Hexavalent Chromium Plating & Spraying SWMS

Hexavalent chromium [Cr(VI)] electroplating and thermal spraying operations expose workers to one of the most potent occupational carcinogens recognised in Australian workplaces. Classified by IARC as a Group 1 human carcinogen with confirmed causation of lung cancer, sinonasal cancer and severe respiratory sensitisation, Cr(VI) is regulated under WHS Regulation 2025 Chapter 7 (Hazardous Chemicals) with a workplace exposure standard TWA of 0.05 mg/m³ — a level routinely exceeded near uncontrolled plating tanks and HVOF spray booths. A Safe Work Method Statement is mandatory wherever Cr(VI) is handled because the work constitutes hazardous chemical use under Regulation 347, triggers health monitoring duties under Regulation 368 (Schedule 14), and demands documented engineering controls, RPE selection and decontamination procedures. This SWMS integrates plating tank LEV verification, thermal spray booth capture, biological monitoring schedules and hazardous waste treatment pathways into a single auditable workflow for PCBUs, supervisors and operators.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Substitute hard chrome plating with HVOF tungsten carbide or laser cladding where engineering specification permits, eliminating Cr(VI) from the process entirely.
2. 2Elimination — Decommission obsolete decorative chrome lines and transition to trivalent chromium Cr(III) chemistry which is not classified as a Group 1 carcinogen.
3. 3Substitution — Replace hexavalent chromium passivation with trivalent chromium conversion coatings on zinc-plated parts, reducing WES exposure risk by orders of magnitude.
4. 4Substitution — Use pre-mixed Cr(VI) salt solutions instead of solid chromic acid flake to eliminate dust generation during tank make-up and replenishment.
5. 5Engineering — Install push-pull or slot-hood LEV on every plating tank designed to AS 1668.2 with minimum 2.5 m/s capture velocity and quarterly airflow verification.
6. 6Engineering — Operate thermal spray booths under negative pressure with HEPA-filtered exhaust, interlocked booth doors and continuous differential pressure monitoring with alarm.
7. 7Administrative — Conduct atmospheric monitoring every six months and biological urinary chromium monitoring per AS 2865 with results reviewed by an appointed registered medical practitioner.
8. 8Administrative — Implement strict change rooms with clean/dirty zone separation, on-site laundering of contaminated PPE, and prohibition on wearing work clothing off-site.
9. 9PPE — Issue supplied-air respirators (AS/NZS 1715/1716) with minimum protection factor 50 for tank-side work and PAPR full-face for spray booth operations.
10. 10PPE — Provide chemical-resistant PVC gauntlets, chrome-acid splash aprons, full-face shields and impervious boots, replaced on any sign of degradation or contamination.

Applicable Codes of Practice

Worked example

At a regional aerospace component refurbishment facility, the morning shift supervisor opens the Hexavalent Chromium Plating & Spraying SWMS at the pre-start toolbox for a landing-gear strut rechroming job. Three plating operators sign on after walking through the hazard register — particular attention is paid to the LEV airflow log, which shows the eastern tank slot velocity dropped to 2.1 m/s during yesterday's servicing. The supervisor selects the engineering control row, marks the tank out of service, and reassigns the strut to the western line where airflow verified at 2.7 m/s that morning. Operators don supplied-air respirators per the PPE control, with the airline pressure cross-checked against the SWMS sign-on sheet. Mid-shift, an operator notices a small tear in his PVC gauntlet during anode adjustment; he steps out to the change room, follows the decontamination sequence documented in the SWMS, replaces the glove, and the supervisor signs the deviation in the live-amendment column. Before knock-off, urinary chromium sample tubes are collected per the biological monitoring schedule referenced in the SWMS and dispatched to the appointed registered medical practitioner. The document is countersigned, filed in the exposure register, and retained for the 30-year period required under WHS Reg 368.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Managing Risks of Hazardous Chemicals CoP; Safe Work Australia hexavalent chromium WEL

Frequently asked questions