The occurrence of SEM in foods, including baby foods, packaged in glass jars and bottles, was first discovered by industry and its origins were traced to the breakdown of azodicarbonamide, the foaming agent in the plastic gaskets that are used to seal metal lids to glass packaging. Industry informed EFSA of this finding in 2003 and of its intention to develop gaskets using an alternative foaming agent. The EFSA AFC Panel* at that time advised that while the risk to consumers – if any – was very small, SEM should be removed from baby foods as swiftly as technological progress allowed. This advice was based on findings that SEM is a weak carcinogen in mice and has weak genotoxic activity (i.e. potential to damage genetic material or DNA) in vitro. Since then, new studies showing lack of genotoxic activity of SEM in vivo have become available. The Panel has concluded that this new information reduces concerns about SEM and that the issue of carcinogenicity is not of concern for human health, given the levels of SEM reported during 2003 and 2004 in foods packaged in glass jars and bottles. The implementation of an EC Directive banning the use of azodicarbonamide in plastics used as food contact materials** which is due to enter into force on 2 August 2005 should eliminate this source of SEM in food. The Panel also concluded that other, lesser sources of SEM in food were not of concern.

The Chair of the AFC Panel, Dr Sue Barlow, said “We welcome these new findings that reduce our former concerns about low exposures to SEM from food packaging and give further support to our earlier view that the risks – if any – are very small. Removal of the major source of SEM in food will further reduce exposure and contribute to building consumer confidence in such foods, especially for babies.”

Following EFSA’s previous advice, the European Commission asked EFSA to carry out a wider review on the occurrence of SEM in food and to assess possible risks associated with levels of exposure found in the diet. In its new opinion, EFSA’s AFC Panel has identified 5 possible sources of SEM contamination or occurrence in food. By far the most important source is that identified in EFSA’s first opinion through the transfer of SEM to certain foods packed in glass jars and bottles closed with metal lids sealed with plastic gaskets, such as baby food, jams, pickles, mayonnaise and ketchup. Food for infants has been re-confirmed as the most important source of exposure. However, it is anticipated that this source of exposure will soon be eliminated through the introduction of a new sealing technology.

The other four less significant sources of SEM contamination in food identified by the Panel are:

• From the use in animals of the illegal veterinary antibiotic drug nitrofurazone. This route of contamination should be rare because of the application of existing EU rules.
• As a by-product from the reaction of residues of chlorine-based products, such as hypochlorite bleach, with food following cleaning of food equipment, or from the use of hypochlorite in the production of food additives.
• From the decomposition of the dough improver, azodicarbonamide, in flour. Although use of azodicarbonamide as a dough improver is illegal in the EU, SEM can occur in very small quantities in imported bread products and coverings, such as bread crumb food coatings.
• Background levels of SEM from as yet unidentified or possibly natural sources.

The Panel concluded that these sources contribute very little to the intake of SEM.

*Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food 

**Commission Directive 2004/1/EC amending Directive 2002/72/EC as regards the suspension of the use of azodicarbonamide as blowing agent