MELBOURNE Port terminal grain receiver Emerald Grain issued a safety alert last month after registering a significant increase in deliveries of grain from on-farm storages with unacceptably high levels of phosphine.

Phosphine is safe and effective to control pests of stored grain when applied correctly.  However incorrect use is illegal, is harmful to health and can lead to insect resistance and risk export markets.

The threshold level in a truckload of grain is 0.3 parts per million (ppm) phosphine, and any load reading higher when tested will be rejected.

The established procedure of employees at the receival site is to issue the vehicle driver with a rejection notice, a minimum elapse of time required before the load may be retested and authorities may be notified. Any parties involved with loading and transporting inappropriately fumigated grain may be prosecuted.

Incorrect use of phosphine has been an issue in other states.  Potential breaches are notified for risk assessment under the Chemical Usage (Agricultural and Veterinary) Control Act 1988.