The Confined Spaces Regulations 1997 apply wherever people enter tanks, vessels, pits, chambers and other enclosed places where the air or conditions can quickly become dangerous. This guide explains in plain terms what counts as a confined space, the three core duties, what the safe system of work should cover and how the rules link to the other regulations warehouses and workshops already follow.
What are the Confined Spaces Regulations 1997?
The Confined Spaces Regulations 1997 (SI 1997/1713) were made under the Health and Safety at Work etc. Act 1974. They apply to employers, the self-employed and anyone who controls work in a confined space in Great Britain. HSE publishes the Approved Code of Practice and guidance as Safe work in confined spaces (L101), which explains how to meet them. Following the Approved Code of Practice is the usual way to show compliance.
What counts as a confined space?
The definition has two parts, and both need to apply:
- The place is substantially, though not always entirely, enclosed.
- There is a reasonably foreseeable risk of serious injury from hazardous substances or conditions within the space or nearby.
Typical examples include storage tanks, silos, vats, reaction vessels, sewers and manholes, ductwork, pits and chambers. A space can be confined even if it is not small. An open-topped tank can qualify, while a small cupboard with no foreseeable risk does not.
The specified risks
The regulations name the hazards that make an enclosed space a confined space:
- Fire or explosion.
- Loss of consciousness from an increase in body temperature.
- Loss of consciousness or asphyxiation from gas, fumes, vapour or a lack of oxygen.
- Drowning from an increase in the level of a liquid.
- Asphyxiation from a free-flowing solid, or being unable to reach a breathable atmosphere because of being trapped by one.
The three core duties
- Avoid entry. No one should enter a confined space to carry out work if it is reasonably practicable to do the job another way, for example by cleaning, inspecting or sampling from outside.
- Follow a safe system of work. If entry cannot be avoided, the work must be planned and carried out under a safe system of work that controls the risks.
- Have emergency arrangements. Suitable rescue and emergency arrangements must be in place before work starts, and they should not rely on the public emergency services alone.
What a safe system of work should cover
The Approved Code of Practice expects a risk assessment first, then precautions that fit the space and the task. These normally include:
- Isolating the space from connected pipes, supplies and moving parts.
- Testing and, where needed, monitoring the atmosphere, and ventilating the space.
- Controlling flammable and toxic substances, and keeping ignition sources out.
- Competent, trained and medically suitable people, with communication and a person outside who can raise the alarm.
- Suitable equipment and PPE, including respiratory protection where the assessment calls for it. See our PPE at Work Regulations guide.
- A permit to work for higher-risk entries. The regulations do not name one, but it is a common way of making sure precautions are in place before entry.
Emergency arrangements and rescue
Rescue must be planned before anyone goes in. That means trained rescuers, the right equipment, a way to raise the alarm without the rescuer entering unprotected, and arrangements that suit the specific space. Many fatalities in confined spaces involve would-be rescuers, which is why the plan matters as much as the entry procedure.
How the regulations link to COSHH, DSEAR and other duties
- Hazardous substances in or near the space are covered by COSHH.
- Flammable gases, vapours and dusts are covered by DSEAR.
- The general duty to assess risk comes from the Management of Health and Safety at Work Regulations 1999.
- Entry at height, such as a ladder into a pit or tank, brings in the Work at Height Regulations 2005.
- Serious incidents may be reportable. See our RIDDOR guide.
Storage and containment around tanks and vessels
Many confined-space incidents start with what is stored in or near the space. Keeping hazardous liquids in the right place reduces the number of spaces that become hazardous in the first place. Flammable and corrosive liquids belong in suitable hazardous storage. Drums and IBCs should stand on suitable IBC containment pallets or spill containment, and drums can be kept upright in vertical drum storage. These products do not make a space safe to enter, but good storage and containment help keep spills out of pits, sumps and low areas.
Confined Spaces Regulations FAQs
What are the Confined Spaces Regulations 1997?
Regulations made under the Health and Safety at Work etc. Act 1974 (SI 1997/1713). They set out duties for anyone who controls or carries out work in a confined space in Great Britain, supported by an HSE Approved Code of Practice and guidance, L101 Safe work in confined spaces.
What counts as a confined space?
A place that is substantially, though not always entirely, enclosed, and where there is a reasonably foreseeable risk of serious injury from hazardous substances or conditions within the space or nearby. Both parts of the definition must apply.
What are the specified risks?
Fire or explosion; loss of consciousness from an increase in body temperature; loss of consciousness or asphyxiation from gas, fumes, vapour or lack of oxygen; drowning from an increase in liquid level; and asphyxiation from a free-flowing solid, or being unable to reach a breathable atmosphere because of being trapped by one.
What are the three main duties?
Avoid entering a confined space if the work can reasonably be done another way; if entry cannot be avoided, follow a safe system of work; and put adequate emergency arrangements in place before work starts.
Is a permit to work a legal requirement?
The regulations do not name a permit to work, but the safe system of work for a higher-risk entry is commonly managed with one. HSE guidance says a permit is a way of making sure the precautions are in place, not a substitute for them.
Can we rely on the fire brigade for rescue?
No. Emergency arrangements need to be in place before entry and should not depend on the public emergency services alone. Rescue should be planned, resourced and, where appropriate, practised.
Are storage tanks and IBCs confined spaces?
They can be, if the definition is met, for example when someone enters a tank and a specified risk is reasonably foreseeable. Whether a particular tank, vessel or pit counts depends on a risk assessment of the space and the work.
Who has to comply?
Employers and the self-employed, and anyone with control of the premises or the work. Employees must also co-operate and follow the safe system of work.
Do the regulations connect to COSHH and DSEAR?
Yes. Hazardous substances and flammable atmospheres in a confined space also fall under COSHH and DSEAR, so the risk assessment should consider them together.