Every year people die in tanks, pits, sewers and voids, and a large share of them are the colleagues who go in to help. Confined space training exists to stop both. This guide explains what counts as a confined space, what the law expects in the UK, Spain and Gibraltar, and how the different course levels fit together.
What is a confined space?
The UK Health and Safety Executive (HSE) defines a confined space as one that is both enclosed or largely enclosed and has a reasonably foreseeable specified risk to workers. The specified risks are fire, explosion, loss of consciousness, asphyxiation and drowning.
Size is not the test. HSE gives a grain silo of hundreds of cubic metres as an example. Tanks, vats, pits, sewers, tunnels, ducts and voids can all qualify, depending on the hazards inside.
Spanish law uses a similar idea. Real Decreto 39/1997, article 22 bis, describes a confined space as an enclosure with limited openings for entry and exit and unfavourable natural ventilation, where toxic or flammable contaminants can build up or the atmosphere can be oxygen-deficient, and which is not designed for continuous occupation.
What the law expects
United Kingdom
The Confined Spaces Regulations 1997 set three core duties:
- Avoid entry where it is reasonably practicable to do the work another way (regulation 4(1)).
- If entry is necessary, work only under a safe system of work that controls the specified risks (regulation 4(2)).
- Do not enter until suitable and sufficient rescue arrangements are in place. These must reduce the risk to rescuers and, where resuscitation could be needed, include the equipment to do it (regulation 5).
HSE's Approved Code of Practice L101, Safe work in confined spaces (third edition, 2014), explains how to meet these duties. HSE is also clear that it is not enough to rely on the emergency services for rescue.
Spain
Ley 31/1995 de Prevención de Riesgos Laborales requires employers to give each worker sufficient and adequate theoretical and practical training (article 19) and to plan for emergencies, designating trained staff in sufficient number with the right equipment (article 20).
Under Real Decreto 39/1997, article 22 bis, work in confined spaces is one of the activities that requires the presence of a recurso preventivo on site, whose role is to monitor that preventive measures are followed.
The INSST technical note NTP 223 sets out good practice. It describes a written entry authorisation as the basis of every entry plan, and calls for atmosphere testing before and during work, forced ventilation where needed (never with oxygen), an attendant outside in constant contact with the entrant, rescue equipment ready at the entrance, and regular emergency and rescue drills.
Gibraltar
Section 32 of Gibraltar's Factories Act covers work inside any chamber, tank, vat, pit, pipe, flue or similar confined space where dangerous fumes may be present. It requires adequate means of egress, controls on entry (removing fumes and testing, or breathing apparatus), breathing and reviving apparatus kept readily available, and a sufficient number of staff trained and practised in using it.
Why permits matter
A permit to work, or entry authorisation, turns a risk assessment into a set of checks that must be done before anyone goes in. It records who is entering, what has been isolated, what the atmosphere readings are, how long the permit lasts and how the team will be rescued.
Its value is that it forces a pause. Most confined space incidents involve a step that was skipped: an unchecked atmosphere, a valve left open, or no one watching the entrance.
Why rescue plans matter
A rescue plan is written for a specific space, not a site in general. It answers practical questions: how a casualty will be lifted out, who does it, what equipment is at the entrance, how the alarm is raised and how long it all takes.
Untrained, unplanned rescue attempts are a well-known cause of multiple fatalities. The legal duty to have rescue arrangements before entry exists for that reason. A plan only works if the team has practised it.
Course levels
Not everyone needs the same course. The right level depends on the spaces your people actually enter and what your risk assessment says about them. James Daniel Holman delivers the following levels in Gibraltar, Cádiz and on clients' sites:
- Confined Space Entry – Low Risk (1 day, €130 per person): for work in spaces assessed as lower risk, with straightforward access and controlled hazards.
- Confined Space Entry – Medium Risk (1 day, €160 per person): for spaces with more difficult access or greater potential hazards, where additional controls and equipment are needed.
- Confined Space Entry – High Risk (2 days, €350 per person): for the most demanding entries identified by the risk assessment.
- Confined Space Supervisor (2 days, €380 per person): for those who plan entries, issue or control permits and supervise teams.
- Confined Space Rescue (3 days, €550 per person): for teams who will carry out the rescue arrangements required before entry.
Courses run for a minimum of six people; the Supervisor course runs for a minimum of four.
Choosing the right course
Start with your risk assessment. List the spaces, the hazards in each and how people get in and out. Then match people to roles: entrants, attendants, supervisors and rescuers. A supervisor who has never been trained to rescue, or a rescue team that has never practised in your type of space, is a gap.
James is a professional rescue trainer, former firefighter and EMT, and has delivered confined space training to rescue organisations and emergency services. Training can be built around your own spaces and equipment.
This is general guidance, not legal advice.
See course details on the rescue and confined space courses page.
