MOSH

Mineral oil saturated hydrocarbons (MOSH) are mineral oil-originated components. They are a complex mixture of several hundred thousand structurally similar hydrocarbons, that can have an open-chain or naphthenic structure, respectively. In terms of food contamination, MOSH with a chain length of between 10 and 50 carbon atoms is considered.

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From a toxicological perspective, EFSA concluded in its 2023 updated risk assessment [1] that MOSH in the molar mass range between C20 and C45 can accumulate in tissues, e.g. in the liver, fatty tissue or spleen. However, the risk of acute toxicity is currently considered to be minimal, as no critical effects could be clearly associated with the intake of MOSH during the animal studies carried out. Consequently, the EFSA concluted that exposure to MOSH currently does not pose a human health risk.

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At present, no officially authorised maximum levels for MOSH in food exist. As part of minimisation strategies, food control authorities and food associations provide a list of benchmark levels for relevant food categories, to be considered as an upper limit according to good manufacturing practice [2].

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Examples for MOSH bechmark levels in food (10/2024):

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• Vegetable oils and fats: 13 mg/kg

• Bread/cereal products: 6 mg/kg

• Confectionery/chocolate: 9 mg/kg

• Nuts, shell fruits, dried fruits: 4 mg/kg

• Meat, meat products: 9 mg/kg

• Fish, fish products: 4 mg/kg

• Milk, milk products: 22 mg/kg milk fat

• Vegan/vegetarian products: 5 - 11 mg/kg

MOAH

Mineral oil aromatic hydrocarbons (MOAH) are also mineral oil originated components analogous to MOSH. In contrast, however, these compounds are a mixture of highly alkylated aromatics with at least one aromatic ring system. In terms of food contaminantion, MOAH up to 7 rings is considered.

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From a toxicological point of view, the EFSA [1] subdivides MOAH into the 1-2 ring MOAH fraction and the 3-7 ring MOAH fraction. For 1-2 ring MOAH, toxicological data are still very limited, so human health concerns cannot be ruled out. For 3-7 ring MOAH, EFSA assesses the existing risk of carcinogenic effects due to the structural analogy to polycyclic aromatic hydrocarbons (PAHs). Consequently, EFSA concluded potential risk to human health for both MOAH subfractions.

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There are currently no authorised maximum levels for MOAH in food. However, in the context of the preventative principle, good manufacturing practice and risk minimisation, any positive analytical results for MOAH above the limit of quantification must currently be considered serious [2].

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The following benchmark levels for MOAH are currently to be taken into account as limits of quantification, depending on the foods fat content  (status 10/2024):

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• 0,5 mg/kg (food fat content  ≤ 4 %)

• 1,0 mg/kg (food fat content > 4 % und ≤ 50 %)

• 2,0 mg/kg (food fat content > 50 %).

Synthetic hydrocarbons

Polyolefin oligomers: The most commonly used polymers for food contact materials are polyolefins. In the past it has been shown that polyolefin oligomeric hydrocarbons (POH) migrate from the packaging into the food. These substances are composed of polyolefin oligomeric saturated hydrocarbons (POSH) and polyolefin oligomeric monounsaturated hydrocarbons (POMH).

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A toxicological evaluation of polyolefin oligomers is not yet available. However, most likely, an acute risk to the consumer cannot be assumed. Analytically, the presence of POSH can be reliably identified by HPLC-GC-FID and quantified by GCxGC-MS/FID.

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Resin oligomers: Various resins based on synthetic hydrocarbons are used as tackifiers in adhesives. When using hot-melts in cardboard folding boxes, studies have shown that resin oligomeric saturated hydrocarbons (ROSH) and resin oligomeric aromatic hydrocarbons (ROAH) migrate from the hot-melt to the packaged food via the gas phase. Analytically, the presence of ROSH/ROAH can usually be reliably identified by HPLC-GC-FID and quantified by GCxGC-MS/FID.

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Hydrogenated hydrocarbon resins (petroleum hydrocarbon resins, hydrogenated) are authroised as FCM No. 97 to be used in plastic materials and articles intended to come into contact with food by Commission Regulation (EU) No 10/2011 without a specific migration limit, which implies a low human health concern related to these substances.