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Abstract

In August 2023, 721 individuals became ill with gastrointestinal symptoms in 17 schools in a Finnish municipality. Of these, 323 (45%) developed quickly passing symptoms during school lunch or < 30 min after the lunch. In a questionnaire-based retrospective cohort study, consumption of flour tortillas and vegetable filling served at lunch were statistically associated with illness (adjusted odds ratio (aOR) = 3.3; 95% confidence interval (CI): 1.4–7.4 for the tortillas and aOR = 1.5; 95% CI: 1.1–2.1 for the filling). Abnormal odour was observed in five of nine tortilla samples. In three samples from tortillas produced during a limited production period, high concentrations of calcium propionate (E 282) were measured (> 24,000 mg/kg), exceeding the regulatory maximum limit of 2,000 mg/kg. The tortillas served at lunch were traced to a manufacturer in another EU country. The manufacturer was unable to identify any cause in the production process that could explain the high concentrations of calcium propionate. Our results are in line with findings from other investigations that excessive calcium propionate can induce gastrointestinal symptoms. The investigation highlights the need for strengthened surveillance of chemical-related food-borne outbreaks in Europe and timely communication between school staff and public health authorities to support rapid outbreak detection and response.

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2026-03-19
2026-04-13
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References

  1. Rather IA, Koh WY, Paek WK, Lim J. The sources of chemical contaminants in food and their health implications. Front Pharmacol. 2017;8:830.  https://doi.org/10.3389/fphar.2017.00830  PMID: 29204118 
  2. Balali-Mood M, Naseri K, Tahergorabi Z, Khazdair MR, Sadeghi M. Toxic mechanisms of five heavy metals: mercury, lead, chromium, cadmium, and arsenic. Front Pharmacol. 2021;12:643972.  https://doi.org/10.3389/fphar.2021.643972  PMID: 33927623 
  3. Pakdel M, Olsen A, Bar EMS. A review of food contaminants and their pathways within food processing facilities using open food processing equipment. J Food Prot. 2023;86(12):100184.  https://doi.org/10.1016/j.jfp.2023.100184  PMID: 37865163 
  4. Geueke B, Groh K, Muncke J. Food packaging in the circular economy: overview of chemical safety aspects for commonly used materials. J Clean Prod. 2018;193:491-505.  https://doi.org/10.1016/j.jclepro.2018.05.005 
  5. Dang L, Van Damme EJM. Toxic proteins in plants. Phytochemistry. 2015;117:51-64.  https://doi.org/10.1016/j.phytochem.2015.05.020  PMID: 26057229 
  6. European Food Safety Authority (EFSA)Carrasco Cabrera L, Di Piazza G, Dujardin B, Medina Pastor P. The 2021 European Union report on pesticide residues in food. EFSA J. 2023;21(4):e07939. PMID: 37122284 
  7. European Commission. Commission Regulation (EU) 2023/915 of 25 April 2023 on maximum levels for certain contaminants in food and repealing Regulation (EC) No 1881/2006. Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 5.5.2023: L 119. Available from: http://data.europa.eu/eli/reg/2023/915/2025-01-01
  8. European Commission. Regulation (EC) No 396/2005 of the European Parliament and of the Council of 23 February 2005 on maximum residue levels of pesticides in or on food and feed of plant and animal origin and amending Council Directive 91/414/EEC. Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 16.3.2005: L 70. Available from: http://data.europa.eu/eli/reg/2005/396/oj
  9. European Food Safety Authority (EFSA). Food additives. Parma: EFSA: 16 Feb 2026. Available from: https://www.efsa.europa.eu/en/topics/topic/food-additives
  10. European Commission. Regulation (EC) No 1333/2008 of the European Parliament and of the Council of 16 December 2008 on food additives. Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 31.12.2008: L 354. Available from: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333#d1e32-31-2
  11. European Commission. Commission Regulation (EU) No 231/2012 of 9 March 2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 of the European Parliament and of the Council. Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 22.3.2012: L: 83. Available from: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231
  12. Eskola M, Elliott CT, Hajšlová J, Steiner D, Krska R. Towards a dietary-exposome assessment of chemicals in food: An update on the chronic health risks for the European consumer. Crit Rev Food Sci Nutr. 2020;60(11):1890-911.  https://doi.org/10.1080/10408398.2019.1612320  PMID: 31094210 
  13. World Health Organization (WHO). Manual for investigating suspected outbreaks of illnesses of possible chemical etiology: guidance for investigation and control. Geneva: WHO; 2021. Available from: https://iris.who.int/bitstream/handle/10665/342818/9789240021754-eng.pdf?sequence=1
  14. European Court of Auditors (ECA). Special Report 2/2019: Chemical hazards in our food: EU food safety policy protects us but faces challenges. Luxembourg: ECA; 2019. Available from: https://op.europa.eu/webpub/eca/special-reports/food-safety-2-2019/en/index.html
  15. European Food Safety Authority (EFSA)Amore G, Boelaert F, Gibin D, Papanikolaou A, Rizzi V, et al. Zoonoses and foodborne outbreaks guidance for reporting 2021 data. EFSA Support Publ. 2022;19(1):EN-7131.
  16. Ministry for Foreign Affairs of Finland (UM) and Finnish National Agency for Education (EDUFI). School meals for all. Helsinki: UM and EDUFI; Jun 2019. Available from: https://um.fi/documents/35732/0/UM_CaseStudyFinland_SchoolFeeding_June2019_NETTI.pdf/5ae41e39-dec0-d8d1-90b4-baaa4a674350?t=1562652112088
  17. Finlex. Valtioneuvoston asetus elintarvikkeiden ja veden välityksellä leviävien epidemioiden selvittämisestä. [Regulation on investigations of food- and waterborne outbreaks]. Finlex. Helsinki: Finlex. 23.12.2011: 1365/2011. Finnish. Available from: https://www.finlex.fi/fi/laki/alkup/2011/20111365
  18. European Commission. Commission Regulation (EU) No. 2016/683 of 2 May 2016 amending Annex II to Regulation (EC) No 1333/2008 of the European Parliament and of the Council as regards the use of propionic acid — propionates (E 280-283) in tortillas. Official Journal of the European Union. Luxembourg: Publications Office of the European Union. 3.5.2016: L 117. Available from: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32016R0683
  19. National Center for Biotechnology Information (NCBI). Propionic acid. Bethesda: NCBI; 7 Mar 2026. Available from: https://pubchem.ncbi.nlm.nih.gov
  20. Centers for Disease Control and Prevention (CDC). Outbreaks of gastrointestinal illness of unknown etiology associated with eating burritos--United States, October 1997-October 1998. MMWR Morb Mortal Wkly Rep. 1999;48(10):210-3. PMID: 10099022 
  21. Steinberg EB, Henderson A, Karpati A, Hoekstra M, Marano N, Souza JM, et al. Mysterious outbreaks of gastrointestinal illness associated with burritos supplied through school lunch programs. J Food Prot. 2006;69(7):1690-8.  https://doi.org/10.4315/0362-028X-69.7.1690  PMID: 16865905 
  22. Centers for Disease Control and Prevention (CDC). Multiple outbreaks of gastrointestinal illness among school children associated with consumption of flour tortillas--Massachusetts, 2003-2004. MMWR Morb Mortal Wkly Rep. 2006;55(1):8-11. PMID: 16410761 
  23. EFSA Panel on Food additives and Nutrient Sources added to Food (ANS). Scientific Opinion on the re-evaluation of propionic acid (E 280), sodium propionate (E 281), calcium propionate (E 282) and potassium propionate (E 283) as food additives. EFSA J. 2014;12(7):3779.  https://doi.org/10.2903/j.efsa.2014.3779 
  24. EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP). Scientific Opinion on the safety and efficacy of propionic acid, sodium propionate, calcium propionate and ammonium propionate for all animal species. EFSA J. 2011;9(12):2446.  https://doi.org/10.2903/j.efsa.2011.2446 
  25. Food and Drug Administration (FDA). Code of Federal Regulations, Title 21. § 184.1221. Calcium propionate. FDA: Silver Spring; 10 Mar 2026. Available from: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-184/subpart-B/section-184.1221
  26. Jacks A, Toikkanen S, Pihlajasaari A, Johansson T, Hakkinen M, Hemminki K, et al. Raw grated beetroot linked to several outbreaks of sudden-onset gastrointestinal illness, Finland 2010. Epidemiol Infect. 2013;141(8):1640-6.  https://doi.org/10.1017/S0950268812002233  PMID: 23068603 
  27. Nerín C, Aznar M, Carrizo D. Food contamination during food process. Trends Food Sci Technol. 2016;48:63-8.  https://doi.org/10.1016/j.tifs.2015.12.004 
  28. Bennett SD, Walsh KA, Gould LH. Foodborne disease outbreaks caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus--United States, 1998-2008. Clin Infect Dis. 2013;57(3):425-33.  https://doi.org/10.1093/cid/cit244  PMID: 23592829 
  29. Ehling-Schulz M, Fricker M, Scherer S. Bacillus cereus, the causative agent of an emetic type of food-borne illness. Mol Nutr Food Res. 2004;48(7):479-87.  https://doi.org/10.1002/mnfr.200400055  PMID: 15538709 
  30. Lebelo K, Malebo N, Mochane MJ, Masinde M. Chemical contamination pathways and the food safety implications along the various stages of food production: a review. Int J Environ Res Public Health. 2021;18(11):5795.  https://doi.org/10.3390/ijerph18115795  PMID: 34071295 
  31. Lupcho T, Harrist A, Van Houten C. Gastrointestinal illness associated with rancid tortilla chips at a correctional facility - Wyoming, 2015. MMWR Morb Mortal Wkly Rep. 2016;65(42):1170-3.  https://doi.org/10.15585/mmwr.mm6542a4  PMID: 27787491 
  32. Bhat RV, Vemula SR, Pokkunuri Y, Siddula G, Purnachandra GK. Foodborne disease outbreak due to consumption of rancid biscuits. J Toxicol Clin Toxicol. 1995;33(3):219-22.  https://doi.org/10.3109/15563659509017987  PMID: 7760445 
  33. McClements DJ, Decker EA. Lipids. In: Damodaran S, Parkin KL (editors). Fennema’s Food Chemistry. Boca Raton: Taylor & Francis Group; 2017. p. 171-234. Available from: https://www.taylorfrancis.com/books/edit/10.1201/9781315372914/fennema-food-chemistry-srinivasan-damodaran-kirk-parkin
  34. Jacobson MF, DePorter J. Self-reported adverse reactions associated with mycoprotein (Quorn-brand) containing foods. Ann Allergy Asthma Immunol. 2018;120(6):626-30.  https://doi.org/10.1016/j.anai.2018.03.020  PMID: 29567357 
  35. Watier-Grillot S, Larréché S, Mazuet C, Baudouin F, Feraudet-Tarisse C, Holterbach L, et al. From foodborne disease outbreak (FBDO) to investigation: the plant toxin trap, Brittany, France, 2018. Toxins (Basel). 2023;15(7):457.  https://doi.org/10.3390/toxins15070457  PMID: 37505726 
  36. Rodhouse JC, Haugh CA, Roberts D, Gilbert RJ. Red kidney bean poisoning in the UK: an analysis of 50 suspected incidents between 1976 and 1989. Epidemiol Infect. 1990;105(3):485-91.  https://doi.org/10.1017/S095026880004810X  PMID: 2249712 
  37. Hammer GP, du Prel JB, Blettner M. Avoiding bias in observational studies: part 8 in a series of articles on evaluation of scientific publications. Dtsch Arztebl Int. 2009;106(41):664-8. PMID: 19946431 
Calcium propionate in tortillas – a likely cause of a large outbreak of acute gastrointestinal illness, Finland, 2023
<p class="citation"> <span>Citation style for this article:</span> <span class="meta-value authors"> <a href="/search?value1=Veera+Varo&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Varo Veera</a>, <a href="/search?value1=Elina+Leinonen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Leinonen Elina</a>, <a href="/search?value1=Annukka+Markkula&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Markkula Annukka</a>, <a href="/search?value1=Minna+Anthoni&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Anthoni Minna</a>, <a href="/search?value1=Marja+Raatikainen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Raatikainen Marja</a>, <a href="/search?value1=Maria+Tirkkonen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Tirkkonen Maria</a>, <a href="/search?value1=Nina+Gynther&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Gynther Nina</a>, <a href="/search?value1=Heidi+Landgren&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Landgren Heidi</a>, <a href="/search?value1=Merja+Korkalainen&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Korkalainen Merja</a>, <a href="/search?value1=Ruska+Rimhanen-Finne&option1=author&noRedirect=true" class="nonDisambigAuthorLink">Rimhanen-Finne Ruska</a></span>. Calcium propionate in tortillas – a likely cause of a large outbreak of acute gastrointestinal illness, Finland, 2023. <a href="/content/ecdc">Euro Surveill.</a> 2026;31(11):pii=2500507. <a href="https://doi.org/10.2807/1560-7917.ES.2026.31.11.2600185" title="doi link" target="_blank">https://doi.org/10.2807/1560-7917.ES.2026.31.11.2600185</a> <span class="ES_Article_citation"> <span class="generated">Received</span>: 04 Jul 2025;&nbsp;&nbsp; <span class="generated">Accepted</span>: 22 Oct 2025 </span> </p>
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