Australia refuses dimethoate used for export tomatoes

The Australian Pesticides and Veterinary Medicines Authority (APVMA) has confirmed its original decision to refuse a permit application from a horticultural exporter for use of dimethoate as a post-harvest treatment for export tomatoes. This follows a formal request from the applicant to reconsider the original decision.

Dr Raj Bhula, Pesticides Program Manager for the APVMA said that where the APVMA could not be satisfied that all relevant legal tests had been met for the permit application, then the APVMA must refuse the application.

"Dimethoate is an organophosphorous (OP) insecticide and exposure to OP pesticides can result in both acute and chronic health effects,” said Dr Bhula.

"The human health risk assessment prepared by the Office of Chemical Safety raised concerns that exposure of children to dimethoate may be harmful to their development.

"Our August 2011 Residues and Dietary Risk Assessment Report concluded that the post-harvest use of dimethoate on tomatoes and certain other food crops was unacceptable. This is because of potential dietary exposure risks for children”, said Dr Bhula.

As a result of this conclusion, on 6 October 2011, the APVMA suspended the use of dimethoate on a number of food crops.

On 17 October 2011, the horticultural exporter applied for a permit to use a dimethoate product as a post-harvest fruit fly treatment for tomatoes “for supply interstate and export to New Zealand and the Pacific Islands”.

The application included new residue data that the APVMA assessed. The APVMA raised concerns about dietary exposure risks with the applicant prior to making its original decision.

The number of tomatoes that would need to be consumed to amount to an acute exposure is low. The consumption data used in the assessment was 168 g for 2–6 year olds and 351 g for the general population. Based on Australian survey data the ‘average’ tomato (non-cherry/grape) weighs 130g. This equates to consumption of 1.3 tomatoes for a 2–6 year old or 2.7 tomatoes for a member of the general population over 6 years old in a 24 hour period. Based on our exposure estimates, the proposed use could not be approved.

After carefully considering all the facts, the APVMA could not be satisfied that the proposed use of the product would not be an undue hazard to people using anything containing its residues and would be likely to have an effect that is harmful to human beings. We were therefore obliged by our legislation to refuse the permit application.

The horticultural exporter wrote to APVMA in January 2012 requesting a reconsideration of the original decision, saying that the permit is “only for the purpose of treating tomatoes, specifically for export to New Zealand”.

Having determined the reconsideration request to be valid, the APVMA invited the horicultural exporter to submit any new information or argument that could be taken into account during the reconsideration.

The horticultural exporter argued that:

• the MRL for dimethoate in tomatoes in New Zealand is 1 mg/kg [the current Australian MRL is 0.02 mg/kg]
• references in the Agvet Code to the safety of human beings, animals and the environment can only refer to human beings, animals and the environment in Australia
• the preamble to the Agvet Code requires the APVMA to apply the Code in a way that furthers trade and commerce between Australia and places outside Australia
• test results are well under the New Zealand MRL, except for one result which fell under the New Zealand MRL shortly after treatment
• use of dimethoate as proposed is not an undue hazard to the people of Australia during handling, or from residues as the tomatoes will not be eaten in Australia
• there is no international Codex MRL for dimethoate, and the APVMA’s estimate of the chronic dietary exposure that would be done to set a Codex MRL for international trade is irrelevant.

Each of these factors was considered in detail by the APVMA. The APVMA acknowledges there are differences between the Australian and New Zealand regulatory requirements for the use of dimethoate, including different maximum residue limits. There are also differences in the methodologies used to estimate the exposure risks to consumers.

A critical consideration for the APVMA was whether the reference in our legislation to “human beings” was to be interpreted as “Australian citizens”. While there are competing issues to consider here, the legislation highlights the importance of the safety of human beings and international trade and commerce, indicating that the APVMA’s considerations are not confined to matters pertaining to Australia, and in particular, that APVMA may have regard to the safety of human beings beyond Australia’s boundaries where relevant.

The APVMA’s governing legislation provides for consideration of trade and commerce between Australia and places outside Australia and good government practice suggests the APVMA should not unnecessarily hinder trade as part of its decision-making.

"However, this is a secondary consideration to the importance given by our governing legislation to the protection of the health and safety of humans. In addition to the overarching intent of the legislation, there are specific legal tests that must be met and these are paramount in our decision making”, said Dr Bhula.

In the case of the use proposed by the horticultural exporter, the residues of dimethoate on tomatoes would be greater than the limit that the APVMA has approved. Residue data provided by the horicultural exporter shows that the residue amount of dimethoate at seven days after treatment will be 0.36mg/kg and 0.20 mg/kg 13 days after treatment. The presence of that amount of dimethoate residue is likely to have an effect that is harmful to human beings both in terms of chronic and acute exposure.

After carefully considering all of the relevant facts relating to the proposed use under the permit application, the APVMA delegate concluded that the use of dimethoate on tomatoes destined for export to New Zealand would not unduly prejudice trade between Australia and places outside Australia. However, the delegate could not be satisfied that the proposed use would not be an undue hazard to the safety of people using anything containing its residues, and could not be satisfied that the proposed use would not be likely to have an effect that is harmful to human beings. Consequently the APVMA affirmed its original decision to refuse permit application 13172.