Crowcon - Detecting Gas Saving Lives
08 January 2015
Revised Confined Space Regulations published by Health & Safety Executive

The UK Health & Safety Executive (HSE) has recently revised its Confined Space Regulations ‘Approved Code of Practice’ document, so I thought this would be a good opportunity to review the guidance in relation to gas detection.

The Approved Code of Practice (ACOP) provides practical advice on how you can comply with the requirements of the Confined Spaces Regulations 1997.

What does confined space mean?

A confined space is a place which is substantially enclosed, and where serious injury can occur from hazardous substances or conditions within the space or nearby (e.g. lack of oxygen). However, a confined space is not always substantially enclosed and can include places, such as chambers, tanks, vats, silos, pits, trenches, pipes, sewers, flues, wells or any other similar space where a reasonably foreseeable specified risk arises.

Many confined spaces are easy to identify, such as sewers and closed tanks, but understanding whether other places could be classed as a confined space can be a little trickier. A place not usually considered to present confined space hazards may become one. For example, work , such as welding, a spray booth or using chemicals for cleaning purposes, can introduce risks to an enclosed space normally considered free of contaminants and to have a safe level of oxygen.

Some spaces may meet the criteria of a confined space when they are used to store certain specific items, such as gas cylinders, material used as part of a fire suppression system or a storage facility for wooden pellets used as fuel in heating systems. Other confined spaces may be created deliberately, for example reduced oxygen environments, where the oxygen level is depleted either by reducing the oxygen concentration or increasing the concentration of another gas, such as nitrogen.

What should you assess to establish a confined space?

Determine the general condition of the confined space, to identify what might be present or not, and what could cause a problem.

  • Information about any substances previously held will give an indication of what kind of hazard may be expected.
  • Dangers that may arise from chemical residues or scale, rust, sludge or other residues must be considered.
  • Contamination that may arise from adjacent plant, processes, gas mains or surrounding land, soil or strata. Gases and liquids may leak, or may have leaked into the confined space.
  • In certain situations, water and/or gases may enter the confined space from the surrounding land, soil or strata.
  • Methane can occur from a number of sources, including the decay of organic matter, and can be released from groundwater.
  • There are substantial risks if the concentration of oxygen in the atmosphere varies significantly.
  • Particular care should be taken in environments created with a specifically reduced oxygen concentration in the atmosphere.

Ensuring personal protective equipment (PPE) is used upon entering a confined space.

HSE’s document explains the importance of personnel wearing PPE when entering a confined space, whether its an employer providing for their employee, or self-employed. PPE must also be fully maintained on a regular basis.

To properly assess confined space hazards in your workplace, or to simply learn about the updates to the document, you can download it, for free, from the Health & Safety Executive website –

Subscribe to our blog

Join our mailing list to receive the latest blog!

    Read about Crowcon’s Privacy and Cookie policy here. If you change your mind, you can unsubscribe at any time.