motor once a month would be a lower risk.

4) Develop a lockout procedure. A procedure is needed for each piece of equipment, starting with the highest risk equipment. The lockout procedure can take some time and effort, but it is the backbone of the program.

  • Identify all sources of energy. Electrical power is the most obvious, but all energy sources must be included, such as mechanical, hydraulic, pneumatic, chemical, thermal, gravity or stored energy.
  • As each source of energy is identified you will need to find the best way to control that energy. For example, suppose the equipment that you are writing the LO/TO procedure for is a sulfuric acid pump. You will identify the electrical switch gear that will be locked and the valves that will need to be locked. The power source will normally be one switch box, but there will probably be more than one valve involved in isolating the chemical energy. Typically, you will need to close the inlet and outlet of the pump and open a bleed or drain valve.
  • The next step of the procedure will direct the worker to try the start button of the pump to make sure it will not start. This step is very important because it verifies that the correct electrical power source has been locked. Remember Eldon? If he had tried the light switch when he returned to the dining room he would have avoided the electrical shock.

5) Develop a written program. A complete LO/TO written program includes the roles of all levels of personnel, definitions of the terms, and clear step-by-step procedures to follow when successfully locking out equipment.

6) Provide training. A training program must cover all aspects of LO/TO and include hands-on training on specific equipment.

7) Perform auditing. Regular auditing of the program must be done to ensure that LO/TO is being performed correctly.

Developing a LO/TO program does take some time and effort, but after it is in place the program becomes a natural part of safety.

SIDEBAR: Remember these LO/TO tips. . .

  • Identify all energy sources, and lock and tag them.
  • Only the person who owns the lock can remove the lock.
  • Locks used for LO/TO will only have one key.
  • After locks are applied, the start button must be tried to be certain the equipment will not operate.
  • When the job is complete, the equipment must be checked to make sure it is ready for operation.