Aside from the glyphosate levels in barley samples, Mr Reichstein said there were four MRL violations in WA last year – a canola sample with an imidacloprid reading of 0.086 milligrams per kilogram (Australian MRL of 0.05mg/kg), a second canola sample with haloxyfop 0.63mg/kg (MRL of 0.1mg/kg), an oat sample with a 0.12mg/kg glyphosate reading (MRL of 0.1mg/kg) and a lupin sample with a 0.083mg/kg of flutriafol (no MRL set).

“Some might say that out of 2000 samples, only four incidences is an excellent track record, but there are others that will say four is still too high,” he said.

“However, if you compare some of these results with the MRLs set by our markets, it would appear only 50pc of those samples with residues would be compliant.

“It is a highly risky situation if exporters are not fully aware of the trading requirements for that market.”

Mr Reichstein said non-compliance could become very expensive for the exporter, with cargo rejected or held at port, demurrage, disposal of contaminated grain, on-forwarding or return costs.

“The flow-on effect from a detection is increased sampling and cargo testing which impacts on all exporters and then the whole market can become restricted,” he said.

“Exporters may restrict future exports to avoid higher risks from increased testing and this can impact on the sale of Australian grain.”

Mr Reichstein outlined several cases of other MRL violations in Australia, including the 2014 case of a grower who created a imidazoline herbicide mix of imazapic and imazapyr rather than using the approved Intervix herbicide in a barley crop, which was detected in samples heading to Japan.

As a result, Japan increased its surveillance of Australian barley over the next five years.

“Japan has a high level of trust in Australian grain and while we were able to rectify the issue, we cannot afford to have markets lose confidence in Australia,” he said.

Flutriafol also remains an issue, with inadequate cleaning of trucks in between loads of fungicide-treated fertilisers and grain, leading to contamination, with one sample recording levels 254 times the limit of 0.02mg/kg.

“Since it was identified five years ago, the issue with flutriafol still hasn’t been resolved and we are still finding levels in samples,” Mr Reichstein said.

“Of the 21 samples last year that were more than the Australian MRL, we believe 50pc came from incorrect in-crop use and the other half from trucks or augers.”

Canola which has been treated with Verdict (haloxyfop) was still an issue, as Mr Reichstein said there were 17 violations of the 0.1mg/kg MRL set by the Australian Pesticides and Veterinary Medicines Authority (APVMA).

“After providing data to APVMA, the label was reviewed and the application timings were changed in 2014,” he said.

“But the old label is still out there and the product appears to be being applied too late in the season and contaminating the crop.

“Growers need to be aware of these issues and how they can affect market access overseas.”

It was also important for exporters to be aware of market MRL.

If countries want to change their MRL, an application is made to the World Trade Organisation through its Sanitary and Phytosanitary (SPS) notification system.

“As 80pc of Australia’s grain is exported, the NRS monitors this very closely in consultation with the grain industry and if a country notifies of a MRL change which might impact on our market access, a submission is prepared which seeks reconsideration of the change to ensure we retain on-going market access,” Mr Reichstein said.

“If we are very mindful of requirements from our markets and there is better communication between growers and handler and marketer on the application of chemicals, we can lower the risk and prevent violations in overseas markets.”