Confined spaces present difficult access challenges and can be hazardous places to work in. That’s why it’s so important to be able to identify a confined space and manage any associated health and safety risks.
Need help? Height Dynamics can provide a Site Assessment and Auditing Service to assist with identifying confined spaces and developing a confined space register – plus access and rescue procedures. Just give us a call or send an email to [email protected]
Four key characteristics of a confined space
Under the Safe Work Australia model and Australian Work Health and Safety Regulation 5, a confined space must meet the following four criteria:
- Either fully or partially enclosed; and
- Not designed primarily for human occupation; and
- Designed to be at a normal atmospheric pressure; and
- Contains at least one of the following health and safety hazards:
- an atmosphere with unsafe oxygen levels
- a contaminant (gases, vapours, dusts) that may cause injury from fire or explosion
- harmful concentrations of an airborne contaminant
- the potential for engulfment
There are some circumstances where your space could turn into a confined space (even it it doesn’t ordinarily meet all of the above criteria) – for example:
- By adding temporary walls or elements that either fully or partially enclose the space
- By storing, using or bringing potential contaminants into the space (even if temporarily)
- By temporarily bringing the space to normal atmospheric pressure (prior to entry/use)
- By neglecting to fix failing ventilation within a space, thus compromising oxygen levels
Common examples of confined spaces
Here’s some examples of confined spaces you might come across as part of your work, profession or industry:
Storage tanks and bins; pressure vessels; pipes and boilers; sumps and pump hoppers; abandoned tunnels or shafts; degreasing pits; wet and dry wells; excavation holes and trenches; refrigeration units; tanks or vats; wheel motor housings; industrial silos; sewers.
Note: Under Australian Work Health & Safety Regulations, a mine shaft is not designated a confined space.
Your confined space checklist
Want to know if your site could be designated a confined space? Let’s use the following checklist to explore each characteristic further.
1. Is your space either fully or partially enclosed?
Fully or partially enclosed spaces pose a risk because they typically severely restrict access. And access restrictions aren’t good at the best of times, let alone when trying to evacuate or perform a rescue in a confined space.
For example, a space that’s mostly enclosed with just a single, small opening will severely restrict your ability to enter and exit the space quickly and easily. And if that opening is located in a dangerous or physically difficult to reach location, it will also make access complex and unsafe.
2. Is your space not primarily designed for human occupation?
A space not made for humans is typically not safe for humans!
Confined spaces – such as sewers, tanks, drains, vessels, chimneys – aren’t designed primarily for human occupation. As such, they’re typically not well ventilated, which can present serious problems to anyone who has to enter the space to complete work.
It doesn’t take long to overheat, dehydrate and become incapacitated. And without specialist training and equipment, any oxygen deficiencies in the environment could quickly render someone unconscious or even lead to asphyxiation.
So here’s a good rule of thumb to apply – if you need an oxygen mask to go in, it’s a confined space red flag.
3. Is your space designed for use at normal atmospheric pressure?
A confined space is typically designed for use at normal atmospheric pressure.
Where a space is not typically at normal atmospheric pressure (such as a boiler) but must be bought to normal atmospheric pressure before a person can enter the space – it may temporarily qualify as a confined space and should be treated as such.
4. Does your space contain any of these health and safety risks or hazards?
|Unsafe oxgen levels
|Air with an oxygen content of between 19.5 – 23.5% is considered to have a safe oxygen level. If your oxygen content is outside of that range, it is deemed unsafe.
|Potentially hazardous contaminants (including airborne gases, vapours and dusts) that may cause injury from fire or explosion.
|Harmful concentrations of airborne contaminants
|If any airborne contaminants are present within the environment, you must investigate further. There are different concentration levels at which each contaminant may present an unsafe exposure. You should also identify any circumstances under which the contaminant could cause impairment, loss of consciousness or asphyxiation.
|Harmful combinations of airborne contaminants
|It’s also important to consider combinations of contaminants within a space. Especially important is whether any flammable components could be ignited and present a fire and smoke inhalation or explosion risk.
|Any potential for engulfment
|Engulfment risk should take into account any liquid (including oil or water) in which a person can drown. Your risk assessment should also consider solids (such as grain, fly ash, sawdust and sand) that could flow within the space to form a temporary cavity or bridge which may ultimately collapse and surround a person, cutting off their air supply.
Three things you need to work in a confined space
1. You must have a permit to work in any confined space
Confined spaces are not normal workplaces. In fact, you cannot legally enter let alone work in a confined space without a Confined Space Entry Permit. A PCBU must not allow or direct a worker to enter a confined space to carry out work unless that worker has been issued a confined space entry permit for the work. Permits must be completed by a competent person.
To obtain such a permit, your site must meet the above criteria and be officially designated a confined space.
Identification and Registration
- All confined spaces that personnel may need to enter must be identified. The identification must be based on the detailed definitions of confined spaces, as per the relevant regulations and Australian Standards.
- All confined spaces must be registered in the Confined Spaces Register or Hazard Register.
In addition, all permit holders must have completed professional, industry-recognised confined space training and be able to use specialist equipment (refer below).
2. You must have completed specialist confined space training
The completion of professional, industry-recognised confined space training is a pre-requisite to obtaining a permit to work in a confined space. If you haven’t already completed this training, you can typically do so with a relevant industry body or your local height safety specialist.
At Height Dynamics, we offer two confined space training courses – both of which are industry-recognised and run by experienced confined space professionals.
|Enter and Work in Confined Spaces
|Operating Breathing Apparatus
|Course covers standby personnel responsibilities, monitoring risks and hazards, and how to work in accordance with a permit. It also heavily focuses on practical skills needed to work in a confined space using different processes and equipment
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|Learn how to safely operate a breathing apparatus as part of your job. By the end of training, successful attendees will have the skills and knowledge to complete pre-operational checks, adjust, fit, operate and maintain a compressed air breathing apparatus
Learn More >
3. You must have the right specialist confined space equipment
To enter and work safely in a confined space safely, you must also be in possession of the right specialist confined space equipment. This is required to mitigate any health and safety risks associated with working in the site.
The exact equipment you need will depend on your site, the risks and work to be undertaken. Check out our Confined Space Collection to see examples of the types of equipment you may need.
If in doubt, always consult with a confined space expert.