Lockout/Tagout (LOTO) refers to the practices and procedures outlined in OSHA standard 29 CFR 1910.147, "The Control of Hazardous Energy." These procedures protect workers by ensuring that machines and equipment are properly shut down, isolated from all energy sources, and secured before maintenance or servicing. Energy sources include electrical, mechanical, hydraulic, pneumatic, chemical, thermal, and gravitational. Employers must develop machine-specific written procedures, provide locks and tags, train all affected employees (authorized, affected, and other), and conduct annual inspections of each procedure. LOTO is consistently among OSHA's top 10 most-cited violations.