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NULCA members sensible approach to confined spaces

A NULCA member has highlighted the grey area surrounding confined space issues that seem to be commonly encountered in every work area in the locating environment.

They said that, when in doubt, a common conclusion was that any hole or opening was automatically considered a confined space.


As specified in NSW Work Cover’s Confined Spaces Code of Practice “trenches are not considered confined spaces”.

The issues around trenches are addressed under structural collapse, but may become a confined space in certain environments, which is a new way of thinking about it.

The term ‘likely’

The term ‘likely’ appears on just about every page of Safe Work Australia’s How to Manage Work Health and Safety Risks Model Code of Practice. While it is not clearly defined what the term actually means, the member offers the following as an interpretation.

“If you sat in your car and closed the doors ­– potentially a confined space – is it likely that the environment has low oxygen levels, hydrogen sulphide (H2S), high lower explosive (LEL) levels, and more.

“You might say it’s not likely or even highly unlikely, but possible.

“Is it constructed for a person to occupy? Yes. Could you be engulfed by water? Unlikely, but possible,” they said.

“Now to apply this reasoning around some of the work environments NULCA members are facing in the network.”

However, they stressed that there are many considerations besides gas levels when assessing a confined space:


  • An open vented storm water system is not likely to have gas issues, but it is possible, so conduct gas detection prior to entering but also assess all the other risks.
  • Storm water pipes or small culverts are not meant to occupied, so they would be a confined space; while cleaning or disturbing debris will release H2S, so it too is now considered a confined space.
  • If water levels are enough to drown in then it is a confined space.
  • Other issues, like a pending storm and subsequent water flows, also need to be assessed using a sensible risk assessment.
  • It must also be remembered that some sewers have overflows to the storm water system that can activate with high rainfall or blockages which then relieves into the stormwater.


  • A sewer by nature, on the other hand, is likely to have methane gas, so a sewer manhole would be considered a confined space.

Electrical pits

  • Electrical pits are not likely to have gas issues, but often have high water levels or electrical hazards.
  • These issues make them a confined space, and gas detection is a precautionary measure.

Communications pits

  • Telstra has assessed its network and has predominantly determined their network not to be a confined space.
  • It is unlikely for gas issues to be present in Telstra pits, but as specified in its Health, Safety and Environment Framework for Telstra Suppliers of Services and Products document, workers must use precaution when opening or entering a pit.
  • If gas is not an issue, there may be other issues making the pit a confined space, such as water levels.


The use of a gas detector does not by virtue define a space as confined, it is a precautionary measure.

Telstra has taken a sensible approach in assessing their environment.

Get to know the code relevant to your state to determine your work environment issues.

The NULCA member stressed that the information expressed in this article is an interpretation and that each individual must make their own assessment of a particular confined space.

NULCA said it welcomes its members to provide a response discussing their views confined space issues.

If you would like to express your view on this issue contact NULCA Vice President Natalie Hunter at

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