The latest Environmental Protection Authority report monitoring the aerial use of 1080 poison for pest control says operators are mostly following the rules, although more breaches were reported last year.
There were 49 aerial operations last year, covering more than 490,000 hectares.
Eleven breaches of controls from operator oversights or accidents were recorded, almost double the previous year.
Those were mainly due to baits being applied or spilled outside the permitted area.
The EPA attributed the higher number of breaches notified to improved reporting by aerial operators and monitoring by enforecment agencies.
A further 11 breaches were caused by vandalism and interference by the public, but that was down from 18 in 2010.
1080 is used to control rabbits, possums, rodents and mustelids, such as ferrets, stoats, and weasels.