Part 4.3: WHS Confined Spaces

Regulatory citation: Model Work Health and Safety Regulations, Part 4.3 (Regulations 62–77)

What Are the WHS Confined Space Regulations?

Part 4.3 of the model Work Health and Safety Regulations sets specific requirements for work in confined spaces. A confined space is generally an enclosed or partially enclosed space that is not designed or intended to be occupied by a person, is at or near atmospheric pressure while someone is in it, and is likely to present a risk from an unsafe oxygen level, contaminants such as airborne gases or vapors, or engulfment. Examples include tanks, silos, pits, sewers, some trenches and vessels.

Why These Regulations Matter

Confined space incidents often kill more than one person, because would-be rescuers enter without protection and are overcome too. Hazards like low oxygen or toxic gas are often invisible, so strict controls are essential.

Core Obligations

1. Manage the Risks and Avoid Entry Where Possible

PCBUs must manage risks associated with confined spaces, and the first question should always be whether the work can be done without anyone entering the space.

2. Entry Permits

A worker must not enter a confined space without a written confined space entry permit issued by a competent person. The permit records the space, the workers authorized to enter, the risk control measures and the work to be done.

3. Signage

Signs must be erected to warn people not to enter the confined space without a permit, both while work is being prepared and while it is carried out.

4. Communication and Standby Person

A system of communication must be in place between workers inside the space and people outside, and a standby person must continuously monitor the well-being of those inside and be ready to initiate emergency procedures.

5. Safe Atmosphere

PCBUs must ensure, so far as is reasonably practicable, that the space has a safe oxygen level (between 19.5% and 23.5% by volume under normal atmospheric pressure), that airborne contaminants are below their exposure standards, and that any flammable gas or vapor is below 5% of its lower explosive limit. Where this isn't possible, appropriate respiratory protection and other controls must be used.

6. Isolation of Plant and Services

Plant, services and connected pipes or ducts that could introduce hazards, such as material, gas or energy, must be isolated before entry.

7. Emergency Procedures and Rescue

First aid and rescue procedures must be established and practiced, and must not rely on unprotected people entering the space.

8. Training and Records

Workers involved in confined space work, including standby persons and permit issuers, must receive suitable information, training and instruction. Risk assessments and entry permits must be kept as records in line with the regulations.

Common Compliance Approaches

Confined Space Register

Identify and list all confined spaces at the workplace, mark them clearly and restrict access.

Pre-Entry Atmosphere Testing

Test the atmosphere with calibrated gas detectors before entry and continuously during work, testing from top to bottom where gases may layer.

Rescue Planning

Provide rescue equipment such as tripods and winches, and run rescue drills so the team can respond without putting more people at risk.

Example: Confined Space Work in Practice

A water utility needs to inspect the inside of a storage tank. First, it considers using a camera to avoid entry, but a physical repair is required. The competent person isolates inlet pipes, ventilates the tank, tests the atmosphere and issues an entry permit. A trained standby person stays at the entrance with a radio and a retrieval system attached to the entrant's harness, and gas levels are monitored continuously until the work is finished and the permit is closed out.

Note: This summary is based on the model WHS laws published by Safe Work Australia. Most states and territories have adopted them with minor variations, while Victoria has its own OHS laws. Always check the legislation and codes of practice that apply in your jurisdiction.

Frequently Asked Questions

What is a confined space under WHS law?

A confined space is generally an enclosed or partially enclosed space that isn't designed or intended for people to occupy, is at or near normal atmospheric pressure, and is likely to present a risk from unsafe oxygen levels, airborne contaminants, flammable atmospheres or engulfment. Tanks, silos, pits, sewers and vessels are common examples.

Do all confined space entries need a permit?

Under the model WHS Regulations, a worker must not enter a confined space unless a confined space entry permit has been issued for the work. The permit must be issued by a competent person and record the controls in place.

What is a safe oxygen level for confined space entry?

Under the model regulations, a safe oxygen level is between 19.5% and 23.5% by volume under normal atmospheric pressure. Levels outside that range can cause loss of consciousness or increase the risk of fire.