Chlorate in Fish and Seafood
Feb 2020. The precautionary recall of fish products in the recent past has led to uncertainties as to the quantity above which elevated chlorate levels in fish and seafood are to be considered a risk to the health of consumers. Eurofins summarises the situation and provides concrete guidance for the analysis and evaluation of chlorate.
Analysis and evaluation of chlorate*
Here you will find more detailed information for free download.
*Author: Markus Paul, Eurofins NDSC Food Testing Germany
Use of Chlorate and Occurrence in Food
Chlorate is a so-called multi-source substance that has been used as a herbicide, but also as a disinfectant (biocide). The use of chlorate as a pesticide or in biocidal products is no longer lawful in the EU. However, its use as a disinfection by-product from the lawful treatment of drinking water with chlorine-containing products can lead to residues in food.
In Germany, this problem plays only a minor role domestically. The benchmark for chlorate in drinking water recommended by the World Health Organization (WHO) is used in Germany only for short-term emergencies at best. However, in countries where chlorination of drinking water is common, contact with water is the main entry phase in food. Eurofins internal spot checks showed that depending on whether samples were analysed with or without water glaze, different chlorate contents were found and they were significantly higher in the samples with water glaze. In this context, when testing chlorate, it should be taken into account that the food has to be tested in the same way as it is consumed.
No Legal Maximum Level for Chlorate in Fish or Seafood
The maximum residue levels for chlorate established by EU Regulation 2020/749 of 4 June 2020 amending Annex III to EU Regulation 396/2005 do not apply to fish and seafood, as in this case the evaluation of plant protection products is carried out in accordance with the RHmV (regulation governing maximum values of residues of pesticides and insecticides and other agents in or on foodstuffs) and a toxicological evaluation is carried out accordingly. A legal maximum value for chlorate in fish or seafood has not yet been set.
Inconsistent Approach by Officials
Different calculation models have been used by German officials for the public recalls carried out so far. This is due to the non-standard procedure on the German federal state level. Portion sizes, groups of persons and body weights were also estimated differently and contrasted with the ARfD value.
In addition, trading partners have the most varied standards and define the most varied maximum values of chlorate in their specifications. In this case, the contractually agreed values must be adhered to.
How Are Chlorate Contents in Fish and Seafood to Be Classified?
According to the EFSA SCIENTIFIC Opinion "Risks for public health related to the presence of chlorate in food" of 24 June 2015, the ARfD value of 0.036 mg/kg of body weight determined there must be taken into consideration for the toxicological assessment. The ARfD value refers to the acute reference dose defined by the WHO, i.e. the volume of substance which can be ingested through food with a meal or within one day without recognisable risk for the consumer. It is usually calculated for the most at-risk population group: infants.
For an infant living in Germany with an exemplary average weight of 16.15 kg, 100% ARfD utilisation here corresponds to a content of 4.1 mg chlorate/kg foodstuff.
In addition, further means can be consulted to evaluate the average toxicological exposure, such as the EFSA study "Compiled European Food Consumption Database" or the so-called VELS-Study of the BfR (German Federal Institute of Risk Assessment: Consumption Study for the Assessment of an Acute Toxicity Risk from Pesticide Residues - in German).
Since measurement uncertainties are individual depending on the analytical method used, we recommend coordinating these with your Eurofins laboratory.
A detailed description of the analysis and evaluation of chlorate can be found in the Eurofins document Chlorate in Fish and Seafood, which is available for download free of charge.
Do You Have Questions about Chlorate Levels in Fish and Seafood?
Please do not hesitate to contact your personal account manager or directly the author of the Eurofins document Chlorate in Fish and Seafood, Markus Paul.
