To define LOTO: Lockout/Tagout is the safety procedure that controls hazardous energy during service and maintenance of machines and equipment. For general contractors, LOTO compliance is not optional. OSHA consistently ranks lockout/tagout violations among the top 10 most-cited standards, with over 2,400 citations issued annually. The average penalty for a serious LOTO violation reached $16,131 in 2025, and repeat violations can exceed $160,000.

This pillar guide covers everything a GC needs to know about LOTO: the definition, OSHA standards, enforcement responsibilities on multi-employer worksites, and how to build a compliance tracking system that protects your projects.

What LOTO Means in Construction

LOTO stands for Lockout/Tagout. It refers to the specific practices and procedures that protect workers from the unexpected release of hazardous energy during service or maintenance activities.

Lockout involves placing a physical lock on an energy-isolating device (a circuit breaker, valve, or disconnect switch) so the device cannot be operated. Only the worker performing the service holds the key.

Tagout involves attaching a warning tag to an energy-isolating device. The tag states that the equipment cannot be operated and identifies the worker who placed it. Tags are used when lockout devices cannot physically be applied.

The hazardous energy sources covered by LOTO include electrical, mechanical, hydraulic, pneumatic, chemical, thermal, and gravitational energy. On construction sites, workers encounter these energy sources when servicing HVAC systems, temporary electrical panels, elevators, pumps, compressors, and heavy equipment.

OSHA's LOTO Standard: 29 CFR 1910.147

OSHA's Control of Hazardous Energy standard (29 CFR 1910.147) establishes the minimum LOTO requirements. While this standard falls under General Industry (1910), it applies to construction activities that involve servicing equipment.

Construction-specific OSHA standards also address hazardous energy control in 29 CFR 1926 Subpart K (Electrical) and Subpart CC (Cranes and Derricks). GCs must comply with both general industry and construction standards when their workers service equipment on site.

The key requirements under 1910.147 include:

Written procedures. Employers must develop documented LOTO procedures for each piece of equipment that has hazardous energy sources. Generic, one-size-fits-all procedures do not satisfy OSHA requirements.

Training. Three categories of workers need training: authorized employees (who perform LOTO), affected employees (who work near locked-out equipment), and other employees (who work in areas where LOTO is used). Each group requires different training content.

Periodic inspections. Employers must inspect their LOTO program at least annually. The inspection must be conducted by an authorized employee other than the one being observed. Results must be documented.

Hardware. Locks, tags, hasps, and other energy-isolating devices must be durable, standardized, substantial, and identifiable. Tags must include the name of the authorized employee and the date of application.

GC Responsibilities on Multi-Employer Worksites

Construction sites are multi-employer worksites. Multiple subcontractors may service equipment at different times, creating overlapping LOTO exposure. The GC's responsibilities include:

Coordination. When two or more employers perform LOTO on the same equipment, the GC must coordinate procedures. Each employer must inform the others about their lockout/tagout devices and the sequence for applying and removing them.

Verification. The GC should verify that each subcontractor has written LOTO procedures for the equipment they service. Ask for copies during subcontractor qualification.

Group lockout. When multiple workers from different employers service the same equipment, group lockout procedures must be in place. A primary authorized employee coordinates the group lockout, and each worker applies their own personal lock.

Communication. The GC must establish a communication system that alerts all workers when equipment is locked out and when LOTO devices are removed. On large projects, this often involves a central lockout log maintained by the site superintendent.

Types of Hazardous Energy on Construction Sites

Understanding the energy sources on your projects helps you identify where LOTO applies.

Energy Type	Common Sources on Construction Sites	Risk Level
Electrical	Temporary panels, transformers, switchgear, generators	High (electrocution, arc flash)
Mechanical	Conveyors, elevators, hoists, rotating equipment	High (crushing, amputation)
Hydraulic	Excavators, lifts, hydraulic presses, pipe systems	Medium-High (crush injuries)
Pneumatic	Compressors, nail guns, pneumatic tools, air lines	Medium (projectile, burst)
Thermal	Boilers, steam lines, welding equipment, HVAC	Medium (burns)
Chemical	Piping systems, storage tanks, process equipment	Medium-High (exposure, reaction)
Gravitational	Suspended loads, elevated platforms, counterweights	High (falling objects, collapse)

Building a LOTO Compliance Program

GCs that build structured LOTO programs reduce their TRIR and protect their experience modification rate. Here is the framework.

Step 1: Inventory hazardous energy sources. Walk each project during preconstruction and identify every piece of equipment that has stored or active energy. Document the energy type, isolation points, and required LOTO devices.

Step 2: Develop equipment-specific procedures. Write a procedure for each machine or system. The procedure must identify the energy sources, isolation devices, lockout method, and steps for verifying zero energy state.

Step 3: Procure standardized hardware. Issue locks, tags, hasps, and lockout devices that meet OSHA requirements. Color-code locks by employer or trade to simplify identification on multi-employer sites.

Step 4: Train all workers. Authorized employees need detailed procedural training. Affected employees need awareness training about LOTO protocols on the site. Retrain after any incident or procedure change.

Step 5: Conduct annual inspections. Assign an authorized employee to audit the program annually. Document the inspection, including which procedures were reviewed, which workers were observed, and what corrections were made.

Step 6: Track compliance digitally. Use a compliance platform to store procedures, training records, inspection reports, and sub certifications. Automated alerts ensure nothing lapses.

LOTO and Subcontractor Management

Subcontractors performing electrical, mechanical, and plumbing work are the most common trades that encounter LOTO situations on construction sites. GCs should require the following from every sub that performs service or maintenance work:

Written LOTO procedures specific to the equipment on your project. Training records for all authorized and affected employees. Evidence of annual LOTO program inspections. Lock and tag inventory showing standardized, employer-identified hardware.

Read our detailed guides on each aspect of LOTO compliance:

FAQs

What does LOTO stand for in construction? LOTO stands for Lockout/Tagout. It is the safety procedure for controlling hazardous energy during service and maintenance of equipment. Lockout uses physical locks to prevent equipment operation. Tagout uses warning tags to alert workers that equipment is being serviced.

Is LOTO required on construction sites? Yes. OSHA's Control of Hazardous Energy standard (29 CFR 1910.147) applies to construction activities that involve servicing equipment with hazardous energy sources. Additional construction-specific requirements exist in 29 CFR 1926 for electrical work and crane operations.

Who is responsible for LOTO on a multi-employer construction site? The GC is responsible for coordinating LOTO procedures across all employers on the site. Each subcontractor must have their own written LOTO procedures and trained authorized employees. The GC must verify that subs comply and coordinate group lockout when multiple employers service the same equipment.

What types of energy does LOTO cover? LOTO covers all forms of hazardous energy: electrical, mechanical, hydraulic, pneumatic, chemical, thermal, and gravitational. On construction sites, the most common exposures involve electrical panels, rotating equipment, hydraulic systems, and pressurized lines.

What is the penalty for LOTO violations? The average OSHA penalty for a serious LOTO violation is $16,131. Willful violations can reach $161,323 per violation. Repeat violations carry penalties up to $161,323. LOTO consistently ranks in OSHA's top 10 most-cited standards, meaning inspectors actively look for violations.

How often must a LOTO program be inspected? OSHA requires at least one annual inspection of the LOTO program. The inspection must be performed by an authorized employee who was not the one being observed. The inspection must review equipment-specific procedures and verify that employees understand and follow them.

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