MOSH MOAH Reduction of Mineral Oil Contamination in Food

In the field of mineral oil contamination, significant progress has been made in recent years. Numerous sources of contamination throughout the production process have been identified, and the initial, often high levels (up to several grams per kilogram) in food have been reduced to just a few milligrams. In analytical chemistry, standardized methods with appropriate detection sensitivity have been developed. 

Until now, however, it has been challenging to deduce potential health hazards from detected mineral oil contamination. Within the framework of this project, a comprehensive characterization using chemical analysis was combined with toxicological tests of the identified fractions for the first time. It was demonstrated that only certain aromatic mineral oil fractions - those containing three or more aromatic rings - exhibit mutagenic potential. This allows for a much more differentiated assessment of detected mineral oil contamination in food. During a screening of various machine oils, identified by industry partners in this project as posing a real contamination risk to food, it was shown that none of these oils needed to be classified as critical, as no DNA-reactive, mutagenic MOAH fractions could be detected. 

The publication [1] resulting from this project has already been cited in regulatory contexts. It serves as a reference in both the current EFSA opinion [2] and a guideline from the Joint Research Centre (JRC) of the European Commission [3], demonstrating that, in mineral oil contamination, specific fractions are of high toxicological relevance. Non-Aromatic, saturated mineral oil fractions (MOSH) were classified as harmless in EFSA's reassessment. For the carcinogenic MOAH, threshold values have been established for the first time. 

The Austrian project "MOSH MOAH - Reduction of Mineral Oil in Food" has actively contributed to finding solutions to the issue of mineral oil residues in food across the entire production chain. The goal of this project was to typify the sources of MOSH and MOAH contamination in food, develop and improve detection methods, assess the genotoxic potential of the typified compounds, and formulate recommendations and guidelines for handling MOSH/MOAH. 

The objectives were successfully achieved. 

Highlights:

  • Sample Preparation Procedures: Methods for routine processing of many matrices were developed and, in effective collaboration with the scientific community and public authorities, brought to the level of validated and stanardized procedures. 
  • Chromatographic Methods: The suitability of GCxGC-ToF as an advanced chromatographic method for routine application in verifying and characterizing samples, as well as assessing genotoxic potential, was demonstrated. "Best-Practice" guidelines were drafted and made available to the relevant community. 
  • MOAH Fraction Identification: High-purity MOAH fractions and sub-fractions were identified and separated from mineral oil and food contact materials. These were used to evaluate the genotoxic hazard potential of the fractions and sub-fractions, categorized by the number of aromatic rings, using the AMES test, correlating the results with substance groups identified through chemical analysis. 
  • Method Validation: The combined method of AMES test and chemical analysis developed for assessing genotoxicity in positive MOAH findings was validated. 
  • Scientific Contribution: The publication resulting from this project was incorporated into a current guideline by the Joint Research Centre of the European Commission and an EFSA opinion, providing scientific evidence that only specific mineral oil fractions are of high toxicological importance. 

References:

[1] Hochegger A, Wagenhofer R, Savić S, Mayrhofer E, Washüttl M, Leitner E. Combination of Multidimensional Instrumental Analysis and the Ames Test for the Toxicological Evaluation of Mineral Oil Aromatic Hydrocarbons. J Agric Food Chem. 2022; https://doi.org/10.1021/acs.jafc.2c05970

[2] EFSA Panel on Contaminants in the Food Chain (CONTAM), Dieter Schrenk, Margherita Bignami, Laurent Bodin, James Kevin Chipman, Jesús del Mazo, Bettina Grasl-Kraupp, Christer Hogstrand, Laurentius (Ron) Hoogenboom, Jean-Charles Leblanc, Carlo Stefano Nebbia, Elsa Nielsen, Evangelia Ntzani, Annette Petersen, Salomon Sand, Tanja Schwerdtle, Christiane Vleminckx, Heather Wallace, José Angel Gomez Ruiz, Olaf Mosbach-Schulz, Marco Binaglia and James Kevin Chipman. Update of the risk assessment of mineral oil hydrocarbons (MOH) in food -Draft; 2023.

[3] European Commission. Joint Research Centre. Determination of MOSH and MOAH in edible oil: proficiency test report JRC FCM 22/01: Publications Office; 2023.

Follow this link to read more about the project's findings.