Semicarbazide is used as an indicator of the use of the banned nitrofan antibiotic substance nitrofurazone in poultry products. It is a weak carcinogen however, and is banned in the EU.
Data from the Brazilian agricultural ministry showed that before the implementation of the Brazilian nitrofuran control programme in February 2003, the cases of contamination of Brazilian chicken by nitrofurans were due to the metabolite furaltadone. However, once the control programme was functioning the reports of the contamination with this nitrofuran declined.
But in April 2003, an increase in samples containing semicarbazide was reported. Further investigation showed that most of the chicken products containing semicarbazide had been coated with flour, salt and spices.
The authors subsequently discovered that azodicarbonamide, a substance used as a flour-improving agent in Brazil and the US, was the source of the semicarbazide. This is of significance because it may give rise to false positives in the testing of Brazilian poultry products for nitrofurans.
The study was carried out by scientists from the Galeno Research Unit in Brazil, and the findings have just been published in the January 2004 issue of the journal Food Additives and Contaminants.
Scientific consultancy firm RSSL reports that in July 2003, the European Food Safety Authority (EFSA) was notified that a decomposition product of azodicarbonamide, semicarbazide (SEM), had been found at concentrations in baby foods, as well as in other foods packed in glass jars.
The EFSA's scientific panel subsequently advised that there was a health risk to both infants and adults from eating foods containing SEM.
This ban was contained in Commission Directive 2004/1/EC of 6 January 2004, amending Directive 2002/72/EC, and suspended the use of azodicarbonamide as blowing agent in plastic materials and articles that are intended for food contact. Azodicarbonamide has been used as a blowing agent in the manufacture of plastic gaskets for use in the metal lids used for the closure of glass jars.