Most confined space incidents don’t begin with a dramatic failure. They begin with someone deciding the job is quick and the space looks fine. The gas test can wait. No need to wear PPE. That’s the worst thing you can do when working in confined spaces.
Queensland law takes the opposite view, treating a confined space as dangerous until a competent person proves otherwise in writing.
But how do they identify confined space hazards? What classes as a hazard, and what counts as overreacting? This guide names the confined space hazards you are dealing with and how each one gets controlled.
What Counts as a Confined Space Hazard?
Three things make a space a confined space in Queensland:
- It is enclosed or partially enclosed
- It is not intended primarily for continuous human occupancy
- It has restricted means of entry and exit that put workers at risk from its atmosphere or contents.
The hazards involved fall into two groups: atmospheric hazards, and physical hazards.
Atmospheric hazards concern the air itself: unsafe oxygen levels, toxic gases, or flammable gases. They are why a partially enclosed space can be lethal without looking dangerous.
Physical hazards concern the space and what’s inside it, including engulfment risks, moving plant, heat, and restricted access that turns a small problem into a trapped worker.
One exclusion is worth knowing: a mine shaft and the workings of a mine are not confined spaces under the Queensland definition, even though they are enclosed and high risk.
Atmospheric Hazards: Oxygen, Toxic Gases, and Flammable Gases
In Queensland, a safe oxygen level is an oxygen content of between 19.5% and 23.5% by volume (measured at normal atmospheric pressure).
Below 19.5%, judgment and coordination are negatively affected. Above 23.5%, you’re faced with a different problem: fire and explosion risk. This is because an oxygen-enriched atmosphere makes materials ignite far more readily than they would in fresh air.
Many toxic gases give no warning. Hydrogen sulphide is the most deceptive, because it smells strongly at low concentrations, then deadens the sense of smell at the concentrations that actually kill. Carbon monoxide has no smell at all.
With flammable gases, the concentration of any flammable gas, vapour, or mist has to stay below 5% of its lower explosive limit, known as the LEL.
Physical Hazards and Engulfment Risks
Engulfment risks are the hazard most often underestimated. Grain, sand, sludge, and liquids behave like quicksand once they start moving, and a worker standing on a crust of settled material can drop through it without warning. Opening a discharge valve while someone is inside changes the space in seconds.
The other physical hazards are less exotic and just as serious. Augers that restart on a timer, hot work, extreme heat inside an unventilated tank, and access too restricted for a stretcher extraction all belong on the risk assessment.
Control Hazards Before Anyone Enters
Under Queensland’s Work Health and Safety Regulation 2011, a risk assessment for health and safety in a confined space must be carried out by a competent person and recorded in writing. That record informs the entry permit’s control measures.
The first question a risk assessment must ask is whether the work can be done without entering the space at all. That’s the one control that removes every hazard at once, and it’s a legal consideration, not merely a good habit. Examples include camera inspection, external cleaning, and vacuum equipment operated from outside.
The Confined Space Entry Permit
Nobody can be directed to enter until a confined space entry permit has been issued. The permit must be in writing, completed by a competent person, and it must state four things: the space it covers, the names of the people allowed to enter, the period the work runs for, and the control measures in place.
It must also carry an acknowledgement that the work is finished and every person has left. That closing sign-off is the step most often skipped, and it is the only formal check that nobody is still inside.
Signs go up at each entry before work starts, identifying the space and telling workers not to enter without a permit. That is the control against someone wandering in.
Atmospheric Testing and Air Quality
Air quality is tested before entry and monitored while work continues, because conditions change as the job changes. Welding, coating, and simply disturbing sludge can each move a space from safe to hazardous within minutes.
The flammable gas thresholds set the response. Between 5% and 10% of the LEL, workers must be removed unless a suitably calibrated continuous-monitoring gas detector is in use. At 10% or above, they come out immediately and no monitoring exception applies.
Where oxygen content cannot practicably be brought back into the safe range, work does not simply proceed with extra care. Anyone working in the space must be issued air supplied respiratory equipment.
Ventilation, Isolation, and Fresh Air
Mechanical ventilation is the usual way to purge airborne contaminants and hold breathable air in the space. Natural ventilation is not a control measure, because it cannot be verified, adjusted, or relied on.
One rule catches people out. Pure oxygen, or any gas mixture above 21% oxygen, must never be used to purge or ventilate a confined space. It feels like the obvious fix for poor air quality, and it creates an oxygen-enriched atmosphere that turns the space into a fire risk.
Isolation deals with everything connected to the space. Plant and services must be secured so nothing can be introduced and nothing can be activated or energised while a worker is inside. In practice that means locking out agitators, blanking lines, and de-energising circuits rather than trusting a switch.
Standby, Rescue Procedures, and Emergency Response
Nobody enters alone in any meaningful sense. There must be continuous communication with the worker from outside the space, plus a standby person nearby monitoring conditions and, where practicable, watching the work.
Rescue procedures have to be established and practised, not written once and filed. The regulation is blunt about how they start, because first aid and rescue procedures must be initiated from outside the confined space as soon as practicable. Entry and exit points must also be large enough for emergency access and kept unobstructed.
A rescuer entering an atmosphere without a safe oxygen level, or one holding harmful concentrations of airborne contaminants, must be provided with air supplied respiratory equipment. A rescue attempt made on instinct without equipment tends to produce a second casualty instead of saving the first.
Confined Space Training and Competency
Every duty described here rests on a competent person. Someone assesses the risk, someone completes the permit, someone tests the atmosphere, and someone stands by outside. Competence is what is regulated, and confined space training is how an employer demonstrates it.
RIIWHS202E Enter and Work in Confined Spaces is the nationally recognised unit covering safe entry procedures, gas detection equipment, exit procedures, and rescue plans. Employers carry the duty to provide it, and most of the confined space duties above run to a maximum penalty of 60 penalty units each.
Get Confined Spaces Training with an RTO
The best way to mitigate risk and dangers while working in confined spaces is to employ someone with the right training from a Registered Training Organisation (RTO).
Major Training delivers confined space training and refresher courses across Queensland and NSW, along with working at heights for crews who need both tickets in the same visit.
Talk to our team about getting your crew ticketed.
Frequently Asked Questions
Who is allowed to complete a confined space entry permit?
A competent person, meaning someone with the training, knowledge, and practical experience to make the call. It has to be written down and built on the recorded risk assessment for that space, so it cannot be filled in from memory or carried over from a previous job.
Is confined space training needed by someone who never enters the space?
Often, yes. The training duty covers relevant workers, and that includes people who issue permits, act as the standby person, monitor conditions from outside, or buy equipment for the work. Staying outside does not put you outside the training requirement.
Do emergency services need a permit to enter a confined space?
No. Emergency service workers rescuing someone or providing first aid at the direction of their organisation are exempt from the permit and signage requirements. The exemption does not extend to workers on site, who remain bound by the rescue procedures for the space.
Is hot work allowed in a confined space?
Only where the risk of ignition has been assessed and controlled, because an ignition source must not be introduced where it could cause a fire or explosion. Hot work also changes the atmosphere as it proceeds, raising the testing and ventilation requirements.
Get your crew confined space certified
Major Training runs nationally recognised confined space training at our Queensland locations or on your site, with real gas detection and rescue practice.
