What counts as a confined space?
A confined space is a place that is largely enclosed, where someone could be seriously hurt by a lack of oxygen, toxic gas or fumes, fire, flooding or free-flowing solids. Tanks, silos, pits, sewers and a ship's tanks are common examples. The Confined Spaces Regulations 1997 say you should avoid entry where you can, and follow a safe system of work when you can't.
This is a template, so adapt it to your own procedure, equipment and risk assessment, and have a competent person approve it, before anyone uses it.
When: before anyone enters a confined space such as a tank, vessel, silo, pit, chamber or enclosed duct, where there is a risk from gas, fumes, lack of oxygen, flooding or engulfment.
Before you start
First ask whether the work can be done from outside. If entry is needed, it needs a risk assessment, a safe system of work and, normally, a permit to work issued by an authorised person.
Steps
- Issue the permit. The authorised person names the space, the work, the entrants, the attendant and the time limits.
- Isolate the space. Lock off mechanical and electrical equipment, and blank or disconnect pipework rather than relying on closed valves.
- Clean, purge and ventilate the space as the permit sets out.
- Test the atmosphere from outside with a calibrated gas detector, for oxygen, flammable gas and any toxic gases named in the risk assessment. Test at the top, middle and bottom.
- Record the readings on the permit. Do not enter if any reading is outside the limits the permit sets.
- Check the rescue arrangements are in place before anyone goes in: the rescue team, the equipment at the entrance (such as a tripod, winch and harness) and a way to raise the alarm.
- Brief everyone. Entrants and attendant agree the hazards, how they will communicate and the signal to get out.
- Enter. Entrants wear the equipment the permit lists, including a personal gas monitor. The attendant stays at the entrance throughout and logs everyone in and out.
- Keep monitoring. Everyone leaves at once if an alarm sounds, ventilation fails or conditions change.
- Close the permit. When the work is complete, everyone leaves, the attendant confirms the count and the permit is handed back and closed.
Never go in to help someone who has collapsed unless you are part of the trained rescue team with the right breathing apparatus. Would-be rescuers are often among those killed in confined space incidents.
Toolbox talk
- Which spaces on this site count as confined spaces?
- Who is the authorised person today?
- What is the signal to get out, and what does the attendant do next?
Further reading: the Confined Spaces Regulations 1997 and HSE L101, Safe work in confined spaces.
These templates are general outlines for UK workplaces, provided free and without warranty. They do not replace your own risk assessment, training, supervision, permit systems or manufacturers' instructions. You are responsible for checking and approving any guide before it is used.