 Examples of high-risk jobs where a written permit to work procedure may need to be used include hot work such as welding, vessel entry, cutting into pipes carrying hazardous substances, diving in the vicinity of intake openings, and work that requires electrical or mechanical isolation.It is also a means of coordinating different work activities to avoid conflicts.A permit to work is not a replacement for robust risk assessment, but can help provide context for the risk of work to be done.