I was recently asked to provide a training module on lockout/tagout to a group of maintenance mechanics and machine operators at a precision machine shop. They had recently had an incident where a maintenance person was injured during a routine maintenance operation. Fortunately, the injury was not serious, and the worker did not have to seek medical treatment. However, like most workplace accidents, this incident could have been prevented with a compliant lockout/tagout program.
An OSHA regulation states that lockout/tagout (LOTO) operations can only be performed by persons trained in the specific operations of the affected equipment. And locks or tags cannot be removed by anyone other than properly trained personnel.
When LOTO Goes Wrong
As it happened, the operator took lunch while the mechanic locked out his machine to replace a leaking hydraulic fitting. The machine had been de-energized and was tagged or locked out. While waiting for a fitting and hose, the mechanic went on to other tasks. The operator, returning from his lunch break saw that the machine access cabinets were closed again, and the main power switch was off. He did not notice the open end of the hydraulic line on the top of the seven-foot-high machine. Throwing the switch to the on position activated the hydraulic pump and forced oil into his face and eyes at a fairly high volume and pressure. He was able to make it to the nearby eyewash station and flood his eyes with clear water which may have saved his eyesight.
The root cause investigation of this incident revealed:
- Maintenance did not lock, but only tagged the main power switch, not in accordance with the written procedure
- Maintenance did not lock the hydraulic control valve in the off position
- The operator did not notice or read the tag and did not have knowledge of the purpose of the tag on the power switch (English is not his primary language)
- Neither workers had received on the job or classroom training in LOTO
- The LOTO procedures had not been audited in the last 12 months
Again, no trip to the hospital and no permanent injury. However, this could have been a very serious and costly situation. And a comprehensive lockout/tagout program could have prevented the incident.
Build an OSHA-Compliant Lockout/Tagout Program
As my training states: The purpose of the lockout/tagout program is “To protect workers involved in the maintenance and servicing of equipment from the dangerous effects of hazardous energy. This is achieved by isolating and locking or tagging out all hazardous energy sources.” – OSHA, Control of Hazardous Energy Lockout/Tagout
Six Critical Steps
There are six important steps in creating a compliant lockout/tagout program:
- Prepare! Brief the authorized employees on the type and magnitude of the energy, the hazards involved, and means to control the energy at the source.
- Shut Down the equipment in an orderly and safe manner according to the pre-planning process in the written procedure.
- Use LOTO Devices. Operate all Lockout-Tagout (LOTO) devices (valves or switches) to de-energize the equipment.
- Attach all LOTO Devices to the energy isolating devices (and, if appropriate, personal LOTO devices to group LOTO mechanisms when multiple workers are involved).
- Release all stored energy such as electric charge, pressure, charged springs, etc. Remember springs, capacitors, gravitational, and other sources of energy may need to be controlled!
- Verify that equipment energy isolation has been accomplished.
Verification of a de-energized condition is often overlooked, causing accidents, equipment damage, injuries, and fatalities.