Countless workers have been seriously injured or killed because they did not ensure that all forms of hazardous energy were dissipated and locked and tagged out before conducting maintenance, repairs, servicing or new installations on equipment. This article explains what lockout/tagout is and six things supervisors need to know regarding their duties surrounding hazardous energy control.

Thousands of workers have been seriously injured or killed because they did not ensure that hazardous energy sources associated with machinery were locked out and tagged out before undertaking maintenance, repairs, servicing or new installations— only to have another unsuspecting worker come along and activate that machinery.

Many forms of hazardous energy can be found in workplaces. These include:

• electrical energy,
• chemical energy (created when a chemical reaction occurs),
• mechanical (or kinetic) energy, such as that contained within a compressed spring,
• hydraulic potential energy (stored within pressurized liquid),
• pneumatic potential energy (stored within pressurized air),
• gravitational potential energy,
• thermal energy (such as heated water, steam or radiation).

Major causes of injury or death related to machinery maintenance and repair or attempts to unblock jammed material, include:

• Failure to stop equipment before such work begins,
• Failure to disconnect machinery from power sources,
• Failure to dissipate all forms of energy,
• Accidental re-activation of equipment by other workers.

Workplace safety laws across North America require employers to protect workers performing maintenance or repairs by having authorized workers physically lock out and tag out all sources of hazardous energy before that work begins. Tagout involves attaching a label to the system containing an explanation of why the lock is in place, when it was applied and by whom.

The only worker permitted to remove a lock and tag is the authorized individual who placed them there.

Here are six things you need to know about your duties regarding hazardous energy control procedures:

1. You must develop, implement and enforce an energy control program if your workers potentially face exposure to hazardous energy. In addition to an energy control program, the US Occupational Safety and Health Administration (OSHA) requires that machine-specific energy control procedures be developed for each piece of equipment or machinery that may need to be locked out.
2. You must provide your employees with training on hazardous energy control procedures. That training includes informing your workers of the aspects of your workplace’s hazardous energy control program; how it applies to their particular job duties; and the lockout/tagout safety requirements for your jurisdiction (federal or state OSHA program or provincial OHS program). Some machinery and equipment is incapable of being locked out, although with such a wide variety of lockout devices available today, there are very few situations where something cannot be locked out. In cases where lockout is not possible, tagout devices may be used instead of lockout devices, but only if they provide the same level of protection to workers. Although cord and plug equipment does not need to be locked out, workers must ensure they are in control of the plugs at all times when performing repairs or servicing.
3. Ensure that only the appropriate lockout/tagout devices authorized for particular equipment are used and that they are substantial and durable.
4. Ensure that each tag identifies the authorized person performing lockout/tagout.
5. Ensure that all workers know that only authorized persons are to remove locks and tags.
6. Inspect your hazardous energy control program at least once per year and ensure it is up to date. Certain jurisdictions, including those covered by OSHA, require that specific energy control procedures be audited.