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Maximum residue limits: helping keep us safe

23 October 2019

news item

Market access is more important than ever. As other origins, such as the Black Sea, are increasing their production and improving their processes, it is critically important that we maintain market access and reputation for Australian grain. An essential aspect of this is meeting chemical maximum residue limits (MRLs) for Australia and our export markets.

Maximum residue limits can be traced back to shortly after World War II, when chemical regulation was introduced. As the use of pesticides in agricultural production increased, regulation was put in place to protect not only the end consumer, but the growers administering the pesticide, the supply chain and the environment.

After a period where countries were managing the regulation of chemicals and pesticides individually, it became necessary for a global approach.

International working parties were set up to consider pesticide use and associated issues, most importantly human health. They developed a framework of research, data analysis and eventually standards of pesticide tolerances.

As a result, an Acceptable Daily Intake (ADI) was established based on an acceptable intake level of a chemical that can be consumed without causing risk. These levels are scientifically reviewed back through the supply chain to the point where the chemical enters the system. This then leads to the establishment of tolerances which take into consideration the acceptable range and level of residues that can be present in or on an agricultural product at the first point of processing or consumption. These ADIs formed the basis of detailed studies to determine acceptable residue levels and the notion of a tolerance has evolved to what we know today as a maximum residue limit.

How does an MRL get approved?

Approval for an MRL starts with a chemical or pesticide being nominated for use on food or feed products. The chemical will have an appropriate ADI established. It is then assessed for how, when and where it will be used, how it will be metabolised by the grain crops, by animals in the case of feed stuffs and by humans.

National nutritional patterns and dietary intakes play an important role in this analysis of how the chemical will pass through the food chain.

At the production end, consideration is also given to ‘Good Agricultural Practice’ that is, what are the health implications to the grower and, is the chemical able to be managed well and applied at an effective rate to meet the required MRL.

All of this information is combined to establish an appropriate MRL, or maximum residue of a chemical that can be found in or on grain.

Who are MRLs designed to protect?

MRLs are established to protect people at numerous points through the supply chain from grower through to consumer, animals and the wider environment.

Growers are most often exposed to chemicals when applying it to their land or crops. An appropriate MRL, together with legislated label use instructions, work in conjunction with each other so that when the label is followed, the pesticide or chemical is administered safely to an approved crop or variety, at a correct rate, and the required withholding period is observed.

This correct use of the chemical is key to both maintaining safe access to a valuable production tool and meeting the required MRL.

Who works in this space in Australia?

In Australia, the Australian government statutory authority, Australian Pesticides and Veterinary Medicines Authority (APVMA) sets and maintains national MRLs for agricultural produce, including grain.

Food Standards Australia New Zealand (FSANZ) works closely with APVMA by assessing residues in food for safety, legitimacy and justification. FSANZ is also responsible for reviewing Australian MRLs and aligning them with international limits where possible.

FSANZ and APVMA also work closely with the standards issued by the international governing body Codex Alimentarius. While there is an international body, standards do differ between countries at times which can be due to factors native to that country such as pests and diseases, differing dietary patterns, cultural issues and food safety requirements.

Implications for import and export

A critical component of grain being accepted by the importing country is meeting their quality and regulatory requirements, and one key part of this is MRLs.

Glencore Agriculture Senior Commercial Manager, Lyndon Asser, says that while there are many internationally accepted MRLs, it is still common for countries’ limits to differ.

“MRLs are set within countries based on the country’s requirements, but also their familiarity, testing and research that the country has done,” Lyndon said.

“If a pesticide or the use of the chemical is relatively new, countries generally take time to become familiar with it and conduct testing before they establish an appropriate MRL.

“Right now we’re seeing a heightened emphasis on MRLs as end use customers become increasingly focused on food safety and quality.”

If a cargo is in breach of the importing country’s requirements, penalties can be severe, including an exporter or country being banned from shipping to the receiving country.

Bulk handling companies conduct a range of activities and processes to ensure continued access to these markets is maintained.

Viterra Chief Operations Officer, James Murray, says as a bulk storage and handling company, Viterra is focused on maintaining market access and reputation for South Australian grain.

“We have a number of processes in place which include declaration processes and testing of grain delivered into our system, at different times during harvest such as late in the season, or with certain chemicals applied,” James said.

“Declaration processes give us full oversight of grain delivered into our system so we can manage stocks and ensure grain meets requirements when it’s outturned.

“We have recently invested around $750,000 in new chemical residue equipment, which helps us to ensure we are providing consistent, quality grain to meet our end use customer and regulatory requirements.

“The new equipment means we no longer need to outsource chemical residue testing, which could take up to ten working days, and allows us to be more efficient.

“The new equipment supports our state of the art laboratory and food safety and quality standards which meet the highest standards globally.”

James says that in combination with what grain handlers do, it is still important that growers follow label use instructions so access to markets is not limited or put at risk.

“It is a joint effort where everyone through the supply chain has a role to play so that overall, regulatory requirements are met, market access for our grain is maintained, buyers and end users continue to want to source their grain from South Australia, and importantly, we all remain safe.”

IMI tolerant barley varieties

Earlier this year, industry warned growers to carefully consider the use of imidazolinone chemicals, more commonly known as IMI, to their Spartacus and Scope malting barley varieties due to potential market access restrictions for IMI tolerant barley varieties.

South Korea and Japan are key markets for Australian barley and currently have MRLs below the residues allowed in Australia for IMI chemicals. The disparity between the importing and exporting countries MRLs is what could potentially create market access restrictions.

James Murray says that for the 2019/20 harvest, growers delivering to Viterra will be asked to declare if they have applied IMI chemicals to their barley on their delivery advice and declaration form.

“Spartacus and Scope varieties that have had IMI applied will still be received as a malting barley grade provided the load meets all other quality requirements,” James said.

“We have decided to implement a declaration based on feedback we received in our planting survey.

“This declaration is critical to assist us with managing stock with IMI applied, to help us meet end use customer needs and importing countries’ MRLs.

“We continue to monitor the discussion occurring between industry, government and importing country authorities on market access requirements and market acceptance of IMI applied barley.”

The APVMA recommends that growers always follow the safety and use directions on the label for chemicals and pesticides. Usage rules can differ from state to state, so the APVMA recommends checking the label and if in doubt, contacting the local state or territory department of agriculture.

If growers are unsure about a chemical and whether it’s been registered for use, visit the chemical or permit database,

For more information, visit the APVMA website