There have been a few cases of Australian grain being contaminated with chemicals after harvest. The chemical ended up on the grain through using the same trucks to move treated fertiliser and transport grain.
About 15% of Australian cereal crops use fungicide treated fertilizer. The fungicide flutriafol controls certain fungal diseases in canola, wheat and barley. Blending this fungicide with fertiliser can make it easier to apply. Using treated fertilisers appropriately is not a problem. Contaminated grain usually comes in contact with the fungicide after harvest.
Chemicals in foods – MRLs
Governments regulate the amounts of agricultural chemicals allowed to be in foods. For pesticides these are Maximum Residue Limits (MRLs).
MRLs are set as low as is practicable, to limit people’s exposures through food. They are usually well below a single toxic dose level. They ensure a person who eats the food in normal dietary patterns over a lifetime won’t go over the Acceptable Daily Intake (ADI). The ADIs are levels that should not cause adverse health effects.
MRLs for pesticides are set on the basis of Good Agricultural Practice (GAP). Using pesticides according to regulations and label instructions will not exceed food MRLs.
What’s the problem?
Australian grains are tested for pesticide residues, even if they stay in the country. Most Australian grains test below the maximum residue limits (MRLs). Fungicide residues on grain have exceeded the MRL of importing countries in a few cases. This can:
- incur penalties on all Australian grain going to that country
- tarnish Australian grain’s reputation as clean and high quality.
How to keep grain clean
Dedicated transport and storage for treated fertilizer is ideal. The next best step is hygiene. It’s not just trucks. All grain handling and storage equipment needs to be clean.
Clean equipment between loads of different products:
- Sweep or blow with compressed air to remove visible dust.
- Wash with a pressure hose and truck wash.
Sweeping alone won’t remove enough residue to protect grain.
Detailed instructions are in the Australian Grain Industry’s code of practice. Technical guideline no. 18 covers the truck cleaning procedure to use after transporting treated fertiliser.
Truck cleaning procedure (Grain Trade Australia)