Lockout/tagout is used to protect workers from the unexpected re-energization of equipment. Hazardous energy sources are isolated during servicing in order to help prevent injury. For this purpose, special equipment is used, such as a safety padlocks, lockout boxes, lockout boards and others. However, it is sometimes difficult to determine when a machine must be locked out and when servicing can be safely accomplished without lockout.
When to Lockout a Machine
According to OSHA’s Control of Hazardous Energy regulation, a machine must be locked out any time one of the following conditions occur:
- An employee must remove machine guarding.
- An employee bypasses a guard, interlock, or other safety device.
- An employee places part of their body in harm’s way.
- An employee performs any major servicing or maintenance work.
What is Considered Servicing?
OSHA classifies many tasks as servicing activities, including the following:
- Constructing or installing a new machine.
- Setting up a machine to perform normal operation.
- Renovating or modifying an existing unit.
Repairing a machine.
- Making machine adjustments or major tool changes.
- Inspecting a machine for errors, jams, or other problems.
- Cleaning inside the unit.
- Clearing a jam or debris.
- Lubricating parts inside the machine.
- Any other maintenance or servicing tasks where the employee may be exposed to release of hazardous energy.
When Lockout May Not be Needed
Work done during normal operation that is a part of the machine’s intended use is exempt from lockout/tagout. Servicing work done during normal operation is not exempt unless it falls under one of the following situations.
Cord and plug equipment, where electrical energy is the only hazardous source and can be under the exclusive control of the employee is exempt. The electrical disconnect must be a plug located near enough to the equipment that it cannot be energized without the authorized employees knowledge.
Hot Tap Work
Hot tap operations may be exempt for lockout/tagout provided the employer can show that:
- Continuity of the system is essential to plant operations;
- Shutdown of the system is impractical, and; Other safety measures are used to provide additional protection to the employee(s).
Minor Servicing Activities
Minor servicing activities such as minor tool changes and adjustments, that take place during normal operating conditions, can be done without locking out the machine so long as:
- The work is routine;
- The task is repetitive, and;
- The task is integral to the use and operation of the equipment.
Alternative safety measures should be taken to provide employees additional protection.