Confined space
Also known as: Confined spaces
A confined space is a largely enclosed place where there is a foreseeable risk of serious injury from hazardous conditions such as lack of oxygen or gas.
- A largely enclosed space with a foreseeable risk of serious injury.
- It is defined by the hazard inside it, not by how small it is.
- Entry needs a safe system, trained people and workable emergency arrangements.
A confined space is a place that is substantially enclosed and where there is a reasonably foreseeable risk of serious injury from hazardous conditions inside it. Tanks, chambers, sewers, ducts, pits, silos, some excavations and some voids all qualify.
The definition catches people out because it has nothing to do with size. A large tank is a confined space. A small, well ventilated store with nothing dangerous in it is not. What matters is enclosure plus one of the specified risks: gas, fume, vapour, lack of oxygen, fire or explosion, rising liquid, free-flowing solids, or heat sufficient to cause loss of consciousness.
The duties, in order
Avoid entry. The first duty in the regulations is not to enter at all if the work can reasonably be done from outside. Remote inspection, cleaning in place, camera survey. This is the top of the hierarchy of control and it removes the risk rather than managing it.
If entry is unavoidable, use a safe system of work. Atmospheric testing before and during entry, ventilation, isolation of incoming services and materials, trained and competent people, communication with the outside, and a person stationed at the entry point.
Have workable emergency arrangements before anyone goes in. Not a plan to call the fire service and hope. Rescue equipment on hand, people trained to use it, and a method that does not require a rescuer to enter unprotected.
Why rescue is the critical part
The pattern in fatal confined space incidents is grimly consistent: one person is overcome, and colleagues who go in to help are overcome too. The atmosphere that caused the first casualty does not clear because someone else has entered it.
That is why the emergency arrangements have to be resourced before entry rather than improvised. It is also why a permit to work is the standard control here. The permit is the point at which someone independent confirms the testing was done, the isolations are in place, and the rescue provision is actually standing by.
Where hot works happen inside a confined space, the two sets of controls stack rather than replacing one another, and the fire and atmosphere risks interact.
The record
Entry training, medical fitness where required, gas monitor calibration certificates, the method statement and each issued permit all need to be producible. Keeping them against the project and the person, with the expiries visible, is what Sync’s risk management and credential management are built for.
Common questions
Does a space have to be small to be a confined space?
No, and this is the most common misunderstanding. The definition turns on the space being largely enclosed and on there being a foreseeable specified risk inside it. A large tank, a grain silo or a section of sewer are all confined spaces. A cramped but well ventilated cupboard with nothing hazardous in it is not.
What are the specified risks?
Serious injury from fire or explosion, loss of consciousness from raised body temperature, loss of consciousness or asphyxiation from gas, fume, vapour or lack of oxygen, drowning from rising liquid, and asphyxiation from a free-flowing solid such as grain or sand.
Why do rescuers so often become casualties?
Because the atmosphere that overcame the first person is still there, and instinct sends colleagues in after them without protection. It is a well documented pattern in fatal confined space incidents, and it is why the emergency arrangements have to be worked out and resourced before anyone enters, not improvised afterwards.
Is a permit always needed?
Not universally required by name, but for anything beyond the most trivial entry it is the accepted control, and its absence would be very difficult to justify. The permit is what confirms the atmosphere was tested, the isolations are in place and the rescue arrangements are standing by.
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