Opinion of the Scientific Panel on contaminants in the food chain [CONTAM] related heptachlor as an undesirable substance in animal feed

  EFSA Panel on Contaminants in the Food Chain (CONTAM) Panel Members Jan Alexander, Guðjón Atli Auðunsson, Diane Benford, Andrew Cockburn, Jean-Pierre Cravedi, Eugenia Dogliotti, Alessandro Di Domenico, Maria Luisa Férnandez-Cruz, Peter Fürst, Johanna Fink-Gremmels, Corrado Lodovico Galli, Philippe Grandjean, Jadwiga Gzyl, Gerhard Heinemeyer, Niklas Johansson, Antonio Mutti, Josef Schlatter, Rolaf van Leeuwen, Carlos Van Peteghem, Philippe Verger. Acknowledgment The Scientific Panel on Contaminants in the Food Chain wishes to thank Jan Alexander, Guðjón Atli Auðunsson, Aksel Bernhoft, Jean-Pierre Cravedi, Peter Fürst, Niklas Johansson and Olaf Päpke for the preparation of the draft opinion.
Type: Opinion of the Scientific Committee/Scientific Panel Question number: EFSA-Q-2005-184 Adopted: 26 April 2007 Published: 05 June 2007 Last updated: 05 June 2007

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Heptachlor was commercially introduced as a non-systemic contact insecticide in 1945. It was also a major constituent (about 10 %) of technical chlordane. Heptachlor was used for agricultural purposes, soil and seed treatment, wood protection and termite- and household insect control. It has been banned for use in the European Union since 1984 and in most other countries worldwide because of the persistency in the environment of the two break-down products heptachlor epoxide and photoheptachlor. All these compounds are lipophilic and particularly heptachlor epoxide and photoheptachlor tend to accumulate in the food chain.

Heptachlor shows moderate acute toxicity and heptachlor epoxide and photoheptachlor are more toxic than heptachlor. In mammals, the main target organs are the nervous system and the liver, but also the reproductive and the immune system are affected. Heptachlor and heptachlor epoxide cause liver tumours in mice, but are not genotoxic. Heptachlor is classified by IARC as possibly carcinogenic to humans (group 2B). Heptachlor is moderately or highly toxic to fish exposed via water, but no data from oral studies have been found.

Amongst the species studied, the domestic hen is the most sensitive species and egg production and hatchability are the critical endpoints. Total heptachlor (sum of heptachlor and heptachlor epoxide) is not frequently found in feed commodities. When present, it is mostly in fish derived products and only very infrequently in feed materials of plant origin. Heptachlor epoxide is the predominant contaminant. The concentrations found in feed are in the low mg/kg range and thus well below those that have been found to cause adverse effects in animals. The half-life of total heptachlor varies from several days in rodents up to more than 20 weeks in non-lactating cattle. Following heptachlor exposure, only heptachlor epoxide is found in milk and eggs. The present dietary exposure of the adult population to total heptachlor is below 1 ng/kg b.w. per day, which is two to three orders of magnitude below the tolerable daily intake of 0.0001 mg/kg b.w. as established by WHO in 2006.


K animal feed, toxicity, analysis, occurrence, metabolism, bioaccumulation, animal health, carry-over, human health.v EYWORDS: Heptachlor, heptachlor epoxide, photoheptachlor, persistence, insecticide,