Biosecurity Queensland Senior Scientist Mary O'Brien said spray drift had the potential to cause damage to or contaminate off-target crops, livestock and sensitive areas including houses, schools, waterways and riparian vegetation.

"Off-target movement of agricultural chemicals is costly to producers with particular crops being extremely sensitive to spray drift," Ms O'Brien said.

"Broadleaf crops such as grapevines, cotton, sunflowers and pulses are extremely sensitive to spray drift from a range of broadleaf herbicides.

"Preventing any type of off-target movement should be a major consideration for all chemical users and chemical label instructions should be strictly followed.

"The use of agricultural chemicals is carefully regulated to minimise potential risks to not only crops, but to human health, the environment and trade and to ensure the long-term sustainability of our primary industries."

Ms O'Brien said the risk of spray drift occurring increased if spraying was done at night or when inappropriate equipment was used.

"Night spraying is strongly discouraged as it is difficult to accurately assess weather conditions," she said.

"To reduce the chances of spray drift occurring, spraying should only be done when weather conditions are suitable. It is also good practice to notify neighbours of proposed spraying.

"It is important to remain vigilant when using agricultural chemicals to protect surrounding crops and livestock and to also ensure the ongoing availability of these chemicals."

Anyone misusing agricultural chemicals may be fined up to $60,000.