Confined Space Welding SWMS
Arc (MMAW) and MIG (GMAW) welding inside tanks, vessels, pits, pipes, ducts or similar enclosed spaces meeting the AS 2865-2009 confined space definition. Covers dual confined-space + hot-work permits, atmospheric monitoring, mechanical ventilation, fume concentration controls, electric-shock controls in damp confined conditions, and rescue arrangements.
SWMS variants reference your state’s WHS legislation. Instant download after payment.
Confined space welding covers arc (MMAW) and MIG (GMAW) welding carried out inside a tank, vessel, pit, pipe, duct or similar enclosed space that meets the AS 2865-2009 confined space definition. It is a deliberately comprehensive document because two high-risk regimes apply at once: confined space entry under Part 4.3 of the Work Health and Safety Regulation 2025 (NSW) and AS 2865-2009, and hot work under AS 1674.1 and AS 1674.2. In an enclosed volume the hazards multiply rather than add — welding fume concentrates with nowhere to vent, shielding or fuel gas displaces oxygen, any leak enriches the atmosphere, electric-shock risk rises in damp conductive conditions, and egress is restricted.
Confined space welding is high risk construction work under Section 291 of the WHS Regulation 2025 (NSW) on two counts at least: it is work carried out in or near a confined space, and it is work in an area that may have a contaminated or flammable atmosphere. A SWMS must be prepared before the work commences (Section 299) and kept available at the workplace, and it must be given to the principal contractor if one is appointed. Critically, the SWMS complements but does not replace the confined space entry permit required under Part 4.3 — both are required and work together. Confined space entry has the highest fatality-per-entry ratio of any high-risk category, and more than half of confined space deaths are would-be rescuers; this document is written on the assumption that the atmosphere is hostile until tested, egress is restricted, and self-rescue is not guaranteed.
Hazards identified
12 hazards covered, sorted by priority.
Rapid loss of consciousness and asphyxiation where oxygen falls below 19.5%
Violent combustion of clothing and flash fire where oxygen rises above 23.5%
Flash fire or explosion ignited by the arc, with fatal blast and burn injuries
Lung cancer and manganism, with no dilution of fume in the confined volume
Toxic gas accumulation and asphyxiation in the enclosed space
Electrocution, at markedly elevated risk compared with open-area welding
Severe burns and ignition of the space with limited means of egress
Delayed escape and entrapment if conditions deteriorate during the work
Multiple-fatality outcome where rescue is attempted without equipment and training
Burns, drowning or crush injury from un-isolated mechanical, fluid or pressure energy
Emergency undetected, or the standby person entering in breach of the plan
Heat exhaustion, heat stroke and loss of judgement before loss of consciousness
Control measures
Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.
- 1Eliminate the entry where reasonably practicable — weld outside the space, prefabricate, or use remote or automated methods.
- 2Two permits before entry: a confined space entry permit (Section 67) and a hot-work permit. The SWMS does not replace the entry permit.
- 3Test the atmosphere before entry and monitor continuously during welding with a calibrated four-gas detector (oxygen, LEL, carbon monoxide and process gases); evacuate below 19.5% or above 23.5% oxygen, at 5% of the LEL, or on a 5% change in any gas.
- 4Forced mechanical ventilation throughout the work, with the intake in clean air; never use oxygen to ventilate or freshen the space.
- 5Keep fuel-gas and shielding-gas cylinders outside the space, leak-check the lines, and remove torches, electrode holders and the MIG gun from the space during any break so a leak cannot accumulate.
- 6Local exhaust or on-tool fume extraction at the arc, and supplied-air respiratory protection (airline or self-contained breathing apparatus); air-purifying respirators are not acceptable for confined space welding.
- 7A voltage-reduction device and extra-low-voltage lighting to AS 1674.2, with dry insulation between the welder and the work.
- 8Isolate and lock out all connected plant, services and stored energy, with double-block-and-bleed on pressurised lines, verified before entry.
- 9A dedicated standby person stationed outside the entrance for the full duration, maintaining continuous communication and monitoring, who does not enter to attempt a rescue without supplied air, a harness and a second standby person.
- 10A documented and rehearsed non-entry rescue system: a tripod, winch and full-body harness to AS/NZS 1891.1, with a trained rescue team and emergency-services notification where extraction exceeds site capability.
- 11Heat-stress management: ventilation and cooling, work-rest cycles, hydration, and withdrawal at the first signs of heat illness regardless of work progress.
- 12Competency verified at permit issue: confined space entry training (for example RIIWHS202E), the welding trade qualification, and current gas-detector training.
- 13All workers must hold a valid White Card (General Construction Induction Training, CPCCWHS1001) before entering any construction workplace in Australia.
- 14Conduct a daily pre-start toolbox talk covering the day's work scope, identified hazards, required PPE, emergency procedures, and any changes since the previous shift. Record attendance and topics in the SWMS consultation section.
- 15PPE baseline for all workers: safety eyewear compliant with AS/NZS 1337.1, Class I or Class II safety footwear with protective toecap per AS/NZS 2210.3, high-visibility clothing where required by site rules, and task-specific RPE, hearing protection, and gloves as identified in the hazard register.
- 16Display the emergency plan at the work area showing first aid kit location, emergency contacts (000, site emergency number, nearest hospital with address), evacuation routes, and assembly point. Review with all workers at pre-start.
- 17Consult workers on WHS matters affecting them per Section 47 of the WHS Act 2011 (NSW), record the consultation, and obtain the HSR's acknowledgement where one has been elected.
- 18Review and update this SWMS whenever the work scope changes, after any incident or near miss, when a worker or HSR raises a WHS concern, when new hazards are identified, or at minimum every 12 months.
Applicable Codes of Practice
The primary technical standard for safe entry and work, including the 19.5% to 23.5% oxygen range, the standby person and the rescue arrangements.
Hot-work fire and explosion precautions for welding carried out inside the space.
Electric-shock protection and reduced-voltage measures for confined and electrically hazardous welding.
Risk assessment, entry permit, atmospheric testing, ventilation, standby person and rescue requirements for every confined space entry.
Fume control and the workplace exposure standard for welding fumes, which is far harder to meet in an enclosed volume and drives the use of supplied air.
Selection, use and maintenance of supplied-air and self-contained breathing apparatus for confined space atmospheres.
The full-body harness and connection points for non-entry rescue from vertical confined spaces.
High-Risk Construction Work triggered
Welding inside a tank, vessel, pit, pipe or similar space that meets the AS 2865-2009 confined space definition is, by itself, one of the 18 categories of high risk construction work in Section 291. A SWMS is mandatory for every entry, in addition to a confined space entry permit.
Welding consumes oxygen and generates fume, carbon monoxide, oxides of nitrogen and ozone in the enclosed volume, and shielding or fuel gas can accumulate to displace oxygen or create a flammable atmosphere — a contaminated or flammable atmosphere within the meaning of Section 291.
Confined space welding is high risk construction work under Section 291 of the WHS Regulation 2025 (NSW), so a SWMS must be prepared before the work commences (Section 299), kept readily accessible at the workplace, reviewed as necessary (Section 302), and given to the principal contractor if one is appointed. The work also involves energised electrical services (the welding circuit and any plant) and, for elevated or vertical entries, a risk of a fall of more than 2 metres. The SWMS does not replace the confined space entry permit required under Part 4.3 (Sections 62-77) — both are required. Confined space fatalities, more than half of which are would-be rescuers, are routinely prosecuted as Category 1 or Category 2 offences under the WHS Act where atmospheric-monitoring, ventilation or rescue controls were absent, with the most serious breaches carrying imprisonment for individuals.
Who this is for
- →Welders and boilermakers performing arc (MMAW) or MIG (GMAW) welding inside tanks, vessels, pits, pipes and other confined spaces.
- →Mechanical, fabrication and maintenance contractors carrying out in-situ welding repairs to plant and vessels.
- →Water, wastewater and process operators welding inside wet wells, digesters and process vessels.
- →Confined space stand-by and rescue providers supporting hot work inside a confined space.
- →PCBU safety managers and HSE advisors authorising combined confined space entry and hot-work permits.
What you receive
- ✓Editable Microsoft Word document (.docx) fully compatible with Microsoft Word 2016 and newer, Google Docs, and LibreOffice Writer.
- ✓Title page with editable fields for PCBU name, ABN, site address, project name, principal contractor details, and document revision date.
- ✓Hazard register with the 12 confined-space-welding hazards — each with a documented consequence, inherent risk rating on a 5x5 likelihood-consequence matrix, hierarchy-of-control measures, and residual risk rating.
- ✓Dual-permit prompts for a confined space entry permit and a hot-work permit, with a pre-entry atmospheric test record covering oxygen, LEL, carbon monoxide and process gases.
- ✓Rescue plan template with the non-entry retrieval equipment list (tripod, winch, harness), rescue team contacts, and emergency-services notification.
- ✓Supplied-air respiratory protection and standby-person prompts, and a competency verification table for the welder, standby person and permit issuer.
- ✓Worker consultation record per WHS Act s.47 and a worker sign-on register (blank, expandable).
- ✓Applicable legislation and Codes of Practice schedule pre-populated for NSW with a state-variance reference table covering VIC (OHS Act 2004), QLD, SA, WA, TAS, NT, and ACT.
- ✓Emergency procedure template and a revision log.
Worked example
A fabrication contractor is engaged to weld a repair patch inside a 3-metre-diameter carbon-steel process tank during a plant shutdown in Newcastle, NSW. The tank has a single 600 mm side manway and a residual product film, so the work is confined space welding — confined space entry plus hot work at once. Before entry the supervisor issues two permits: a confined space entry permit and a hot-work permit. The tank is isolated and locked out, the residual product is cleaned and the space is purged, and forced ventilation is run with the intake in clean air. A four-gas detector tests the atmosphere at the manway and at depth — oxygen 20.8%, LEL 0%, carbon monoxide 0 ppm — and is carried for continuous monitoring during the weld. The shielding-gas cylinder stays outside the tank with the lines leak-checked, the welder uses on-tool fume extraction and an airline-supplied respirator, and the welding set runs through a voltage-reduction device with extra-low-voltage lighting. A dedicated standby person remains at the manway with a tripod, winch and the welder's harness rigged for non-entry rescue, maintaining radio contact every five minutes. The MIG gun is removed from the tank during each break. The crew signs on to the SWMS at pre-start, the permits and atmospheric records are retained, and the entry permit is cancelled on completion.
Related legislation
- Work Health and Safety Act 2011 (NSW) — Section 19 primary duty of care; Section 47 consultation with workers; Section 31 Category 1 reckless-conduct offence; Sections 35-38 notifiable incidents.
- Work Health and Safety Regulation 2025 (NSW) — Section 291 (the 18 categories of high risk construction work, including work in or near a confined space and work in a contaminated or flammable atmosphere), Section 299 (preparation and content of a SWMS), Section 302 (review of a SWMS).
- Work Health and Safety Regulation 2025 (NSW) — Part 4.3 (Confined Spaces, Sections 62-77): entry permit (Section 67), communication and safety monitoring (Section 69), atmosphere (Section 71), flammable gases and vapours (Section 72), fire and explosion (Section 73), emergency procedures (Section 74).
- AS 2865-2009 Confined spaces; AS 1674.1-1997 and AS 1674.2-2007 Safety in welding and allied processes.
- Welding fumes (not otherwise classified) workplace exposure standard of 1 mg/m3 (8-hour time-weighted average, inhalable), in force from 18 January 2024; individual components including manganese have their own lower standards, with the manganese standard reducing to 0.1 mg/m3 from December 2026.
Frequently asked questions
What makes welding inside a confined space different from ordinary welding?
Two high-risk regimes apply at once and the hazards multiply rather than add. Welding fume concentrates in the enclosed volume with nowhere to vent; shielding or fuel gas displaces oxygen; any leak can enrich the atmosphere and turn a spark into a flash fire; electric-shock risk rises in the damp, conductive, body-against-the-work conditions inside the space; and egress is restricted. That is why this document is far more comprehensive than a general welding SWMS, with dedicated permit, atmospheric-monitoring, ventilation, supplied-air and rescue controls.
Does this SWMS replace the confined space entry permit?
No. Confined space welding requires both a confined space entry permit (under Section 67 of the WHS Regulation 2025) and a hot-work permit, and the SWMS complements but does not replace either. The SWMS sets out the generic hazards, controls and competencies; the entry permit authorises a specific entry on a specific day under those controls.
What respiratory protection is required for confined space welding?
Supplied-air respiratory protection — an airline-supplied respirator or self-contained breathing apparatus. Air-purifying respirators (including P3) are not acceptable for confined space atmospheres, which may be oxygen-deficient or contain contaminants beyond an air-purifying respirator's limits. Local exhaust or on-tool fume extraction is used as the primary fume control, with supplied air for the entrant.
Why is a voltage-reduction device needed inside a confined space?
Welding inside a confined space is done in damp, conductive conditions with the welder's body often against the work, which markedly increases electric-shock risk. AS 1674.2 requires reduced-voltage measures such as a voltage-reduction device for confined and electrically hazardous welding, alongside extra-low-voltage lighting and dry insulation between the welder and the work.
Is confined space welding high risk construction work in every state?
Yes. Work in or near a confined space is a high-risk construction work category in every Australian WHS jurisdiction, so a SWMS is mandatory before the work commences. In NSW it falls under Section 291 of the WHS Regulation 2025; Victoria applies the equivalent provisions under the Occupational Health and Safety Regulations 2017. The included state-variance table maps the citations for each jurisdiction.