Addressing Pesticide Residue

The European Union, through the newly formed European Food Safety Authority (EFSA), is widely recognized as one of the strictest regulatory agencies in the world governing the production and distribution of consumable agricultural products. Whether its zeal is driven by France’s long standing claim as the birthplace of gastronomy or the fact that many countries with different food traditions share patch-worked borders or by consumer concern for food safety fueled by well- publicized scares over BSE in beef, Salmonella in eggs and dioxins in pâté, it is clear that the policies the EFSA has set forward leave little room for missteps in the assurance of food quality.

One of the key areas regulated by the European Commission and the EFSA is the use of plant protection products – insecticides, fungicides and herbicides. In 1991, a harmonized authorization system was established to ensure that these active substances could be evaluated, controlled and made public on an EU-wide basis with the idea that an active substance cannot be used unless it is included on a positive EU list. At the time the directive was adopted, there were over 800 such substances authorized for use in the member states.

In 1992, the EU embarked on a total review of all plant protection products that is expected to be completed in 2008. The fate of the products in question rests almost entirely with the manufacturers who must “defend” their substances (i.e., prove that they meet the required safety standards). The scrutiny has led to a number of the older active compounds being withdrawn either for reasons of toxicity, efficacy or environmental impact, or simply because the regulatory hurdles and financial burden of providing adequate scientific data to support an approval were too onerous. As a result, by 2003 almost 50 percent of the original plant protection substances had been deemed unsuitable to remain on the market and have already been withdrawn or will be shortly.

When a compound is de-listed, its maximum permitted residue level (MRL) in food reverts to the limit of detection (LOD) which in the EU is typically set at 0.01 mg/kg (10 mg/kg or 10 parts per billion(ppb)). Proposed new MRL legislation being considered is to set a common LOD of 10 mg/kg for any commodity/pesticide combination for which a higher level cannot be justified.

MRLs reflect levels of pesticides that are expected to be found in produce that has been treated in accordance with good agricultural practices. Where pesticides do not give rise to readily detectable residues, or are not approved for use on particular commodities, MRLs are set at the lowest level that can be identified in routine laboratory analysis – effectively a zero. Although MRLs are not safety limits, generally being set well below a level that could cause concern for consumers’ health, they remain the statutory tool used to ensure legal compliance.

Globalizing MRLs

In an effort to internationalize their efforts and level the playing field for member states to participate in the increasingly global market for agricultural products, the EFSA consults with the World Trade Organization (WTO) on all new MRLs before they are issued. This doesn’t necessarily ensure that standards are the same from country to country, but does signal that harmonizing production is still the goal.

One example of how the MRLs remain country-specific, however, is the proscribed limits on chlorpropham – a growth regulator used in potatoes to suppress sprouting during storage. The MRL in the UK and throughout most of the EU is 0.5 mg/kg, while in Sweden the limit is 10 times less at 0.05 mg/kg and the U.S. Environmental Protection Agency (EPA) has set the limit at 50 mg/kg. This indicates not only the ongoing inconsistencies, but the very strict limits allowed (in the U.K. and across the continent) by the European authorities.



    Of course, one of the most important area of food science is that of food safety.
    It is a good article.

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