Work permit

A work permit, internationally a permit to work or PTW, is written authorisation to carry out a specific high-risk task at a specific place and time. The permit records which hazards have been identified, which measures have been taken, who may carry the work out and who releases it. Common variants are the hot work permit, the confined space permit and the excavation permit.

The system exists because most severe incidents in industry happen during maintenance rather than during normal production. The permit forces somebody to think before work starts, and forces a second person to test that judgement.

Where it goes wrong is rarely the form and almost always the routine. During a turnaround, hundreds of permits get issued in a week, and the question quietly shifts from what could go wrong here to who signs this off. Training that tackles this does not rehearse filling in the form; it rehearses recognising the moment when the situation on the floor differs from what is on the paper.