Responsible use of chemicals can reduce the risk of spray drift.

All agricultural chemicals can drift when sprayed. There are two types of spray drift:

• droplet drift - the airborne movement of liquid droplets away from the target intended to be sprayed
• vapour drift - the airborne movement of vaporised agricultural chemicals from the sprayed area.

Spray drift has the potential to cause injury or damage to plants, animals, environment or property, and can affect human health.

Chemical spraying is generally a safe practice when performed by responsible operators who follow manufacturers´ recommendations. However, undesirable spray drift can occur when chemicals are misused. This misuse is often due to operators failing to observe product label instructions. Label instructions serve a vital purpose, and by following them you increase the chance of the chemical reaching its target, reducing the potential of spray drift.

Please read labels carefully and make sure you fully understand all instructions before carrying out a spray operation. It is illegal to apply products contrary to label instructions.

Tips for preventing spray drift

Maintaining due care and attention at all times when spraying agricultural chemicals is as important as knowing how to apply the product correctly. These two factors go hand in hand to help to prevent or reduce spray drift. It´s called ´spraying it right´.

The following are some helpful tips for spraying it right:

• Maintain control of all spray operations. Stop spraying, or stop the contractor spraying if the conditions are not right.
• Read the agricultural chemical product label and follow the instructions accurately. Many products have specific spray drift management instructions dealing with optimal weather conditions and spray equipment.
• If you don´t understand a label instruction, ask someone who does before commencing the application. Product labels provide contact details of the manufacturer who can provide reliable technical advice to assist you if necessary.
• If you are not sure what you are doing consider engaging a professional contractor.
• Identify sensitive crops and areas, e.g. creeks and streams, livestock paddocks or schools around the area where you intend to spray, and let the spray operator know about these areas.
• Measure and record the weather conditions before and after the applications. If you think they have changed, stop and measure them during the application as well.
• Keep detailed records of each spray application. Good records will prove beneficial if complaints are made, particularly if you need to accurately recall information months after a spray event.
• Discuss your spray plans with your neighbours and contractors. Good communication can often avoid complaints from neighbours or prevent misunderstandings and unnecessary conflict.
• If possible, maintain a buffer zone between areas of application and areas where there is a risk of damage from spray drift.
• Select equipment (applicators and nozzles) that will give you the correct droplet size range to minimise drift and maximise efficiency. Smaller droplets are more likely to drift. Always use equipment as recommended by the manufacturer.
• Maintain the correct boom height for the nozzles being used. If spray is being applied aerially, make sure it is released only when the aircraft has levelled out above the crop and is turned off before ascending to turn.
• Calibrate the equipment correctly. Check with the manufacturer to find out how to correctly calibrate the equipment.
• Spray only in favourable weather conditions. Ideal wind speeds are between 3-15 km/h.
• During spraying, wind should be blowing steadily. Light and variable or gusty winds make it difficult to predict where spray will go.
• Spraying should not be carried out under calm or still conditions. Under calm conditions, droplets are more likely to remain suspended in the air.
• Ideally, wind should be blowing away from susceptible crops. If not, try leaving a buffer zone.
• Avoid spraying in temperatures near or above 30°C and when humidity is low as spray droplet size may be reduced, increasing the risk of spray drift.
• Do not spray when inversion conditions exist. Visual indicators include no wind, fog, dew, frost and smoke or dust hanging in the air or forming distinct layers. Inversion conditions are very prevalent in Australia.
• Keep your knowledge of application methods up-to-date. Attend equipment manufacturer or product manufacturer field days when these are organised in your area.

Further information

For detailed advice on spray drift reduction strategies, see:

• Managing spray drift fact sheet (Grains Research and Development Corporation website)
• Agricultural Chemical Users' Manual

For advice on dealing with potential spray drift in your local area, see:

• Dealing with spray drift