Posted By Coshh Assessor I'll own up to never having heard of such a thing. Anyone else?

Posted By Bob Youel they can and are used where the permit to work not only talks about the base systems of work but also considers things like radiation doses where access to an area is limited because of the dose conditions not just by the actual work being done and its interfaces restrictions can be included in many situations e.g. the permit to work is for 8 hours but the work part of that permit is for 6 of those 8 hours e.g. the actual hot works and the other 2 hours is for fire watch after the hot work has finished