Avoiding chemical residues in pulse grain

Posted in PulseCheck–Coastal on Mar 26, 2020

Avoiding chemical residues in pulse grain

Protecting Australia’s export markets and our reputation as a source of high quality, food-safe grain products relies on growers doing the right thing when applying agricultural chemicals. Failure to do so will potentially have high financial ramifications for growers, exporters and the broader grains industry.

All efforts must be taken to avoid unacceptable levels of crop protection chemical residues in food. Australia has in place a rigorous system that enables the safe use of a range of crop protection products that preserve yield and grain quality, while also avoiding the risk of residues of these products remaining in the grain at harvest.

The first stage is establishing chemical use patterns that are effective on the target pest, weed or disease in a particular crop. These use patterns form the basis of chemical registrations through the regulatory body, the Australian Pesticide and Veterinarian Medicine Authority (APVMA). Farmers must follow the label directions exactly for every chemical application.

The following expert advice is provided by GRDC's Manager Chemical Regulation, Gordon Cumming.

Maximum residue limits

As part of the registration process, the registering chemical company must provide data that shows the maximum residue limit (MRL), i.e the maximum amount of residue that can be expected in the grain at harvest when the correct use pattern is followed. If the MRL data shows that the expected residue amount would pose a health risk for consumers, then the product will not be registered for the proposed use pattern.

The 'health risk' is assessed based on the way the grain product is likely to be consumed. So, in Australia the amount of and the way chickpeas (for example) are consumed is different to how they are consumed in India (for example). Therefore, the Australian MRL may differ from the Indian MRL. Also, pulses are commonly eaten with very little processing or mixing with other foods. In many overseas countries the pulse grain is simply split and then boiled and eaten, often with few other ingredients, to form a meal.

Residue testing

In bulk grains such as cereals, and to a lesser extent, chickpeas, there is often significant co-mingling of grain prior to export. This means that a consignment of grain that might have higher detectable residue level is likely to be diluted by the other grain in the shipment. In commodities such as mungbeans, very little co-mingling occurs so each consignment must be below the MRLs. Vendor declarations (see below) are particularly important for crops like mungbeans.

Withholding periods

The registered use pattern is often quite specific about rates, timing and the number of applications permitted per crop. The label will also include a withholding period, i.e. the time that must elapse between when the product is applied and when the crop is harvested, cut for hay or grazed. All the specific instructions must be followed carefully.

The withholding period is based on scientific studies that have determined how long it takes for the crop plant to metabolise or breakdown the applied chemical to below the product's MRL.

Minor use and emergency use permits

Where a product is not registered in pulses, it must not be applied, unless a minor use or emergency use permit is in place. Australia is in an enviable position with our permit system, something that is not found in many other countries. Minor Use Permits (MUP) are only available for minor crops (such as pulses and oilseeds). They are issued in response to an ongoing agronomic problem where a full registration is not in place. Industry bodies, such as Pulse Australia, usually apply for the MUP on behalf of growers. Substantial data from around the world is assessed to determine if the proposed use pattern is effective and will not pose a health risk to consumers (similar to the process for full registration).

If an emergency situation occurs there is also an option for the industry to apply for an Emergency Use Permit (EUP). These permits are also issued based on data from Australian and overseas sources to support their safe use.

Once an MUP or EUP is issued it is a legally-binding adjunct to the product label. Minor use permits may be in place for a number of seasons, while emergency use permits are issued just for the period of the emergency, often only a few months. Once a permit has expired, it is no longer legal to apply that product unless full registration has been achieved.

Vendor declarations

At the end of the season growers are urged to complete a Vendor Declaration for grain harvested from each of their paddocks. This declaration shows what chemicals have been used on the crop and provides the information that marketers need when selling pulse grain into overseas markets.

These declarations must be filled out accurately and honestly, even if an error has been made. Alerting your marketer to any potential risk allows them to have the grain tested for residues and to find a market that is able to accept that product.

A product may be properly and legally applied to a crop in Australia, but if an importing country has a different (lower) MRL to the Australian MRL, the grain cannot be sold into that overseas market.

It is much better to find out about a problem before the grain leaves Australian ports as it is costly to the marketer and the grower if grain shipments have to be re-routed. If grain fails an MRL test in an overseas port, this also damages Australia's reputation as a supplier of clean grain and may have wide-ranging impacts on all Australian food exports.

Observe all witholding periods and record all product use on the GTA Grain Commodity Vendor Declaration, GTA SafeMeat Declaration Form and Commodity Declaration Form (mungbean), where applicable.

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