A confined space is any enclosed or partially enclosed place where dangerous conditions may exist due to limited access, poor ventilation, or the presence of harmful gases. On construction sites, confined spaces include manholes, tanks, culverts, deep excavations, and chambers. Entry without proper precautions has caused multiple fatalities, often killing rescuers too.
Key Hazards
Oxygen depletion causing rapid loss of consciousness and death
Toxic or flammable gas accumulation in enclosed areas
Drowning from sudden ingress of water or liquid materials
Entrapment from free-flowing solids such as grain or sludge
Control Measures
Avoid entry into any confined space unless absolutely necessary and no alternative method exists.
Ensure a confined space risk assessment is completed before any entry takes place.
Obtain a valid confined space entry permit signed by an authorised person before entering.
Test the atmosphere using calibrated gas detection equipment before and during entry.
Provide forced ventilation to maintain safe oxygen levels and disperse harmful gases.
Ensure a trained top man or entry controller is stationed at the entry point at all times.
Establish reliable communication between the entrant and the top man throughout the task.
Isolate all mechanical, electrical, and pipework systems connected to the confined space.
Have rescue equipment including tripod, winch, and breathing apparatus ready before entry begins.
Emergency / Rescue
Never enter a confined space to rescue someone without breathing apparatus and a rescue plan. Raise the alarm, call 999, and use the tripod and winch system. Untrained rescue attempts cause additional deaths.
Remember
A confined space does not have to be small — any area with restricted access qualifies.
You cannot see or smell many of the gases that can kill in confined spaces.
Never enter a confined space without a valid permit and atmospheric testing completed.
Failed rescue attempts are the most common cause of multiple deaths in confined spaces.
If your gas monitor alarms, leave the space immediately and report to your supervisor.
Applicable Legislation: Confined Spaces Regulations 1997 · Health and Safety at Work etc. Act 1974 · Management of Health and Safety at Work Regulations 1999