Confined spaces

A confined space includes any enclosed or partially enclosed space that:

• is not designed or intended primarily to be occupied by a person
• is, or is designed or intended to be, at normal atmospheric pressure while a person is in space
• is, or is likely to be, a risk because of the atmosphere, contaminants or engulfment.

A confined space is determined by the hazards associated with specific circumstances and not just because work is performed in a small space.

Entry into a confined space means a person’s head or upper body is in the confined space or within the boundary of the confined space.

Confined spaces are commonly found in vats, tanks, pits, pipes, ducts, flues, chimneys, silos, containers, pressure vessels, underground sewers, wet or dry wells, shafts, trenches, tunnels or other similar enclosed or partially enclosed structures when these examples meet the definition of a confined space in the Work Health and Safety (General) Regulations 2022 [WHS Regulations]. 

A confined space is determined by the structure and hazards associated with the work being carried out. For example, a space may become a confined space if work to be carried out in the space would generate harmful concentrations of airborne contaminants.

For a confined space to be classified as a non-confined space, the structure and its use needs to have undergone sufficient change in order to eliminate all the hazards that defined it as a confined space. Temporary control measures measures such as providing temporary ventilation or achieving a satisfactory pre-entry gas test will not be sufficient for a confined space to be classified as a non-confined space.

A person conducting a business or undertaking (PCBU) must manage the risks associated with a confined space at their workplace. The Confined spaces: Code of practice guides how to manage the risks associated with confined spaces in the workplace using a systematic process. 

PCBUs have a duty to consult workers about work health and safety and consult, cooperate and coordinate with other duty holders.

A reference to a PCBU in the WHS Regulations is deemed a reference to a mine operator where that is relevant. For further guidance, see the The meaning of ‘person conducting a business or undertaking’ (PCBU): Interpretive guideline.

Duties with confined spaces include:

• managing health and safety risks associated with a confined space, including risks when entering, working in, on or near a confined space, and the risk of inadvertent entry, following requirements for managing risks to health and safety set out in Part 3.1 of the WHS Regulations
• ensuring a risk assessment is conducted, reviewed and, as necessary, revised by a competent person
• not directing a worker to enter a confined space unless the worker has an entry permit
• erecting signs next to each entry to the confined space
• ensuring that a worker does not enter a confined space until all the duties in relation to the confined space have been complied with, for example, meeting entry permit requirements
• establishing first aid and rescue procedures to be followed in the event of an emergency in the confined space and ensuring these procedures are practised as necessary
• provide suitable and adequate information, training and instruction to workers.
• the WHS Regulations set out requirements for specific control measures within the confined space including communication and safety monitoring, signs, isolation of connected plant and services, and controls to maintain a safe atmosphere.

PCBU should ensure that people working in a confined space are safe by:

• placing a stand-by-person outside the confined space to talk to anyone in the confined space and implement emergency procedures if required
• providing personal protective equipment and rescue, first-aid and fire suppression equipment
• providing training
• supplying safety harnesses and safety (or rescue) lines where there is a danger of falling while entering or leaving the confined space
• erecting signs that show entry is only permitted after signing the entry permit
• ensuring the area is well-ventilated.

Workers and their supervisors must be provided with suitable and adequate information, training and instruction. Hence, they have the skills and knowledge to understand the hazards associated with working in a confined space, the contents of any confined space entry permit, and the control measures implemented for their protection.

The information, training and instruction provided to relevant workers must cover:

• The nature of all hazards associated with a confined space
• The need for and appropriate use of risk control measures
• The selection, fit, use, wearing, testing, storage and maintenance of any PPE
• The contents of any relevant confined space entry permit
• Emergency procedures

Records of all training provided to workers in relation to confined space work must be kept for two years.

The principal contractor for a construction project has a specific duty under the WHS Regulations to document, in their WHS management Plan for the project, the arrangements in place for consultation, cooperation and coordination between the PCBUs at the site.

Workers must take reasonable care for their own health and safety and not adversely affect other persons' health and safety. Workers must comply with reasonable instructions, and cooperate with health and safety policies or procedures, including information, instructions and training in relation to work carried out by the worker in a confined space. 

Suppose personal protective equipment (PPE) is provided. In that case, the worker must use or wear it following the information, instructions and training provided.

Some requirements for entry permits and signage do not apply to entry into a confined space by an emergency service worker if the worker rescues or provides first aid to a person in a confined space at the direction of the emergency service organisation.

The first step in the risk management is identifying all hazards associated with confined spaces. This involves finding things and situations which could potentially cause harm to people.

Hazards may be identified by looking at the workplace and how work is carried out. It is also useful to talk to workers, manufacturers, suppliers and health and safety specialists and review relevant information, records and incident reports.

The types of substances previously stored in a confined space (however briefly) will indicate the sorts of hazards that may be present. Substances stored in a confined space may result in a lack of oxygen, airborne contaminants or a flammable atmosphere within the confined space.

Other hazards may arise from work activities, products or by-products in or around the confined space.

Hazards associated with a confined space

• Restricted entry or exit
• Harmful airborne contaminants
• Unsafe oxygen level
• Fire and explosion
• Engulfment
• Uncontrolled introduction of substances
• Biological hazards
• Mechanical hazards
• Electrical hazards
• Skin contact with hazardous substances
• Noise
• Manual tasks
• Radiation
• Environmental hazards
• Hazards outside the confined space

A risk assessment is mandatory for confined spaces under the WHS Regulations. The PCBU must ensure that a competent person conducts a risk assessment and is recorded in writing. A risk assessment will determine the measures that should be implemented to control risks. It will help to:  

• dentify which workers are at risk of exposure
• Determine what sources and processes are causing that risk
• Identify if and what kind of control measures should be implemented
• Check the effectiveness of existing control measures.

A competent person must review and revise the risk assessment whenever any risks change.

A copy must be kept until at least 28 days after the work it relates to is completed, or if a notifiable incident occurs in connection with the work to which the assessment relates, for at least two years after the incident occurs.

A copy of the risk assessment must be available to any relevant worker on request.

Further guidance on the risk management process and the hierarchy of control measures is available in the How to manage work health and safety risks: Code of practice.

A confined space entry permit may be used as a risk assessment record.

Atmospheric testing and monitoring

Testing and monitoring the atmosphere in a confined space are routine parts of determining appropriate control measures for confined spaces.

Air monitoring in a confined space should be carried out by a competent person using a suitable, correctly calibrated gas detector.

You must ensure that while work is being carried out in a confined space to test the atmosphere for:

• oxygen content
• airborne concentration of flammable contaminants
• airborne concentration of potentially harmful contaminants (for example, hydrogen sulphide and carbon monoxide).

Look at the assessed risks and decide what needs to be done to eliminate or reduce the risks and how quickly these control measures need to be implemented. The hierarchy of control guides you to choose a solution that most effectively eliminates or minimises the risk. There are different types of control strategies to eliminate or reduce the risks. These are listed below in order of their effectiveness.

Eliminate the risks

You must always aim to eliminate the risk. Therefore, the first question is: can the work be carried out without entering a confined space?

Work could be carried out from outside the confined space, for example, by:

• installing fixed or temporary cleaning devices, for example, spray balls using high-pressure hoses inserted through an access hatch to clean the inside of a tank
• using remote cameras or a mirror attached to a probe for internal inspection of vessels
• using remotely operated rotating flail devices, vibrators or air purgers to clear blockages in silos
• using a hook, long-handled clasp or magnet on a string to retrieve an object dropped into a confined space.  

If entering a confined space cannot be avoided, then a safe system for working inside the space must be implemented by one or more of the following:

Substitution 

Minimise the risk by substituting or replacing a hazard or hazardous work practice with something that gives rise to a lesser risk. For example, changing work methods to minimise time inside the confined space reduces the likelihood of heat stress.

Isolation 

Minimise the risk by isolating or separating the hazard or hazardous work practice from any person exposed to it, for example, by isolating moving or electric parts. All potentially hazardous plants and services should be isolated before any person entering the confined space. Refer to AS 2865:2009 Confined spaces for further information on isolation requirements.

Engineering controls 

Engineering controls are physical measures to minimise risk, such as forced extraction ventilation for large spaces, tanks, and vessels.

A safe atmosphere can be achieved within the confined space using cleaning, purging and ventilation methods.

Administrative controls 

If risk remains, it must be minimised by implementing administrative controls so far as is reasonably practicable. For example, providing training relevant to working in confined spaces.

Entry permits

A confined space entry permit provides a formal check to ensure all elements of a safe system of work are in place before people are allowed to enter the confined space. It also provides communication between site management, supervisors and those carrying out the work. It ensures that the PCBU has checked and authorised the entry to the confined space and it is safe to proceed.

A PCBU must not allow or direct a worker to enter a confined space to carry out work unless the worker has been issued a confined space entry permit.

A copy of the permit must be kept until the work is completed or, if a notifiable incident occurs, for at least two years after the confined space work to which the permit relates is completed.

Communication and safety monitoring

A communication system is needed to communicate between people inside and outside the confined space and to summon help in an emergency.

Depending on the conditions in the confined space, communication can be achieved by voice, radio, hand signals or other suitable methods.

Before a worker enters a confined space, a standby person must be assigned to continuously monitor the wellbeing of those inside the space, if practicable, observe the work being carried out, and initiate appropriate emergency procedures when necessary. The standby person should:

• understand the nature of the hazards inside the confined space and be able to recognise signs and symptoms that workers in the confined space may experience
• remain outside the confined space and do no other work which may interfere with their primary role of monitoring the workers inside the space
• have all required rescue equipment (for example, safety harnesses, lifting equipment, and a lifeline) immediately available
• have the authority to order workers to exit the space if any hazardous situation arises
• never enter the space to attempt a rescue.

Entry and exit procedures 

For the entire period for which the confined space entry permit is valid, procedures should be in place to indicate when any worker is in the space, for example, by using tags, a system of signing in and out on the entry permit or having a standby person record who is in the space.

Signs and barricades 

Before any work in a confined space starts, signs must be erected to prevent entry of persons not involved.

Signs must warn against entry by people other than those listed on the confined space entry permit and must be placed at each entrance to the confined space. Signs must be in place while the confined space is accessible, including when preparing to work in the space, during work in the space, and when packing up on completion.

Signposting alone should not be relied on to prevent unauthorised entry to a potential confined space. Security devices, for example, locks and fixed barriers, should be installed.

Personal protective clothing and equipment (PPE)

Any remaining risk must be minimised with suitable PPE. For example, respiratory protective equipment (RPE) when oxygen levels are outside the safe range.

Suppose it is not reasonably practicable to ensure the confined space contains a safe oxygen level or safe levels of airborne contaminants. In that case, appropriate air-supplied RPE must be provided. Further guidance is available in AS/NZS 1715:2009 selection, use and maintenance of respiratory protective equipment.

Control measures must be maintained to remain fit for purpose, suitable for the nature and duration of the work and be installed, set up and used correctly.

The control measures put in place should be regularly reviewed to make sure they are effective. If the control measure is not working effectively, it must be revised to ensure it effectively controls the risk. Common review methods include workplace inspection, consultation, testing and analysing records and data.

Emergency procedures

There must be documented first aid and rescue procedures to be followed in an emergency, and ensure that workers practise those procedures to ensure they are efficient and effective. In an emergency, first aid and rescue procedures must be initiated from outside the confined space.

The openings for entry and exit must be sufficient to allow emergency access, openings must not be obstructed, and any plant, equipment and personal protective equipment (PPE) provided for first aid or emergency rescue must be maintained in good working order.

First aid and rescue procedures should be rehearsed with workers to ensure they are effective.

Yes. A person must be on standby in the immediate vicinity outside the designated confined space.

Before work in a confined space begins, a competent person must carry out a risk assessment. The risk assessment must be in writing and take account of the hazards involved, work methods to be adopted, risk factors to be considered, and the control measures to be adopted. One risk factor to consider is the arrangement for emergency response procedures, including rescue, first aid and resuscitation. 

A rescue plan needs to be put in place that can be implemented in an emergency. All equipment required in an emergency (such as harnesses, respirators and stretchers) must be available and serviceable. The relevant emergency response team members required to use the equipment must be trained in its use. The rescue members shall be trained in rescue work, including first aid administration. The standby person may form part of an emergency response team by acting as the coordinator but must remain outside the confined space.

Safety harnesses and lines complying with AS/NZS 1891.1 should be worn where there is a risk of falling whilst descending into or ascending out of the designated confined space or where rescue by a direct horizontal or vertical route is possible.

The use of hand-operated lifting equipment should be considered, where appropriate, to facilitate the removal of an unconscious person from a confined space.

A confined space should never be purged with pure oxygen. Where necessary, the confined space should be cleared of contaminants using a suitable purging agent. Gas mixtures used for this purpose should not contain an oxygen content greater than 21%. Compressed clean air is economical and suitable for use.

Supplied-air respiratory protection devices should be worn when:

• Control measures cannot establish or maintain a safe atmosphere or 
• The work to be carried out within the confined space is likely to degrade/contaminate the atmosphere, e.g. hot work or painting.

Further guidance is available in AS/NZS 1715:2009 Selection, use and maintenance of respiratory protective equipment.