Hexachlorobenzene (HCB) is a persistent (poorly degradable) organic pollutant that is ubiquitously distributed in the environment and accumulates in the food chain due to its high lipid solubility. HCB is referred to as a "POP" ("persistent organic pollutant"). Due to its harmful properties, HCB was banned for agricultural use (fungicide) in the European Community in 1981. HCB is one of 12 chlorine compounds that were banned worldwide by the Stockholm Convention in 2004.
Since hexachlorobenzene is ubiquitous in the environment, there are also residues of it in food and feed. HCB has also been used in the production of explosives and synthetic rubber, and is formed as a by-product in the synthesis of various organic compounds. Inputs to the environment in the past were mainly from the use of HCB as a fungicide in agriculture and from emissions from industry and combustion processes. Today, contaminated sites (landfills) can still act as a source of inputs to the environment.
Situation in Austria
Maximum residue levels in food and feed are regulated by law in Regulation (EC) No. 396/2005 of the European Parliament and of the Council of February 23, 2005, as amended.
We regularly test food and feed for the banned active ingredient HCB as part of official food inspections. Exceedances of the maximum levels are usually only detected in pumpkin seeds and pumpkin seed oils.
Our risk assessments on the situation in the Görtschitz Valley 2014/2015 can be found here. Information from the Carinthian provincial government on this can be found here.
The maximum levels set in the European Union apply only to primary products (agricultural raw material e.g. milk) while for processed products (e.g. butter, curd...) the result is related to the fat content of the starting product. Thus, there is only one fixed maximum value for milk, but no specifically fixed maximum values for dairy products such as butter, curd, etc. Therefore, the maximum value for milk of 0.005 mg/kg cannot be transferred 1:1 to butter, even if the measured value in butter is higher. Therefore, for butter, the value in the milk from which this butter was produced is calculated on the basis of its fat content.
The different maximum levels for HCB result from the particularly good fat solubility of HCB: the higher the fat content in the food, the higher the limit value. It must be noted that a mere exceeding of the maximum levels per se is not associated with a health hazard, but in any case requires a separate expert evaluation.
A specific query on the maximum residue levels of hexachlorobenzene in food and feed can be carried out on the following database (information onpesticides, residues, hexachlorobenzene):EU database on pesticide residues.
Risk assessment HCB 2014/2015 for the Görtschitz Valley
Risk assessment HCB 2009 - 2015 for Austrian population
National pesticide control program 2019
Stockholm Convention: the "dirty dozen
EU Pesticide Monitoring Report
Federal Environment Agency: Hexachlorobenzene
Federal Environment Agency: Atlas of contaminated sites
Information page of the State of Carinthia on HCB Görtschitztal
Risk management to minimize HCB contamination in oil pumpkin
Last updated: 13.03.2023