Bromadiolone is a pesticide that is registered for use around grain and industrial sheds for mice and rat control. As far as I am aware it has never been used for in crop control of mice. I have checked the relevant Act and bromadiolone did not appear to have a Maximum Residue Limit under the federal government Act.

All pesticides leave residues in grain and meats and we can now test down to parts per trillion, in some cases, so there is a maximum limit established for trade so all registered chemicals for use in crop and where animals must have a maximum residue limit (MRL) that allows for them to be traded and exported.

If there is no MRL, the limit is zero. If people use these chemicals and they are detected the product and potentially the farm livestock and grain is quarantined until the residue declines.In the 1990's a vet in the NSW ag department recommended during a drought that cotton trash, largely leaf and stem could be a useful supplement for feeding to cattle if it was blended with grain.

HAVE YOUR SAY: CLICK HERE TO SEND A LETTER TO THE EDITOR

Many graziers thought this was a great idea for cheap fodder that was just going to waste. Unfortunately the cotton had been sprayed with a chemical called Helix and cotton wasn't a grazing crop so no one bothered to apply for an MRL so the MRL was zero. The chemical was picked up during testing for chemical residues.

Thousands of cattle were unsaleable.

Farmers launched legal action against the department that only failed because the judge said the departments record keeping at the time was so poor they could not find the article. It did exist.

Therefore the correct question to ask to avoid widespread chemical contamination of farming and grazing land is; Has a Maximum Residue Limit been established or can it be established for the use of bromadiolone in crops and pasture for grazing animals.

Armidale