HAZARDS ASSOCIATED WITH CONFINED SPACES

The objective of The Confined Spaces Regulations (1997) specify requirements and prohibitions to protect the health, safety and welfare of persons working in confined spaces and also those who may be affected by the work. The definition of “confined space” is very wide and includes any place such as trenches, vats, silos, pits, chambers, sewers, wells or other similar spaces which because of their nature could give rise to a “specific risk”.

A “confined space”has two defining features: first, such a space is substantially (although not necessarily) closed and, second, there is a foreseeable risk from hazardous substances or conditions within the space. A “specified risk” includes injury from fire or explosion, loss of consciousness through a rise in body temperature, or by asphyxiation; drowning; or free-flowing solids causing asphyxiation or preventing escape from a space.

Likely hazards include:

• Flammable substances, either from the contents of the space or nearby area;
  
• Oxygen enrichment, e.g. from a leaking welding cylinder;
  
• Ignition of airborne contaminants;
  
• Fumes or sludge remaining form previous processes or contents; these may release toxic or flammable gases when disturbed;
  
• Oxygen deficiency, which can result: from inert gas purging; from natural biological process such as rusting, decomposition or fermentation;
  
• Liquids entering the space from elsewhere, and solid materials which can flow into it; and
  
• Heat exhaustion caused by working in the confined space of from nearby process.

The factors to be considered in designing a safe system of work, and which may form the basis for a “permit-to-work”, will depend on the “risk assessment” findings and should include:

• Emergency arrangements - act as a back up if the existing controls fail or an unexpected event happens putting the lives of workers in immediate danger;
  
• Communications - any emergency arising within the confined space must be communicated to a surface observer, when work is undertaken below ground level as to allow rescue procedures, if required to begin immediately;
  
• Rescue and resuscitation equipment - where such equipment is provided for use by rescuers, training in correct procedures is essential.
  
• First-aid procedures - trained first-aiders must be on hand to make proper use of any necessary first-aid equipment provided;
  
• Local Emergency services - emergency plans should be discussed with the local fire, police and ambulance services so that the best use can be made of their expertise and facilities.

Better work planning or a different approach can reduce the need for confined space working. The questions that should be asked are:

• Is the intended work in the confined space really necessary?
  
• Could the confined space be modified to make entry unnecessary?
  
• Could the work be performed outside the confined space using appropriate equipment and tools?
  
• Could remote cameras be used for internal inspection of vessels?
  

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