By Craig Collier, Director, StructAssure
A permit to work is often treated as a form to be signed before a job can start. It is not.
A permit is the written record of a decision that a high-risk task has been made as safe as it reasonably can be, that the right precautions are in place, and that everyone involved knows what those precautions are and who is accountable for them.
When an incident happens on a hot works, confined space or excavation task, the permit is one of the first documents an HSE inspector or an insurer asks to see, because it shows whether the work was controlled or merely authorised. The two are not the same, and the difference is usually visible in the detail on the page.
What a permit actually controls
The Health and Safety Executive sets out the principles in HSG250, Guidance on permit-to-work systems. A permit is appropriate where the risk is high enough that ordinary method statements and supervision are not a sufficient control on their own, and where the work needs to be positively coordinated, isolated and time-limited.
A permit that earns its place does five things:
- It names the specific task and location, not a general activity.
- It confirms the isolations and precautions that must be in place before work starts, and that they have been checked by someone competent.
- It sets a time limit, so that a permit cannot quietly remain live after the conditions it was issued under have changed.
- It cross-references the risk assessment and method statement that the precautions come from, rather than restating them loosely.
- It provides for a formal hand-back, so the person who issued it confirms the area is safe and the permit is closed. A permit with no hand-back is a permit that never actually ended.
The most common failing is the permit that is filled in once and then detached from reality. The work takes longer than planned, a second crew joins, the isolation is briefly broken to test something, and none of it reaches the permit. By the time anyone looks, the document describes a job that no longer exists.
A good system treats the permit as live: if the conditions change, the permit is suspended or re-issued, not quietly overrun.
Hot works permit
Hot works, meaning any task that produces heat, sparks or a flame, such as welding, grinding, cutting or the use of a blowtorch, are a leading cause of avoidable fires on site and in occupied buildings.
The permit has to do more than record that hot works are taking place. Under the Dangerous Substances and Explosive Atmospheres Regulations 2002, a permit should confirm that:
✔ Combustible materials have been removed or protected within a sensible radius
✔ Suitable fire extinguishers are to hand
✔ The area has been checked for flammable atmospheres where that is a possibility
The single control most often missed is the fire watch after the work stops. Smouldering material can take time to develop into a fire, so good practice is to keep a fire watch during the work and for at least sixty minutes after it finishes, with a further check an hour or two later before the area is left unattended. A permit that ends at the moment the torch is switched off has closed too early.
In England and Wales the fire precautions for work in occupied premises also sit within the Regulatory Reform (Fire Safety) Order 2005, which the permit regime should reflect rather than duplicate.
Confined spaces
A confined space is defined by its character, not its size: a place that is substantially enclosed where there is a reasonably foreseeable risk of serious injury from hazardous substances or conditions, such as a lack of oxygen, toxic gas, or free-flowing solids. Tanks, sewers, ducts, manholes and unventilated voids all qualify.
The Confined Spaces Regulations 1997, with the Approved Code of Practice L101, set the order of control clearly, and it is an order a permit should follow. The first duty is to avoid entry altogether where the work can reasonably be done another way, for example by cleaning or inspecting from outside.
Where entry cannot be avoided, a safe system of work is required, and the permit records it:
- The atmospheric testing before and during entry
- The ventilation
- The control of the task
- Communications with the person outside
- The limits beyond which everyone withdraws
The duty that is most often underdone is the one the regulations treat as essential, which is suitable and sufficient emergency arrangements before the work begins. Rescue cannot be improvised. If the plan for recovering an unconscious person from the space is not written, rehearsed and resourced before anyone goes in, the system is not ready, whatever the permit says.
Excavations
Excavations fail quietly and then suddenly. A face that has stood for a week is not evidence that it is safe, because the ground changes with weather, vibration and time.
The Construction (Design and Management) Regulations 2015 require:
✔ An excavation which could collapse is prevented from doing so by suitable support or by battering back to a safe angle
✔ Materials and loads are kept back from the edge
✔ Steps are taken to prevent people and vehicles falling in
They also require that the excavation is inspected by a competent person at the start of every shift before work begins, and again after any event likely to have affected its stability, such as heavy rain or an unexpected collapse, with the findings recorded.
A permit for excavation work should tie all of that together, and it should not be issued until the underground services have been located and proven. Striking a buried cable or a gas or water main is one of the most common serious excavation incidents, and it is almost always a failure of the checks that should have happened before the first bucket went in: drawings obtained, a cable avoidance tool used, and trial holes dug by hand where the risk is high.
Practical ways to measure whether the system actually works
A permit system can look complete and still fail, so it is worth asking how you would know it is working before an incident tells you it was not. The honest measures are leading ones, taken from the permits themselves.
- Sample live and closed permits and ask a plain question of each: could someone who was not there tell, from the permit alone, what the task was, what the precautions were, who checked them and whether the permit was properly closed.
- Track the proportion of permits that are formally handed back rather than left open or overrun, because open permits are the clearest sign that the system is being treated as paperwork.
- Watch whether permits are being raised for the right tasks and not for trivial ones, because a system that cries wolf trains people to sign without reading.
- Treat a near miss on a permitted task, a fire watch cut short, an atmosphere not tested, a service not located, as a reportable weakness in the system rather than a one-off, because it is telling you where the next incident will come from. Counting lost-time injuries tells you what already went wrong. Reading your own permits tells you what is about to.
What good looks like
A permit to work system that stands up to scrutiny is specific, live and honest. Each permit describes one real task, confirms the precautions have been checked by a competent person, sets a time limit, cross-refers to the assessment it came from, and is formally closed.
Hot works carry a fire watch that outlasts the work. Confined space entry is avoided where it can be, and never begins without rescue arrangements that are ready rather than assumed. Excavations are supported, inspected before each shift, and never opened until the services are proven.
None of this is onerous once the system is built to do the job rather than to produce a file. The test, as with so much in safety, is simple: hand a permit to someone who has never seen the site and ask whether they could tell that the work was controlled. If they cannot, the form has been completed and the task has not been made safe.
This is general guidance based on the regulations and HSE guidance current at the time of writing in October 2026. It is not a substitute for the regulations themselves, the relevant Approved Codes of Practice or professional advice, and it is written with Great Britain in mind; other jurisdictions differ.
About the author: Craig Collier
Craig Collier is Director of StructAssure. He’s a chartered construction and quality professional (MCIOB, CQP MCQI, MAPM) with more than twenty years on major UK programmes including Crossrail, the Woodsmith Mine and Transport for Wales. He writes about the practical side of health, safety and quality assurance in construction, and how the records that prove a job was done safely can be made to do real work rather than sit in a file.
References
- Health and Safety Executive (2005). Guidance on permit-to-work systems: A guide for the petroleum, chemical and allied industries. Available at: https://www.hse.gov.uk/pubns/books/hsg250.htm
- Health and Safety Executive (2022). Fire safety in construction. Available at: https://www.hse.gov.uk/pubns/books/hsg168.htm
- Health and Safety Executive (2014). Confined Spaces Regulations 1997. Approved Code of Practice, Regulations and Guidance L101. Available at: https://www.hse.gov.uk/pubns/books/l101.htm
