Boom Spray / Crop Spraying SWMS

Boom spray and broadacre crop spraying operations expose operators, ground crew and bystanders to acute and chronic chemical risk through mixing concentrated agrochemicals, calibrating nozzles under pressure, and applying schedule 5, 6 and 7 products across paddocks where wind, terrain and fatigue all shift hazard levels hour by hour. Under WHS Regulation 2011 (and the harmonised state instruments) a Person Conducting a Business or Undertaking has a non-delegable duty to identify chemical, plant and environmental hazards, consult with workers, and document control measures before work commences. A Safe Work Method Statement is mandatory whenever the activity involves hazardous chemicals at quantities triggering the Hazardous Chemicals Register, work near energised overhead lines, or use of mobile plant on uneven ground. This SWMS template provides a CIH-reviewed, editable framework covering mixing, calibration and boom application, aligned to AS/NZS 2210 footwear, AS/NZS 1715/1716 respiratory protection, and the APVMA-endorsed product label as the primary legal instruction.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Eliminate manual decanting by specifying closed-transfer systems (CTS) or returnable shuttles for all schedule 6 and 7 products under AS 2507.
2. 2Elimination — Eliminate spray-window pressure by scheduling applications outside critical neighbour-sensitive periods and removing energised overhead spans from the spray block where feasible.
3. 3Substitution — Substitute high-volatility ester formulations with amine or low-volatile salts during temperature inversion risk periods per APVMA spray-drift guidance.
4. 4Substitution — Substitute conventional flat-fan nozzles with air-induction low-drift nozzles rated by the Spray Drift Reduction Technology register to reduce driftable fines.
5. 5Engineering — Engineer cabin protection using a Category 4 pressurised filtered cab compliant with EN 15695-1, with charcoal filter change logged per AS/NZS 1715.
6. 6Engineering — Engineer bund containment around the chemical mixing pad with sealed concrete, eyewash and emergency shower meeting AS 4775 within 10 seconds travel.
7. 7Administrative — Administrative — Verify Delta-T, wind speed 3-15 km/h and inversion conditions using calibrated weather meter and record on spray diary per state Control of Use legislation.
8. 8Administrative — Administrative — Implement fatigue management with maximum 12-hour shift, mandated 30-minute breaks and two-way radio check-ins every 90 minutes during solo paddock work.
9. 9PPE — Issue chemical-resistant nitrile gauntlets, AS/NZS 1336 indirect-vent goggles and AS/NZS 1716 A1P2 respirator for all mixing and loading tasks per product label.
10. 10PPE — Provide coated Type 4 chemical coveralls to EN 14605, AS/NZS 2210.3 chemical-resistant boots, and dedicated laundering separate from domestic clothing.

Applicable Codes of Practice

Worked example

At a 2,400-hectare winter cropping enterprise, a spray supervisor convenes the pre-start brief at 4:30am beside the chemical shed before a glyphosate plus paraquat double-knock application. Using this SWMS as the working document, the supervisor walks the two operators through the hazard register, flagging that paraquat is schedule 7 and triggering the closed-transfer mixing control rather than the previous jug-and-funnel method. The Delta-T meter reads 4.2 with a 6 km/h southerly, inside the label envelope, so the team signs the weather observation panel of the SWMS. One operator raises that the eastern boundary paddock has an 11kV overhead span — the supervisor cross-references the powerline control row, marks the headland as a boom-down zone on the paddock map attached to the SWMS, and both operators initial the amendment. Mid-morning, wind shifts to 18 km/h gusting. The lead operator stops the rig, radios in, and the team formally suspends work using the dynamic-review section of the SWMS, recording time, weather data and resumption conditions. When spraying resumes at 3pm under improved conditions, the SWMS amendment is re-signed. The completed document is filed to the chemical use diary that evening, satisfying both WHS record-keeping and state Control of Use Act traceability.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Managing the Risks of Plant in Rural Workplaces CoP; AS 2789 — Quad bikes

Frequently asked questions