Operating Theatre Clinical Safety SWMS

Operating theatre clinical staff face a convergence of chemical, biological, radiation and ergonomic hazards that are largely invisible to the patient-focused workflow. Scavenged and fugitive anaesthetic gases (nitrous oxide, sevoflurane, desflurane) accumulate during induction, mask leaks and circuit disconnects; surgical plume from electrosurgery and laser ablation contains viable virions, carcinogenic aldehydes and ultrafine particulates; image-intensifier C-arms deliver scatter radiation to gowned staff; and patient transfers between trolley and table generate cumulative musculoskeletal load. Under the model WHS Regulations Part 7.1 a PCBU must manage airborne contaminants below workplace exposure standards, and clauses 38–39 require a documented risk assessment with controls. Because the work involves hazardous chemicals and identified biological hazards, a SWMS is mandatory before the procedure list commences and must be accessible at the theatre control desk.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — Replace open-circuit mask induction with intravenous induction where clinically appropriate, eliminating fugitive volatile anaesthetic release at the patient airway interface entirely.
2. 2Elimination — Remove hand-to-hand sharps passing by mandating a neutral hands-free transfer zone (kidney dish or magnetic mat) for all scalpels and suture needles.
3. 3Substitution — Substitute high-vapour-pressure desflurane with sevoflurane or total intravenous anaesthesia for long cases to reduce theatre atmospheric loading and greenhouse footprint.
4. 4Substitution — Use pre-mixed bone cement cartridge systems in lieu of open bowl mixing to substitute closed-vapour delivery for open monomer evaporation.
5. 5Engineering — Verify AS/NZS 1668.2 theatre HVAC delivers minimum 20 air changes per hour with active anaesthetic gas scavenging at 30 L/min flow and quarterly atmospheric monitoring.
6. 6Engineering — Operate dedicated surgical smoke evacuator with ULPA filtration within 5 cm of the electrosurgical tip for every diathermy and laser activation, replacing filters per manufacturer cycle count.
7. 7Engineering — Position lead-equivalent mobile shields and ceiling-suspended acrylic screens between C-arm scatter source and staff, with personal dosimeters issued per ARPANSA RPS 14.1.
8. 8Administrative — Conduct documented pre-list theatre brief covering this SWMS, laser/radiation safety officer nomination, sharps count protocol and confirmation of scavenging system function before first patient entry.
9. 9Administrative — Restrict pregnant or declared workers from rooms with active anaesthetic exposure exceeding action level until atmospheric monitoring confirms compliance with the workplace exposure standard.
10. 10PPE — Issue N95 respirators for plume-generating cases, laser-specific wavelength-rated eyewear (CO2 10,600 nm or Nd:YAG 1064 nm), lead aprons with thyroid shields and double-gloving with indicator system for sharps work.

Applicable Codes of Practice

Worked example

At a metropolitan private hospital's orthopaedic list, the theatre coordinator opens the morning brief at 0715 by tabling this SWMS alongside the procedure schedule. The first case is a primary total hip replacement requiring bone cement and intra-operative imaging. Working through the hazard register, the coordinator confirms the C-arm radiographer has dosimeters, identifies the cementing nurse, and verifies the plume evacuator filter cycle count against the device log. The anaesthetic technician reports the scavenging vacuum gauge reading is below specification, so the case is held until biomedical engineering restores flow — a control escalation the SWMS explicitly authorises any team member to call. All staff initial the sign-on sheet acknowledging laser-not-in-use status, sharps neutral-zone protocol and lead apron allocation. Midway through cementing, the circulating nurse observes that the bowl mixing system is being used instead of the cartridge substitution control specified — she invokes the SWMS stop-work clause, the team switches to the cartridge stock, and the deviation is recorded as a corrective action against the document. At case close, the sharps count reconciles, the dosimeter readings are logged, and the SWMS is annotated with the substitution-control variance for review at the next clinical governance meeting, demonstrating the document functioning as a live operational control rather than a filed compliance artefact.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Code of Practice — Hazardous Manual Tasks

Frequently asked questions