By Sphera’s Editorial Team | March 18, 2022

Work performed in industry and research settings can involve electrical, mechanical, hydraulic, pneumatic, chemical and thermal energy. While we have harnessed these energies for the greater good, they also present hazards, and it’s the employer’s responsibility to protect employees from harmful interactions with the energy sources they use. Lockout/tagout (LOTO) procedures were developed for this purpose.

To understand the vital role of LOTO procedures, it’s important to know what can happen when they’re not in place. In 2006, a Texas-based airplane mechanic was killed when he was sucked into the right engine of a plane as passengers boarded. After addressing an earlier engine problem, workers failed to take the steps that would have prevented the mechanic’s interaction with the energized engine. Unintended interactions with machinery and equipment still cause workplace accidents, but their frequency and severity have been greatly reduced by LOTO procedures.

The Meaning and Origins of Lockout/Tagout (LOTO)

Lockout involves an actual lock that prevents the release of energy from a machine or system. The lock keeps the machine or equipment from activating unexpectedly during service or maintenance. Tagout involves placing a tag on an on-off switch or other shut-off device to tell workers not to energize the machinery or equipment. The lockout and tagout processes are typically performed together, with the energy both locked out and tagged out at its source.

To understand the origins of LOTO, we must go back to the 1970s. Section 6(a) of the Occupational Safety and Health Act of 1970 authorized the U.S. secretary of labor to adopt national consensus standards. It also established federal standards issued under other statutes (for example, the Contract Work Hours and Safety Standards Act, also known as the Construction Safety Act) as occupational safety and health standards. In 1971, OSHA introduced 29 CFR part 1910 Occupational Safety and Health Standards to incorporate certain national consensus standards and established federal standards for general industry. These policies and pieces of legislation were prompted by workplace incidents that gravely illustrated the necessity of safety standards and LOTO procedures. In 1970 alone, the U.S. workforce of roughly 83 million witnessed an astounding 14,000 worker fatalities – an average of 38 deaths per day.

A series of amendments to 29 CFR part 1910 followed, but workplace injuries and fatalities continued. In 1979, the United Auto Workers (UAW) union petitioned OSHA for an Emergency Temporary Standard (ETS) following 22 auto worker fatalities that were attributed to lockout failure. While OSHA did not issue an ETS, it published an Advance Notice of Proposed Rulemaking (ANPR) for a lockout / tagout standard in 1980. OSHA’s Standard for Control of Hazardous Energy (Lockout/Tagout), 29 CFR 1910.147, followed in 1989, laying the policy foundation for the LOTO procedures in use today.

Why is LOTO important?

Workers are aware of the risks presented by the equipment they use, and systems and safeguards are in place to protect them during normal operations. But maintenance and repair activities can require the removal of these safeguards, so it is standard practice to terminate the flow of energy during maintenance or repair. LOTO provides robust procedures and tools to ensure that this standard practice is carried out as intended.

Environmental, health and safety publication EHS Daily Advisor reported on an incident involving a 17-year-old who worked a summer job managing a conveyor that dropped waste cardboard into a baler. In the incident, the conveyor belt jammed, and the teen climbed into the baler to dislodge the jam. The conveyor belt unexpectedly restarted, pulling him into the baler and causing the loss of both his legs. The accident could have been prevented by adherence to LOTO procedures.

Lockout/Tagout Steps

In the workplace, energy-reliant systems typically have energy-isolating devices that can shut down the energy source. OSHA defines an energy-isolating device as “A mechanical device that physically prevents the transmission or release of energy, including but not limited to the following: A manually operated electrical circuit breaker; a disconnect switch; a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors and, in addition, no pole can be operated independently; a line valve; a block; and any similar device used to block or isolate energy.”

For additional protection, a physical lockout device can be placed on the energy-isolating device and secured with a padlock. OSHA defines the lockout device as “Any device that uses positive means, such as a lock, blank flanges and bolted slip blinds, to hold an energy-isolating device in a safe position, thereby preventing the energizing of machinery or equipment.” Additional examples include multiple in-line ball valve and gate valve lockouts, circuit breaker lockouts, plug and wall switch lockouts and pneumatic lockouts.

The tagout component of LOTO requires a warning tag on the physical restraint device. The tag indicates who locked it out and when and why it was locked out. The tag stays in place for the duration of maintenance or repair activities.

Aside from the physical locking and tagging of equipment, LOTO requires other steps. Affected workers must be prepared for and notified of the upcoming lockout. Authorized personnel then shut down equipment and isolate energy sources, after which the locking and tagging take place. The next step – a critical and sometimes neglected one – is the release or control of any stored energy, such as compressed air or high-pressure fluids. Once this step has been completed safely, authorized personnel verify the lockout and only then can maintenance on the isolated equipment be performed.

LOTO release protocols must be followed once the maintenance or repair work has been completed. The authorized personnel remove the lockout devices and tags, inform other affected employees of their removal and then test the equipment. After these steps are completed, the equipment can then be re-energized for normal operations.

Training for LOTO

Energy-isolating devices and lockout/tagout devices are effective only when workers use them correctly, so training is essential for their proper use. Only authorized personnel can handle shut down and lockout/tagout of equipment. They must be trained on LOTO regulatory requirements and on the LOTO policies and standards set by the asset owner, including specific procedures for the equipment they are assigned to. Affected employees – workers whose job involves the equipment, but who are not authorized for lockout/tagout procedures – must also be instructed in why and how LOTO procedures are used. This instruction must also be provided to employees who work in an area where LOTO controls are used, even if they don’t rely on the equipment.

LOTO saves lives.

OSHA fines companies that do not sufficiently protect employees from preventable accidents, including those that should have been prevented by LOTO procedures. In fact, Lockout/Tagout citations ranked sixth among OSHA’s top 10 most frequently cited violations in FY 2021. Following a March 2021 fatality at an Ohio aluminum parts manufacturer, OSHA Chief Jim Frederick said, “OSHA will continue to hold bad actors accountable and emphasize the importance of complying with safety and health requirements that can save lives.” And LOTO procedures do indeed save lives: it is estimated that they prevent roughly 120 fatalities and 50,000 injuries each year in the USA alone.