Scientific Opinion on the safety and efficacy of aliphatic and aromatic mono- and di-thiols and mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups (chemical group 20) when used as flavourings for all animal species


Panel on Additives and Products or Substances used in Animal Feed
EFSA Journal
EFSA Journal 2013;11(5):3208 [34 pp.].
Panel Members
Gabriele Aquilina, Alex Bach, Vasileios Bampidis, Maria De Lourdes Bastos, Lucio Guido Costa, Gerhard Flachowsky, Mikolaj Antoni Gralak, Christer Hogstrand, Lubomir Leng, Secundino López-Puente, Giovanna Martelli, Baltasar Mayo, Fernando Ramos, Derek Renshaw, Guido Rychen, Maria Saarela, Kristen Sejrsen, Patrick Van Beelen, Robert John Wallace and Johannes Westendorf

The Panel wishes to thank the members of the Working Group on Feed Flavourings, including Georges Bories, Paul Brantom, Andrew Chesson, Joop de Knecht, Jürgen Gropp and Anne-Katrine Lundebye Haldorsen, for the preparatory work on this scientific opinion.

Opinion of the Scientific Committee/Scientific Panel
On request from
European Commission
Question Number
17. April 2013
Published in the EFSA Journal
13. Mai 2013
Last Updated
3. Juni 2013. This version replaces the previous one/s.
European Food Safety Authority (EFSA), Parma, Italy

Chemical group 20 consists of aliphatic and aromatic mono- and di-thiols and mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups, of which 31 are currently authorised for use as flavours in food. The FEEDAP Panel was unable to perform an assessment of six compounds (methanethiol, methyl propyl disulphide, dipropyl trisulphide, 3-mercaptobutan-2-one, 3-(methylthio)butanal and 3-methyl-1,2,4-trithiane) because of issues related to the purity of the compounds. The FEEDAP Panel concludes that the following 25 compounds are safe for the target species at the proposed maximum dose level (0.05 mg/kg complete feed): 3-(methylthio)propionaldehyde, methyl 3-(methylthio)propionate, allylthiol, dimethyl sulphide, dibutyl sulphide, diallyl disulphide, diallyl trisulphide, dimethyl trisulphide, dipropyl disulphide, allyl isothiocyanate, dimethyl disulphide, 2-methylbenzene-1-thiol, S-methyl butanethioate, allyl methyl disulphide, 3-(methylthio)propan-1-ol, 3-(methylthio)hexan-1-ol, 1-propane-1-thiol, diallyl sulphide, 2,4-dithiapentane, 2-methyl-2-(methyldithio)propanal, 2-methylpropane-1-thiol, methylsulfinylmethane, propane-2-thiol, 3,5-dimethyl-1,2,4-trithiolane and 2-methyl-4-propyl-1,3-oxathiane. No safety concern for the consumer would arise from the use of these 25 compounds of CG 20 up to the highest safe level in feedingstuffs for all animal species, with the exception of allyl isothiocyanate. Although additional exposure to this substance through its low use level in animal feeds would not substantially increase consumer exposure, the FEEDAP Panel notes that the estimated exposure of consumers is already higher than the acceptable daily intake (ADI). All compounds should be considered irritant to skin, eyes and respiratory tract and as skin sensitisers. The proposed concentration of 0.05 mg flavour/kg feed is not expected to cause detrimental effects to the environment, except for 2-methylpropane-1-thiol, for which 0.04 mg/kg is expected to be safe. Since all 25 compounds are used in food as flavourings and their function is essentially the same as that in food, no further demonstration of efficacy is necessary.

Sensory additives, flavourings, aliphatic and aromatic mono- and di-thiols and mono-, di-, tri- and polysulphides with or without additional oxygenated functional groups, chemical group 20
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