Mineral oil hydrocarbons
Mineral oil hydrocarbons (MOH) are complex mixtures with widely varying compositions that occur in saturated (MOSH - mineral oil saturated hydrocarbons) and aromatic form (MOAH - mineral oil aromatic hydrocarbons). They are mainly derived from petroleum/products and to a lesser extent from coal, natural gas and biomass, for example.
Mineral oil hydrocarbons can enter food either through intentional, targeted use or unintentionally. The most important sources of entry include, for example:
- Packaging materials and transport materials along the value chain such as
- Recycled packaging made from waste paper due to the mineral oil-containing printing inks. These cannot be sufficiently removed during the recycling process and can get onto the food in case of direct contact.
- Treated raw material packaging such as jute sacks
- Food grade ("food grade") lubricants and technical lubricants
- Additives and technical aids such as release agents, brighteners and lubricants
- Crop protection agents such as kerosene
- Veterinary medicines
- Hygiene products such as lotions, lipsticks and hair products
- Medical products
Since petroleum hydrocarbons enter raw food products through environmental contamination due to various factors such as emissions, oil vapors/mist, combustion gases/exhaust fumes, particulate matter and soot from the surrounding environment (e.g., via agricultural operations, transportation operations, storage or processing operations), contamination (contamination) is unavoidable.
The health effects of petroleum hydrocarbon contamination vary widely because it is a mixture of many different substances with varying hazard potential. The focus of the risk assessment is on identifying polycyclic aromatic hydrocarbon compounds that are frequently carcinogenic (these are among the MOAH) and shorter-chain saturated hydrocarbons (part of the MOSH) that accumulate in tissues. In its re-evaluation of MOSHs and MOAHs published in September 2023, the European Food Safety Authority (EFSA) concluded the following:
In the case of MOSH, based on the scientific studies currently available, there is a high probability that no adverse health effects are expected in humans. The underlying scientific studies suggest that observed adverse effects on the liver, which have been shown in a specific strain of rats, are not relevant for humans. Nevertheless, it is important to further investigate the potential long-term effects on human health.
In the case of MOAHs with 3 or more aromatic rings, on the other hand, negative health effects cannot be excluded, especially in young children but also in the rest of the population, due to their possible carcinogenic and mutagenic effects. However, further toxicological data as well as data related to the intake of MOAH by the population are needed for a final risk assessment.
In the case of MOAH with 1-2 aromatic rings, which may also have adverse health effects, there are currently insufficient toxicological data for a risk assessment of these compounds.
Situation in Austria
The following temporary harmonized action levels have been agreed at EU level:
- 0.5 mg/kg for dry foods with a low fat/oil content (below 4 % fat/oil)
- 1 mg/kg for foods with a higher fat/oil content (above 4 %fat/oil, below 50 %fat/oil )
- 2 mg/kg for fats/oils or foods with a fat/oil content above 50% .
These are currently the lowest levels that can be determined with appropriate reliability by laboratories in the EU.
To prevent mineral oil hydrocarbons from entering foodstuffs in food packaging made from recycled cardboard, measures exist such as the use of barrier layers( e.g. plastic film) or adsorbent substances( e.g. activated carbon). The requirements to be considered in this regard can be found in the current Council of Europe Resolution and Technical Guideline(https://freepub.edqm.eu/publications/PUBSD-115/detail) Paper and Board used in food contact materials and articles, EDQM 2021). There is also an Austrian recommendation on the use of recycled board for food packaging(BMG-75210/0018-II/B/13/2012 of 21.12.2012).
In 2017, the German Food Association developed a "Toolbox for the prevention of inputs of undesirable mineral oil hydrocarbons into food". The aim of this toolbox is to control the risk of avoidable mineral oil inputs along the value chain as far as possible through stage-related analyses and to identify approaches to reduce the input quantities.
We investigate food products for mineral oil hydrocarbons as part of focus actions. In 2017, we investigated 20 carton-packed food products for MOSH and MOAH contamination. Both MOAH and MOSH were detected in all carton samples tested(MOAH: 8 - 318 mg/kg; MOSH: 21 - 1213 mg/kg material).
As part of an investigation of bread, cookies, breakfast cereals, canned fish and sausages in 2019, we carried out a determination of MOH in 52 samples. This showed that MOSH was detectable in only three samples and MOAH in one of the samples.
In 2022, we tested 20 samples of infant formula and follow-on formula for mineral oil hydrocarbons as part of a focus action. MOSH was detected in all samples, with the majority located at MOSH with a chain length of C25 or greater, while MOAH was not detected in quantifiable amounts in any of the samples. None of the available samples was objectionable on the basis of the assessment principles.
MOH can be divided into three main groups:
- straight and branched chain open alkanes (kerosenes)
- (mostly) alkylated cycloalkanes (naphthenes)
- alkylated and non-alkylated aromatics.
While the first two groups belong to the MOSH (mineral oil saturated hydrocarbons), the non-alkylated aromatic compounds belong to the MOAH (mineral oil aromatic hydrocarbons).
The usual ratio of MOSH:MOAH is 4:1.
In addition, there are MOSH analogs such as mineral oil refined products(MORE - Mineral Oil Refined Products), polyalphaolefins (PAO) and oligomers from the plastics polyethylene or polypropylene(POSH - Polymer Oligomeric Saturated Hydrocarbons).
An analytical differentiation of MOSH and MOSH analogues is not always possible with the currently established methods. Therefore, the presence of MOSH analogs leads to an increase in MOSH readings, shifting the usual ratio of MOSH and MOAH. Also, some plants naturally contain hydrocarbon compounds (plant waxes, biogenic waxes, terpenes, olefins, etc.) that are very similar to MOSH compounds in chemical structure. Natural olefins, terpenes and carotenoids can increase the measured MOAH level. Due to the complexity of MOH mixtures, it is not possible to analyze the individual components using currently established methods.
Animal studies have shown that MOSH can accumulate in tissues and lead to inflammatory reactions in the liver. In organs of rats (liver, spleen), MOSH could be detected and quantified up to a carbon chain of C45. MOSH have also been detected in human tissues, but MOSH with a carbon chain length below C16 do not accumulate in the human body. The health relevance for humans has not yet been conclusively clarified.
Improvements in the analysis and corresponding risk assessments of these substances are currently being worked on throughout Europe. However, this also requires relevant toxicological studies.
EFSA assessment of mineral oil hydrocarbons (MOSH and MOAH) from 2012
A study published in 2012 by the European Food Safety Authority(EFSA) found that people ingest between 0.03 mg and 0.3 mg of saturated petroleum hydrocarbons(MOSHs ) per kilogram of body weight per day through food. Infants and children have the highest intake levels within the population, at 0.2-0.3 mg MOSH per kg body weight. Among toddlers and children, ice cream and desserts are the main contributors to the intake of mineral oil from food. Furthermore, EFSA's findings showed that the intake of aromatic hydrocarbons(MOAH) is about 20 percent of the levels for MOSH, i.e. between 0.006 and 0.06 mg/kilogram body weight per day.
The health relevance of MOSH compounds for humans has not yet been conclusively determined. In the absence of toxicological data, EFSA concluded in the case of MOAH compounds that the detection of MOAH in food should be considered of potential concern for human health.
EFSA's 2019 assessment of MOAH.
In its 2019 risk assessment of MOAH contamination in infant formula and follow-on formula, EFSA concluded that MOAH are present at concentrations of 0.9 to 3.5 mg/kg in these products and due to the possible presence of 3-7 PAH compounds in MOAH, should be considered a health concern.
EFSA assessment of petroleum hydrocarbons (MOSH and MOAH) from 2023.
EFSA's re-evaluation of MOSH and MOAH compounds, published in September 2023, considered new toxicity studies as well as occurrence data published or submitted since EFSA's report published in 2012.
The following summarizes the results of EFSA's re-evaluation of MOSHs and MOAHs.
Recent evidence suggests that tissue changes (microgranuloma) and inflammation in the liver (=most relevant endpoint in animal studies) are specific to rat strain F344 and are not relevant to humans. Other relevant health effects related to human ingestion of MOSH compounds were also not identified.
The recalculated exposure of 0.009 to 0.212 mg MOSH/kg bw/day is lower than the calculated exposure in the 2012 report. For infants fed infant formula, an exposure of 0.22 to 0.37 mg MOSH/kg bw/day was calculated.
In summary, the risk characterization concluded that, based on the available data, adverse health effects to humans are unlikely with respect to MOSH compounds.
MOAH compounds with 3 or more rings were, as I have done in previous reports, classified as a health concern due to a possible mutagenic and carcinogenic effect, in particular due to their similarity to polycyclic aromatic hydrocarbons (PAHs). With regard to MOAH compounds with 1 to 2 rings, there is still only limited information available.
The calculated exposure of the total population was 0.003 to 0.059 mg MOAH/kg bw/day. For infants fed infant formula, exposure was calculated to be 0.019 to 0.063 mg MOAH/kg bw/day. It is assumed that this includes mainly MOAH with 1 to 2 rings and only a small proportion of the more harmful MOAH compounds with 3 or more rings. The exact proportions are currently not known.
For MOAH compounds with 3 or more rings, the reference point of 0.49 mg/kg bw/day was used due to their similarity to PAHs. The risk characterization showed that MOAH compounds with 3 or more rings in food should be considered as a health concern.
In the case of MOAH compounds with 1 or 2 rings, no reference point could be derived due to lack of toxicological data. Exposure to MOAH compounds with 1 to 2 rings in food is considered to be of potential concern according to EFSA.
European Food Safety Authority (EFSA) 2019: Rapid risk assessment on the possible risk for public health due to the contamination of infant formula and follow-on formula by mineral oil aromatic hydrocarbons (MOAH). EFSA Supporting publication 2019:EN-1741.
European Commission 2022. Clarifications on the joint statement of 21 April 2022 of the Member States regarding the presence of Mineral Oil Aromatic Hydrocarbons (MOAH) in food, including food for infants and young children.
S. Bratinova, E. Hoekstra (Editors) 2019. guidance on sampling, analysis and data reporting for the monitoring of mineral oil hydrocarbons in food and food contact materials, Luxembourg: Publications Office of the European Union, 2019 ISBN 978-92-76-00172-0, doi:10.2760/208879, JRC115694.
Last updated: 21.09.2023