Full definition
Any workplace hazard posed by moving parts of machinery or equipment that can cause injury through entrapment (caught-in, caught-between), cutting/severing, shearing, crushing, puncture, abrasion, or impact with projected objects. Mechanical hazards are among the most common causes of serious workplace injuries and amputations. Hazard sources: (1) Point of operation — where the machine performs work on material (press dies, saw blades, grinding wheels). (2) Power transmission — components transferring energy (belts, pulleys, gears, chains, sprockets, couplings, shafts). (3) Other moving parts — reciprocating, rotating, or transversing parts (conveyor belts, robot arms, mill rollers). Control hierarchy per NOM-004-STPS-1999 and OSHA 29 CFR 1910.212: (1) Guard all hazardous moving parts (fixed, interlocked, adjustable, or presence-sensing guards). (2) Safety devices (light curtains, safety mats, two-hand controls, emergency stops). (3) LOTO procedures for maintenance and repair. (4) Training on hazard awareness and safe work procedures. (5) Signage — warning labels on all points of hazard per NOM-026-STPS. Never operate machinery with guards removed or bypassed. In belt drive maintenance: LOTO before any work near pulleys, belts, or rotating shafts.