SiteIt's half past four on a Sunday morning. The steam supply to the cooker has a leaking flange. The day shift raised a permit for it on Saturday, isolated the line and got halfway through before they ran out of time.
Now the night shift wants to finish it. The permit is in the shift manager's drawer. Nobody on nights issued it. Nobody's sure whether the isolation is still in. And the only person who can sign a new one is asleep at home.
So the job sits. Or worse, someone finishes it on the old permit and hopes.
Most sites have a permit system. Few have one that works at 4am. Where it breaks is the handover, the hand-back and having someone on shift who can sign.
A permit doesn't make the job safe
HSE's guide on permits says it straight. A permit "is not simply permission to carry out a dangerous job". The issue of a permit "does not, by itself, make a job safe". The people who prepare, supervise and do the work make it safe (HSG250, paragraph 5).
So treat the permit as the record of a plan. It shows who checked what, what's isolated, and what the work is. HSG250 calls it a formal recorded process and "a means of communication" between management, supervisors, operators and the people doing the work (HSG250, paragraph 9).
HSG250 was written for the petroleum and chemical industries. Its principles fit any site with hazardous maintenance.
When you need one
Not for everything. HSG250 warns that putting permits on all activities weakens them. They aren't normally needed for routine maintenance in non-hazardous areas (HSG250, paragraph 14).
They fit best on non-production work, non-routine jobs, jobs where two or more groups need to co-ordinate, and jobs handed from one group to another (HSG250, paragraph 15). HSE's maintenance page adds that permits "are required in some cases" for high-risk maintenance (HSE, maintenance of work equipment).
On a factory or warehouse site, that usually means:
- hot work: welding, cutting and grinding
- breaking into a line carrying steam, ammonia, chemicals or high-pressure air
- entry into tanks, silos, pits and other confined spaces
- electrical work that could give rise to danger
- work at height off a MEWP or on a roof
All of those appear in HSG250's list of jobs that may need a permit or certificate (HSG250, paragraph 17). We cover two of them in more depth in hot work permits and confined spaces.
The electrical permit is different
An electrical permit is a statement that the kit is safe to work on, isolated and earthed where needed. HSG85 says you must never issue one for live work (HSG85, paragraph 69). The issuer should be authorised in writing by the employer (HSG85, paragraph 73). If the issuer will also do the work, HSG85 strongly recommends someone else makes an independent check of the precautions (HSG85, paragraph 80).
That last one matters on a small site with one sparky on nights. If there's no second person to check, you've found a gap. Our guide to safe isolation covers the steps that go on the permit.
Display it where the work is
A copy should be on show at the work site, or near it, and in the control room (HSG250, paragraph 18). HSG250 records that during the Piper Alpha inquiry, permits were often kept in the pocket of the person doing the job instead of on display (HSG250, case study 10). If a permit's in a drawer, nobody can see what's isolated.
Suspended still means live
Work gets stopped. Spares don't turn up. The scope changes. HSG250 is clear: "a suspended permit remains live until it is cancelled" and there may still be active isolations under it (HSG250, paragraph 19). Nobody should restart until the issuer has checked it's safe and revalidated the permit or issued a new one (HSG250, paragraph 20).
Back to the cooker. The day shift's permit is suspended, not dead. The isolation should still be in. But somebody with authority has to go and check before nights pick up a spanner.
Handover is where it breaks
When a job runs over a shift, the incoming shift needs to know which permit jobs are open, where each job has got to, and the state of the plant. HSG250 recommends the incoming issuer signs to allow the permit to carry on (HSG250, paragraph 23).
This is the cost of not having the right person on shift. If only days can issue permits, every job that runs past six becomes a stopped job. The callout engineer waits at the gate. The line waits behind them. You pay for both. Have someone authorised to issue on every shift, or plan permit jobs so they finish inside one. Our post on shift handovers covers the rest of what needs to pass between shifts.
Hand-back closes the loop
HSG250 describes a case where two fitters were working on steam pipes under one permit. One thought the job was done and handed the permit back. The operator opened the steam valve. The other fitter was still on the open pipe and was scalded. The system had no signing-off procedure (HSG250, case study 5).
So the hand-back should answer three questions (HSG250, paragraph 24). Is the work finished, confirmed by the person the permit was issued to? Is the plant back in a safe state, with isolations removed and checked? Has the person in charge of production signed to take it back?
For electrical permits, whoever received the permit signs to say earths and tools are removed and the team is withdrawn. They also say whether the kit is fit for service (HSG85, paragraph 82).
Our view
In our experience, permit systems fail on people. Who can issue, who's on shift, and whether the handover happens face to face. Get those three right and a one-page form will do. Get them wrong and a ten-page form won't help.
What to do on Monday
- List who is authorised to issue permits, by name and shift. Mark every shift with nobody.
- Check where live and suspended permits are kept. Move them to a board at the job or in the control room.
- Add a permit line to your shift handover sheet: open permits, suspended permits, isolations still in.
- Read your hand-back section. If it doesn't need every person on the permit to sign off, change it.
* HSE guidance correct as of 9 September 2026. Check HSG250 on HSE's website and HSG85 for the latest. HSG250 references are to the first edition (2005). HSG85 references are to the third edition (2013).