The risks of genotoxicity and tumors (carcinogenesis) associated with smoke flavorings used in various categories of foods have been well-known – in scientific literature and in the opinions of the authorities responsible for risk assessment (EFSA in the EU, FDA in the USA) – for at least 20 years.
The European Commission, instead of taking emergency measures to ban the use of these dangerous chemicals immediately, decided to allow their use until 2029. And one of their manufacturers, Kerry Ingredients, has contested the decision not to renew their authorization.
However, these elements must be considered both by citizens, to protect their health, and by retail and the food industry, to ensure food safety and the integrity of their supply chains. In addition to preventing any economic and reputational risks.
1) Smoking and smoking flavors
The smoking consists of indirect cooking of food (e.g. meat, fish, cheese), over a fire or a smoke generating system. It is one of the oldest food preservation techniques, whose history is attributed to the Neolithic period, over 10,000 years ago. And it is still used to give foods a characteristic flavor. Smoke gives foods several hundred compounds, some of which have antioxidant and antimicrobial action, others (e.g. carbonyl compounds, phenols, organic acids) give foods the color and consistency typical of smoking.
The woods and the processes used (i.e. incomplete combustion of organic materials) can also cause the formation of toxic chemicals such as polycyclic aromatic hydrocarbons (PAHs), some of which are considered carcinogenic.
Smoke aromas were developed in the late 19th century as a substitute for the traditional smoking process. They are produced by controlled thermal degradation of wood with a limited supply of oxygen (pyrolysis), subsequent condensation of the vapours and fractionation of the resulting products. The primary products thus obtained (primary smoke condensates and primary tar fractions) can be further processed to produce smoke flavourings that can be applied to the inside or surface of foods.
2) Smoke flavourings, the EU rules
Smoke Flavourings Regulation (EC) No 2065/2003 establishes the common procedure for the evaluation and authorisation of smoke flavourings such as primary smoke condensates (purified aqueous part of condensed smoke) and primary tar fractions (purified fraction of the water-insoluble high density tar phase of condensed smoke), also referred to as ‘primary products’. These can be used either as such or in the production of smoke flavourings (food additives).
Production requires that the wood used – to which herbs, spices, juniper twigs and Picea twigs, needles and cones may be added (1) – is certified as having been free from chemical treatments in the six months before and after the felling of the shrub (except for demonstration of the safety of any toxic substances present following combustion). The basic material is subjected to controlled combustion, dry distillation or treatment with superheated steam with a limited supply of oxygen at a maximum temperature of 600 °C.
Condensed smoke may be isolated, fractionated and purified by physical processes, as well as treated with water and authorised solvents (pursuant to Directive 2009/32/EC), to obtain primary products (smoke flavourings). Which must comply with a maximum content of the following polycyclic aromatic hydrocarbons (PAHs):
– benzo(a)pyrene (BaP), 10 μg/kg;
– benzo(a)anthracene (BaA), 20 μg/kg.
3) Risk analysis
All smoke flavorings (primary products) are subject to a renewable 2-year authorisation in the European Union, following an assessment of their safety by EFSA (European Food Safety Authority). The authorisation requests include information on the wood used, the production methods, the chemical composition (qualitative and quantitative) of the primary products and the characterisation of the unidentified fraction, the levels of use envisaged, and the toxicological data based on the EFSA guidelines. (2)
The identification, sampling and characterisation of the primary product are subject to a validated analytical method, subject to the quality criteria laid down in Regulation (EC) No 627/2006. The analyses – as well as the safety assessment of smoke flavourings, in more general terms – focus on the 15 polycyclic aromatic hydrocarbons (PAHs) identified as carcinogenic and genotoxic already prior to the adoption of the aforementioned Regulation (EC) No 627/2006.
4) Smoke flavourings authorised in the EU
The positive list (i.e. exclusive and binding) of smoke flavouring primary products authorised in the European Union is defined by Implementing Regulation (EU) No. 1321/2013. Which initially contained 10 primary products identified by a unique code (SF-0XX), their specifications, conditions of use, and the dates of authorisation (renewal) and expiry. With further provisions, which concern:
– the maximum levels of primary products in food, with specific provisions for dried and concentrated products;
– the proportional reductions of the individual contents in the combinations of smoke flavourings;
– compliance with Good Manufacturing Practices (GMPs) of smoking chambers used for the regeneration of smoke in processed meat, fish and processed fishery products;
– limitations on their use, in compound foods, only to products containing an ingredient where the use of smoke flavourings is permitted;
– the ban on use in Foods for Specific Groups (FSGs), such as infant formula, follow-on formula and baby foods, processed cereal-based foods and dietary foods for special medical purposes.
4.1) Revocation of authorisations and transitional period
The implementing regulation (EU) 2024/2067 – following the EFSA scientific evaluation (2023) on the genotoxicity and carcinogenicity of smoke flavourings included in the list referred to in the previous paragraph – has revoked their authorisation for use in the European Union.
The European executive has however provided for a long transitional period that allows the marketing of such primary products for the following two or five years, depending on the foods in which their use is envisaged. Until:
– July 1, 2029, for foods in categories 1.7 (cheese and dairy products), 8 (meat), 9.2 (processed fish and fishery products, including molluscs and crustaceans), 9.3 (fish eggs) and their respective subcategories; (3)
– July 1, 2026, for all other food categories.
4.2) Litigation before the Court of Justice of the EU
European Flavor Association welcomed the European decision, which will certainly stimulate research and development of even natural flavours suitable for meeting the demands of the food industry and the expectations of consumers without presenting food safety risks. (4)
Kerry Inc. and Kerry Ingredients (UK) Ltd have instead brought an action against the Commission before the Court of Justice of the European Union, seeking the annulment of the implementing regulations which rejected their requests for renewal of the authorisation for the use of their smoke flavourings.
Kerry’s main accusation against EFSA and the Commission, concerns considering the risks of these substances in generic terms, without due consideration of the safety studies attached by the applicant on its products. (5)
5) Genotoxicity and tumors, the identified risks
The formation and the content of polycyclic aromatic hydrocarbons have been extensively studied in recent decades, both in traditionally smoked products (e.g. fish, meat and cheese) and in smoke flavourings. This class of compounds is of particular interest since some of them contain carcinogenic and genotoxic substances (i.e. BaP, BaA), whose maximum levels have been defined both in smoke flavourings and in some food categories through the Food Contaminants Regulation (EC) No 1881/2006. (6)
The potential genotoxicity of pyrolysis products, the subject of early studies since the 1990s, was investigated in depth on primary flavoring smoke products in several research studies and observed by EFSA, between 2007 and 2012, in in vitro tests on all substances later included in the list in paragraph 4 above. The genotoxicity revealed in bacterial gene mutation tests and/or mammalian cell tests, however, had not been confirmed in animal studies (Theobald et al., 2012). (7)
EFSA’s subsequent analysis (2023) instead identified, in six of the eight primary products evaluated, the presence of another compound – furan-2(5H)-on – which has been shown to be genotoxic in vivo. Four of these primary products also contain 1,2 dihydroxybenzene, which is also genotoxic in vivo. The application of new criteria for the assessment of the risk of genotoxicity and the genotoxicity of chemical compounds (8,9), as well as harmonized analysis methods at OECD level (live comet assay), led EFSA experts to evaluate these risks as unacceptable.
6) Common data platform on chemicals
On December 7, 2023 the European Commission had also presented a proposal for a regulation aimed at establishing a common data platform on chemicals, based on the FAIR principle ( Findable, Accessible, Reusable, Interoperable). With the aim of ensuring the monitoring of these substances, adopting rapid alert systems when necessary, and increasing transparency for consumers on the evaluation and decision-making processes. (10)
The food sector would be included in the scope of the Regulation, and data on smoke flavourings should be included in the common platform. Access to all notified studies (under the Transparency Regulation) and data generated in new applications for authorization, renewals and other compliance could also support research and development of safe and sustainable products.
7) Provisional conclusions
The non-renewal of the authorization for the use of smoke flavorings is an important step in protecting the health of consumers, who can already now carefully read the ingredient list on food labels to avoid buying products that contain ‘smoke flavorings.
The retail and the industry could in turn reformulate as soon as possible numerous products which still contain these toxic chemicals, to confirm their social responsibility which goes beyond the generous concessions granted by Brussels to powerful lobbies.
Dario Dongo and Andrea Adelmo Della Penna
Footnotes
(1) A non-exhaustive list of raw materials is provided by the International Organization of Flavor Industry (IOFI). V. https://tinyurl.com/3xkwatsp
(2) EFSA FIP Panel (2021) Scientific Guidance for the preparation of applications on smoke flavoring primary products. EFSA Journal 19(3):e06345, https://doi.org/10.2903/j.efsa.2021.6435
(3) The categories indicated are those used for food additives. V. https://tinyurl.com/9fhkuskf
(4) EFFA statement about smoke flavoring primary products. European Flavor Association (EFFA). 5.8.24 https://tinyurl.com/yr3yexp2
(5) Court of Justice of the European Union (CJEU). Case T-523/24: Action brought on 10 October 2024 – Kerry and Kerry Ingredients (UK) v Commission http://data.europa.eu/eli/C/2025/83/oj
(6) Food Contaminants Regulation (EC) 1881/2006 was later repealed and replaced by the subsequent Regulation (EU) 2023/915
(7) A. Theobald, D. Arcella, A. Carere, C. Croera, K.-H. Engel, D. Gott, R. Gürtler, D. Meier, I. Pratt, IMCM Rietjens, R. Simon, R. Walker. Safety assessment of smoke flavoring primary products by the European Food Safety Authority. Trends in Food Science & Technology, Volume 27, Issue 2, 2012, Pages 97-108, ISSN 0924-2244, https://doi.org/10.1016/j.tifs.2012.06.002McDonald
(8) EFSA Scientific Committee; Scientific Opinion on genotoxicity testing strategies applicable to food and feed safety assessment. EFSA Journal 2011; 9(9):2379. [69 pp.] doi:10.2903/j.efsa.2011.2379
(9) EFSA Scientific Committee, More S, Bampidis V, Benford D, Boesten J, Bragard C, Halldorsson T, Hernandez-Jerez A, Hougaard-Bennekou S, Koutsoumanis K, Naegeli H, Nielsen SS, Schrenk D, Silano V, Turck D, Younes M, Aquilina G, Crebelli R, Gürtler R, Hirsch-Ernst KI, Mosesso P, Nielsen E, Solecki R, Carfì M, Martino C, Maurici D, Parra Morte J and Schlatter J, 2019. Statement on the genotoxicity assessment of chemical mixtures. EFSA Journal 2019;17(1):5519, 11 pp. https://doi.org/10.2903/j.efsa.2019.551
(10) Proposal for a Regulation of the European Parliament and of the Council establishing a common data platform on chemicals, laying down rules to ensure that the data contained therein are findable, accessible, interoperable and reusable and establishing a monitoring and outlook framework for chemicals (COM/2023/779 final) https://tinyurl.com/yuz5nr58
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.
