Simply Put – Confined Spaces

Confined spaces tend to cause a more confusion that you would think. Everyone knows what one is, until you ask them to define ne.

A confined space is a place which is substantially enclosed (though not always entirely), and where serious injury can occur from hazardous substances or conditions within the space or nearby (e.g. lack of oxygen).

What are confined spaces?

It can be any space of an enclosed nature where there is a risk of death or serious injury from hazardous substances or dangerous conditions (eg lack of oxygen). Some confined spaces are fairly obvious are are easy to identify, eg enclosures with limited openings:

• storage tanks
• silos
• reaction vessels
• enclosed drains
• sewers

However, some other confined spaces may be less obvious, such as:

• open-topped chambers
• vehicle inspection pits
• vats
• combustion chambers in furnaces etc
• ductwork
• unventilated or poorly ventilated rooms
• some cellars

It is not possible to provide a comprehensive list of confined spaces. Some places may become confined spaces when work is carried out, or during their construction, fabrication or subsequent modification.

Confined Spaces risk assessment

Key duties under the Confined Spaces Regulations 1997 Regulations:

• Avoid entry to confined spaces
• If entry cannot be avoided, follow a safe system of work
• Put in place adequate emergency arrangements before work commences

Like all aspects of modern health and safety, risk assessment is at the centre of confined spaces entry. This requirement is identified in both the Confined Spaces Regulations 1997 and in the Management of Health and Safety at Work Regulations 1999. For work in confined spaces this means identifying the hazards present, assessing the risks and determining what precautions to take. In most cases the assessment will include consideration of:

• the task
• the working environment
• working materials and tools
• the suitability of the people carrying out the task
• arrangements for emergency rescue

Confined Spaces – hazards

• Flammable substances
  • Leak from a gas cylinder (acetylene, LPG)
  • Leak from gas mains
  • Fumes from nearby LPG store, highly flammable liquids store, fuel store, etc.
  • Solvents from paints or cleaning materials, etc.
• Oxygen enrichment
  • Leak from a welding set
  • Leak from nearby (cryogenic) oxygen store
• Toxic gas, fume or vapour
  • Previous processes
  • Sludge deposits
  • Cleaning operations
  • Sewers, etc.
  • Welding operations
  • Paints and resins
• Oxygen deficiency
  • Purging with inert gas to remove flammable or toxic gas
  • Biological processes consuming oxygen
    • Sewers, storage tanks, storm water drains, wells, etc.
  • Biological processes producing carbon dioxide
    • Grain storage silos, brewing vessels, cargo holds, etc.
  • Leaving vessels closed for long periods
    • –Rust formation consuming oxygen
  • Increased carbon dioxide levels from limestone chippings, burning operations, welding operations
  • Use of liquid nitrogen for pipe freezing
  • Gradual oxygen depletion from workers breathing in a confined space where provision of replacement air is inadequate
• Ingress or presence of liquids
  • Liquids that can flow into the confined space leading to drowning and other serious injury depending on the nature of the liquid (such as toxicity or corrosiveness)
• Solid materials that can flow
  • Free flowing solids can submerge a person, preventing breathing.
  • Grain, sugar, flour, sand, coal-dust and other substances in a granular or powder form
• Presence of excessive heat

  • Work in hot conditions

  • Boilers or furnaces which have not been allowed sufficient time to cool
  • Steam cleaning operations to remove hydrocarbons

We also offer Confined Spaces Awareness training – call us on 01509 550023