Lockout and Tagout (LOTO) Procedures

System Operation

When performing maintenance, doing repair work, or when a machine is in an unsafe state, it is vital to eliminate the possibility of the machine moving unexpectedly. Maintenance or repairs on process piping or working with electrical equipment might put a worker at risk of an accidental release of energy.

Precautions employed to eliminate these hazards are called lockout or lock-off procedures. Simply locking off the electrical power or closing a valve is not necessarily enough.

A systematic and thorough knowledge of the system and work to be performed is necessary before you can implement any lockout procedure.

WorkSafeBC regulations and lockouts

De-energization and lockout procedures are described in Part 10 of the Occupational Health and Safety (OHS) Regulation.
Note that:

• You must use your own locks and keys.
• You must not borrow another person's lock. If necessary, get extra locks from your supervisor.
• You must remove your own locks.
• You must not remove someone else's lock.
• If you apply the first lock, you must ensure that the machinery cannot be operated.
• In an emergency, a senior shift supervisor may remove someone else's lock, but only after every effort has been made to contact the person who put on the lock. The supervisor must ensure that the equipment will operate safely.

Identification requirement

The following items must be identified and acted on as part of a lockout procedure.

• Identify all energy sources that influence or are connected to the machinery or equipment.
• Identify the correct electrical source and disconnect it in the following way:
• For plugged-in equipment, pull the plug from the socket and place the male end on the equipment where it is readily visible.
• Identify the correct breaker and switch it to the off position.
• Identify the equipment to be shut down.
• Identify the correct switch and turn it to the off position. Use the following method and precautions.

Situations where lockout is required

Depending on the type of machine involved, in addition to electrical power, you must consider the following sources of energy:

• hydraulic fluids under pressure
• compressed air or gases
• energy stored in springs
• potential energy from suspended parts
• electrical components that hold a charge
• any other source that might cause mechanical movement

Lock-out equipment

There are many different types of locking systems.

Chains and or cables

If you need to lock out equipment with more than one energy source, instead of using several locks you could use a lockout cable to lock out several disconnect switches. This cable would be run through the locking hole in each of the safety disconnects you are locking out. The cable diameter must be large enough prevent the safety disconnect switches from being operated accidentally. A scissor lock adapter can be used to apply multiple locks.

Tags, locks and scissors

Lockout devices must provide a visual verification, must be locked as required and have a "DO NOT OPERATE" tag placed on them.

The tag must have on it your name, the date and time, and the location and identity of the equipment being worked on.

Only when the last worker removes his/her tag will the machine be safe to operate.

Lockout for circuit breakers

Lock out the desired breaker. If there is access to the main breaker or disconnect that kills all power to the panel, and if no other workers need to lock out in that panel, then you may lock the panel door closed.

Cord locks

For plugged-in equipment, if the male end of the plug is in view and you do not leave the machine until you have finished working, a lock is not needed. If the plug is not in view, use an adapter and lock, or lock the cord to an object to prevent it from being reconnected to the circuit. Figure 6 shows a power cord plug lock.

Lockout boards

A lockout station has keyed locks to be used only for equipment lockout. It also contains tags and lockout devices. Locks have one key that is kept with the installer of the lock. Once the work procedure is completed, the lock and key should be returned to the lockout station. These stations can be portable or mounted permanently to the wall where required.

Key box system

Machines are often powered by several sources, so situations can arise where a single job requires you to lock out more than one power source. This can be done efficiently and safely with a key box system.

A key box is a box mounted on a wall, containing two sets of locks. Lock Set A is mastered to a single key and Lock Set B is mastered to a different single key. The key box is treated as a locked out power source. All the regulations of a lockout apply to the key box. A key box lockout procedure checklist must be posted at the key box. Also other workers may add their locks to the key box.