Permit to Work System

A permit-to-work system is a formal, documented authorisation for hazardous work — a defined scope, a defined duration, a defined set of controls, and a named issuer and acceptor. The permit types cover the work that produces the serious injuries: hot work, confined-space entry, working at height, electrical isolation, excavation, and radiography. The permit is issued by an authorised person, accepted by the work-team lead, and formally closed on completion with the controls released and the area returned to service.

The closure is where most PTW systems fail. A permit that is opened and never closed leaves the isolation in place after the work is done, which produces the next incident — the line re-energised while someone is still in it, the confined space re-entered without a fresh gas test. A defensible PTW system makes closure a hard step, ties the permit to the lockout-tagout record, and refuses to release the isolation until the closure is signed. PTW failures are implicated in most major industrial disasters for a reason: the work was authorised, the controls were listed, and no one verified they held. See LOTO, hot work, and confined space.