Occupational health & safety
Lockout/Tagout (LOTO)
Definition
Lockout/tagout is a set of practices for controlling hazardous energy during the servicing and maintenance of machines and equipment: energy-isolating devices are locked in the off position (lockout) and tagged to warn against re-energisation (tagout), with stored energy released or restrained before work begins. In the US it is codified in OSHA standard 29 CFR 1910.147.
References
regulatory definition and programme requirements
procedure steps, hazardous energy types
This reference provides supporting context for how “Lockout/Tagout (LOTO)” is defined and used.
Overview
What it means
Machines can be energised by electricity, hydraulics, pneumatics, steam, gravity or tensioned springs. LOTO ensures every energy source is identified, isolated and physically secured, with only the worker who applied a lock able to remove it.
How it is used
Written LOTO programmes, energy control procedures, employee training and periodic inspections are legally required in many jurisdictions before maintenance, cleaning or unjamming of equipment.
Why it matters
Failure to control hazardous energy is a leading cause of serious workplace injuries and fatalities — amputations, electrocutions and crushing — most of which are preventable through LOTO.