Confined spaces

What are confined spaces exactly?

We regularly come across the term ‘confined space’, but what is and what isn’t a confined space?

Below is some general information about confined spaces, but not a generally applicable instruction manual as to what should be considered a confined space. The subject is simply too complex.

One definition:

‘A confined space is an enclosed or partially open area with one or more narrowed accesses that is not designed for people to stay in.
Under ‘normal’ conditions, a confined space is usually sealed against people passing by, but it is entered occasionally or regularly for inspections, repairs, cleaning and maintenance that involve risks in the areas of safety, health and well-being.’

Characteristics

Confined spaces have some important characteristics.

  • A confined space is a workplace with difficult access, even for emergency workers.
  • Confined space are generally small, but this is not always the case.
  • When a confined space is taken out of operation, hazardous substances may remain, so dangerous concentrations may be present during the work.
  • A space can also be labelled as a confined space if it is difficult to access, and consequently difficult to evacuate and rescue people.
  • Poor ventilation and no daylight are other common characteristics.
  • The position of workers is also often less than ideal.

Examples of confined spaces

  • Cellars
  • Tankers
  • Storage reservoirs (basins)
  • Sewers
  • Crawl spaces
  • Inspection manholes
  • Trenches with pipelines
  • Boilers
  • Excavations
  • Gas containers and storage tanks
  • Pipelines
  • Pressure vessels
  • Pump wells
  • Cooling towers

High-risk activities:

  • Welding and grinding
  • Blasting
  • Conservation
  • Electrical work
  • Cleaning work
  • Diving

Possible dangers:

  • Asphyxia
  • Drowsiness or poisoning
  • Fire or explosion
  • Dust explosion
  • Congestion
  • Flooding
  • Fall when working at height
  • Slipping
  • Falling objects
  • Evaporation of residual materials or rust layers
  • Moving or protruding machinery and other parts
  • Unintended release of energy
  • Little space for movement
  • Limited escape options
  • Presence of live electrical components
  • Difficult to ventilate
  • Drowning

Prior to entering confined spaces, a risk inventory and evaluation must be carried out. For this, use the ‘Checklist AI-5 confined spaces’, which can be found under ‘Publications’.

At Uniper Benelux BV, a ‘High-level Work Permit’ is always required before entering a confined space.