Scientific Opinion on re-evaluation of one flavouring substance 3-acetyl-2,5-dimethylthiophene [FL-no 15.024] from FGE.19 subgroup 5.2

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Article
EFSA Journal 2013;11(5):3227 [10 pp.].
doi
10.2903/j.efsa.2013.3227
EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)
Panel Members
Ulla Beckman Sundh, Mona-Lise Binderup, Claudia Bolognesi, Leon Brimer, Laurence Castle, Alessandro Di Domenico, Karl-Heinz Engel, Roland Franz, Nathalie Gontard, Rainer Gürtler, Trine Husøy, Klaus-Dieter Jany, Martine Kolf-Clauw, Catherine Leclercq, Wim Mennes, Maria Rosaria Milana, Iona Pratt, Kettil Svensson, Maria de Fatima Tavares Pocas, Fidel Toldra and Detlef Wölfle
Acknowledgement

The Panel wishes to thank the members of the Genotoxicity Working Groups on Flavourings: Mona-Lise Binderup, Claudia Bolognesi, Wilfried Bursch, Angelo Carere, Riccardo Crebelli, Rainer Gürtler, Daniel Marzin, Pasquale Mosesso for the preparatory work on this scientific opinion and the hearing experts: Vibe Beltoft, Pia Lund and Karin Nørby and EFSA staff: Maria Carfi, Annamaria Rossi and Kim Rygaard Nielsen for the support provided to this scientific opinion.

Contact
Type
Opinion of the Scientific Committee/Scientific Panel
On Request From
European Commission
Question Number
EFSA-Q-2013-00323
Adopted
15 May 2013
Published
16 May 2013
Last Updated
4 June 2013. This version replaces the previous one/s.
Affiliation
European Food Safety Authority (EFSA), Parma, Italy
Note
Article (133.13 KB)133.13 KB
Abstract

The 26th Plenary meeting of the AFC Panel on 27-29 November 2007 discussed the flavouring group evaluation 19 (FGE.19) which included alpha, beta-unsaturated aldehydes or ketones considered to be a structural alert for genotoxicity. The flavour industry was requested to submit data on genotoxicity of 3-acetyl-2,5-dimethylthiophene [FL-no 15.024] (subgroup 5.2 in the FGE.19; the other substances of this subgroup were evaluated in FGE.224). An in vitro bacterial mutation assay was positive in Salmonella typhimurium strains TA98, TA100 and TA102 in the presence of rat liver metabolic activation system (S9-mix), and an in vivo study on mutant frequency in Muta™Mice was positive in liver after exposure to 3-acetyl-2,5-dimethylthiophene. Based on this outcome the CEF Panel considered 3-acetyl-2,5-dimethylthiophene as mutagenic in vitro and in vivo and concluded that its use as flavouring substance raises a safety concern.

Summary

Following a request from the European Commission, the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids was asked to deliver a scientific opinion on re-evaluation of one flavouring substance 3-acetyl-2,5-dimethylthiophene [FL-no 15.024] from FGE.19 subgroup 5.2.

In the 26th Plenary meeting of the AFC Panel on 27-29 November 2007, EFSA discussed the flavouring group evaluation 19 (FGE.19) including flavouring substances which are alpha, beta-unsaturated aldehydes or ketones or precursors thereof. These structures are considered to be a structural alert for genotoxicity. 3-Acetyl-2,5-dimethylthiophene [FL-no 15.024] belongs to subgroup 5.2 in the FGE.19.

In 2013 the CEF Panel concluded in its Scientific Opinion on FGE.224 (EFSA, 2013) that for the substance 3-acetyl-2,5-dimethylthiophene [FL-no 15.024] no conclusion could be taken due to the lack of data on genotoxicity.

The missing data has now been submitted by the European Flavour Association to the European Commission which asked EFSA to evaluate this new information.

The data submitted consist of an in vitro bacterial mutation assay and an in vivo Muta™Mice study which were performed in compliance with Good Laboratory Practice and according to the OECD Guideline 471 and 488, respectively.

The bacterial mutation assay shows a dose-dependent positive outcome in the strains TA98, TA100 and TA102 in presence of Aroclor induced rat liver S9-mix (at non toxic concentrations), indicating that the mutagenicity observed in this assay is due to a metabolite of the substance.

In addition, an in vivo study in Muta™Mice has been performed monitoring mutant frequency in liver and duodenum, and counting of micronucleated reticulocytes in the peripheral blood. Results from this study showed a dose dependent increase in the mutant frequency for liver, while no dose-related effects where observed for mutant frequency in duodenum nor was an increase in micronucleated reticulocytes observed. The results of the in vivo study further support the hypothesis that the mutagenicity observed is due to a metabolite of the 3-acetyl-2,5-dimethylthiophene.

The CEF Panel concluded that 3-acetyl-2,5-dimethylthiophene is mutagenic both in vitro and in vivo and that therefore its use as flavouring substance raises a safety concern.

Keywords
FL-NO 15.024, 3-ACETYL-2,5-DIMETHYLTHIOPHENE, FGE.19, SUBGROUP 5.2
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Number of Pages
10