Confined spaces may pose a danger because they are not designed to be areas where people work. Hazards are not always obvious, may change and the risks include loss of consciousness, impairment, injury or death.
Many workplaces have confined spaces such as pits, drains and structural voids in buildings or equipment. They often have poor ventilation that can allow a hazardous atmosphere to quickly develop. The hazards are not always obvious, may change from one entry into the confined space to the next and depend on the workplace or environmental circumstances.
What is a confined space?
A ‘confined space’ is defined as an enclosed or partially enclosed space that:
- is not designed to be occupied by a person, and
- is intended to be at normal atmospheric pressure while any person is in the space, and
- is or is likely to be a risk to health and safety from—
- an unsafe oxygen level, or
- contaminants, including airborne gases, vapours and dusts, that may cause injury from fire or explosion, or
- harmful concentrations of any airborne contaminants, or
Confined spaces can be found in vats, tanks, pits, pipes, ducts, flues, chimneys, silos, pressure vessels, underground sewers, wet or dry wells, shafts, shipboard spaces, void spaces or other similar enclosed or partially enclosed structures.
When working in confined spaces, there are serious health and safety risks, for example:
- loss of consciousness, injury or death from contaminants in the air
- a fire or explosion that kills or seriously injures
- suffocation from oxygen deficiency
- crushing or suffocation from something like grain, sand, flour or fertiliser if you fall into it
Incidents in confined spaces have sometimes involved multiple deaths. Other workers enter a space to rescue a victim, unaware of the risks. However, they can also be overcome by toxic fumes or gases.
What is not a confined space
The following kinds of workplaces are also generally not confined spaces:
- a mine shaft or the workings of a mine
- places intended for human occupancy
- some enclosed or partially enclosed spaces that have harmful airborne contaminants but are designed for a person to occupy, for example abrasive blasting or spray-painting booths
- enclosed or partially enclosed spaces that are designed to be occasionally occupied by a person for example, a fumigated shipping container or a cool store.
There are many legislative requirements that are applied to confined spaces.
For designers, manufacturers, importers, suppliers, installers and constructors of plant and structures
You must eliminate the need for anyone to enter a confined space and eliminate the risk of inadvertent entry. Where this is not possible you must:
- minimise the need for people to enter the space
- make sure it has safe entry and exits
- minimise (or where you can, eliminate) the risks to the health and safety of anyone who enters the space.
Manage the risks
A written risk assessment must be completed prior to entry by a competent person with the right knowledge and skills, of all the possible risks of entering, or working in or near, a confined space. That person needs to review and revise it when necessary, and include:
- whether the work can be carried out without the need to enter the space
- the nature of the space
- the hazards associated with the space
- how the work can be done, and
- the emergency response procedures.
Get an entry permit
Everyone needs a permit to enter the space. It must be written by a competent person and needs to state:
- which space it relates to
- the name of the person permitted to enter
- the time the work will be done
- control measures for the associated risks for entry and while working
- a section for the competent person to acknowledge that everyone has left the space.
Permits ensure a safe system of work is in place and ensures communication between site management, supervisors and those carrying out the work.
Put up signs
Before work begins signs must be put up to prevent entry by unauthorised people. Security devices, such as locks and fixed barriers, should be installed. Signs must be in place while the confined space is accessible, including when preparing and packing up.
Where practical, confined spaces should be permanently signposted and comply with Australian Standard AS 1319:1994 Safety signs for the occupational environment.
Communicate and monitor
A stand-by person must continuously monitor the conditions from outside the space, and where they can, observe the work being carried out. You must be able to order the workers to get out, communicate with them at all times, and start emergency procedures when necessary. The stand-by person must never enter the space to attempt a rescue.
Practice your emergency procedures
Establish first aid and rescue procedures and practice them so that they are effective in an emergency.
Check the entry and exits are large enough to allow emergency access and are not obstructed. Also, make sure all plant, equipment and PPE used for first aid or rescue are maintained in good working order.
Inform, train and instruct your workers
Workers and supervisors must be provided with suitable and adequate information, training and instruction to understand the risks, the controls in place, what work the permit allows them to do, correct use of PPE and what to do in an emergency.
Records must be kept for the following minimum durations:
- training records – two years
- risk assessment - 28 days after the work to which it relates is completed
- confined space entry permit - until the work to which it relates is completed
- notifiable incident - all records must be kept for two years after the incident.
All these records must be made available to us and any worker upon request.
Isolate plant and services
Minimise or, if you can, eliminate the risks from plant or services connected to the space from:
- introducing any contaminants or substances into the space
- activating in the space, or
- energising the space.
Clear the atmosphere
Keep the space well-ventilated and safely purge any contaminants. You should carry out atmospheric testing before anyone enters and use an appropriate respirator if you are unable to keep safe oxygen levels.
Get rid of all ignition sources
Get rid of all ignition sources that could cause a fire or explosion. Ensure the amount of flammable gas, vapour or mist in the space is less than five per cent of its lower explosive limit (LEL). If the LEL is greater than five but less than 10 per cent, you must use a flammable gas detector. If the LEL is greater than 10 per cent, no-one should be in the space.
Technical help and resources
An example of a confined space entry permit can be found in Annex C of the Code of Practice: Confined Spaces August 2019
- Work Health and Safety Act 2011 No 10
- Work Health and Safety Regulation 2017: Part 4.3 Confined Spaces
- SafeWork NSW: Code of Practice: Confined Spaces August 2019
- AS 2865-2009 Confined Spaces
- AS 1319-1994 Safety signs for the occupational environment
- AS/NZS 1715: 2009 Selection, use and maintenance of respiratory protective equipment.
- Safe Work Australia: Confined spaces
- SafeWork NSW: Confined space analysis and emergency plans
- SafeWork NSW: Code of Practice: Managing the work environment and facilities August 2019
- SafeWork NSW: Code of Practice: Hazardous manual tasks August 2019
- SafeWork NSW: Confined space analysis and emergency plans
- SafeWork NSW: Hazardous Chemicals