Termite Soil Injection / Pre-Construction SWMS

Termite soil injection and pre-construction chemical barrier treatment involves the bulk handling, dilution and pressure injection of Schedule 7 termiticides (typically bifenthrin, fipronil or imidacloprid concentrates) into perimeter trenches, sub-slab fill and penetrations before concrete pour. The work routinely occurs on active construction sites alongside other trades, with workers operating power drills through cured slabs, pressurised injection rods to 600 kPa, and handling concentrated organochlorine-replacement chemistries that pose acute dermal, inhalation and aquatic toxicity risks. Under WHS Regulation 2011 r291 the activity meets the definition of High Risk Construction Work because it involves use of Schedule 7 poisons and powered drilling into structural elements, mandating a Safe Work Method Statement be prepared, signed and held on site before work commences. The SWMS must be developed in consultation with affected workers, communicated at pre-start, and kept available for inspection by the regulator and principal contractor for the duration of the work.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Where possible specify a physical termite barrier system (stainless mesh or graded stone) under AS 3660.1 in lieu of chemical treatment, removing termiticide exposure entirely
2. 2Elimination — Sequence soil treatment before other trades mobilise to the slab area so no non-pest-control workers are present in the treatment exclusion zone
3. 3Substitution — Select the lowest-toxicity registered termiticide formulation (water-based suspension concentrate over emulsifiable concentrate) approved under APVMA registration for the target species
4. 4Substitution — Use pre-measured soluble sachets or closed-transfer couplers in place of open decanting of bulk concentrate from 20 L drums to mixing tank
5. 5Engineering — Operate closed-circuit injection rigs with anti-drip foot valves, pressure relief set at 700 kPa, and bunded mixing stations capable of 110% containment per AS 3780
6. 6Engineering — Conduct DBYD search, hydro-vac potholing and use of cable/pipe locator before any drilling penetration of slabs or natural ground exceeding 100 mm depth
7. 7Engineering — Capture concrete drill dust with H-class HEPA on-tool extraction or wet-cutting suppression to keep RCS below the 0.05 mg/m³ workplace exposure standard
8. 8Administrative — Pre-start SWMS sign-on, SDS toolbox review, exclusion zone signage and chemical register entry maintained per WHS Reg Chapter 7 hazardous chemicals duties
9. 9Administrative — Rotate operators on a 45-minute work / 15-minute shaded rest cycle when WBGT exceeds 28°C and provide 600 mL/hour cool electrolyte fluid
10. 10PPE — Chemical suit (Type 4/5 to AS/NZS 1336), nitrile gauntlets, full-face A1P2 respirator (AS/NZS 1716), chemical-resistant boots and impact-rated safety eyewear during all mixing and injection

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

On a 24-lot residential slab pour scheduled for Thursday, the pest control supervisor mobilises a two-person crew at 5:30 am to complete perimeter trench and sub-slab injection across Lots 7–10 before the concrete pumper arrives at 11:00 am. At the pre-start brief on the tailgate, the supervisor opens the Termite Soil Injection SWMS and walks both technicians through the hazard register, focusing on the day-specific risks: a forecast 34°C maximum (heat stress control activated), proximity of a live 240 V temporary builder's supply within 4 m of Lot 8 (DBYD plan reviewed, exclusion zone marked), and a fresh 200 L batch of bifenthrin SC requiring closed-coupler transfer. Each technician initials the sign-on sheet, confirms respirator fit-test currency, and dons Type 4/5 chemical suits before mixing commences. Midway through Lot 9, the operator notices the injection rig pressure spiking to 680 kPa as a rod encounters compacted fill. Referring back to the SWMS control for pressure-relief settings, he stops, depressurises the line, repositions the rod and resumes at 450 kPa rather than forcing the blockage. The deviation and corrective action are noted on the SWMS field amendment log, countersigned at smoko, and the document is returned to the site office for the principal contractor's records.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Managing Risks of Hazardous Chemicals CoP; APVMA registered product label requirements

Frequently asked questions