Epoxy Injection SWMS

Epoxy injection is a structural repair technique used to bond cracks in concrete elements such as slabs, beams, columns, retaining walls and post-tensioned decks. The process involves drilling injection ports, sealing crack faces with surface paste, then pumping a two-part epoxy resin under pressure (typically 7–20 bar) using manual or pneumatic injection equipment. The work generates exposure to hazardous chemicals (bisphenol-A diglycidyl ether, amine hardeners), pressurised fluid hazards, dust from drilling, and frequently occurs in confined or elevated positions on active construction sites. Under WHS Regulation 2025, a SWMS is mandatory because the task constitutes High Risk Construction Work — specifically the use and storage of hazardous chemicals on a construction project, with sensitisation, dermatitis and respiratory illness risks documented in Safe Work Australia's model code. The SWMS must be prepared before work commences, consulted with workers, kept accessible at the workplace, and reviewed if controls are revised or an incident occurs.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Where structural engineer permits, eliminate injection by specifying mechanical stitching or carbon-fibre overlay so no resin handling, pressure or amine exposure occurs on site.
2. 2Elimination — Pre-batch and pre-cartridge resin off-site in a controlled facility so workers never decant bulk Part A and Part B at the construction workplace.
3. 3Substitution — Specify low-viscosity, low-vapour-pressure modified epoxy systems with non-volatile cycloaliphatic amine hardeners in place of aromatic amine or solvent-thinned products.
4. 4Substitution — Replace hammer-drilled ports with surface-mounted adhesive injection nipples to remove respirable crystalline silica generation entirely from the task sequence.
5. 5Engineering — Use on-tool H-class HEPA dust extraction shrouds rated to AS/NZS 60335.2.69 on all drilling and provide local exhaust ventilation at the mixing station.
6. 6Engineering — Fit injection lines with pressure-relief valves, whip checks and burst-rated hoses certified to manufacturer maximum working pressure with quarterly hydrostatic test records.
7. 7Administrative — Issue and consult this SWMS at pre-start, restrict the exclusion zone to trained operators only, and limit continuous injection sessions to two hours with rotation.
8. 8Administrative — Maintain a hazardous chemicals register and current SDS per WHS Reg 2025 r344, conduct atmospheric monitoring and provide health surveillance for isocyanate/amine exposure.
9. 9PPE — Wear chemical-resistant nitrile gauntlets (0.38 mm minimum) over cotton liners, Tyvek 500 coveralls, ANSI Z87 indirect-vent chemical goggles and full face shield during injection.
10. 10PPE — Use P2 respirators for drilling and ABEK1-P2 cartridge respirators for mixing/decanting, fit-tested to AS/NZS 1715 with cartridge change-out schedule documented.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

On a multi-storey carpark refurbishment, a remedial concreting crew is scheduled to inject 140 lineal metres of shrinkage cracks in the suspended slab soffit from a scissor lift. At the 6:45 am pre-start brief, the supervisor opens this SWMS on a tablet and walks the three-person crew through each hazard line. The injection technician flags that yesterday's drilling generated more dust than expected because the slab aggregate was harder than specified — the supervisor consults the engineering controls section and upgrades from the standard shrouded SDS drill to an M-class extractor coupled with wet-edge misting, recording the variation on the SWMS amendment page and having all three workers re-sign the sign-on register. The crew confirms nitrile gauntlets, ABEK1-P2 respirators and face shields are on the lift before ascending. Mid-shift, a port blows off at approximately 14 bar, spraying resin onto a goggle lens. Because the SWMS exclusion-zone control had kept the labourer two metres clear, no skin contact occurred; the technician follows the SWMS emergency procedure, depressurises the pump, swaps the failed port, and the supervisor logs the near-miss against hazard line three. The SWMS is then reviewed at the next toolbox to determine whether port adhesive cure time should be extended from 20 to 30 minutes before pressurisation.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• AS 3600 — Concrete structures

Frequently asked questions