Mineral oil hydrocarbons (MOSH/MOAH)
A decision support project by the German Federal Ministry for Food and Agriculture (BMEL) in 2012 discovered a high potential for the migration of mineral oil hydrocarbons from recycled board into foodstuffs. However, mineral oil components can end up in foodstuffs in a range of different ways. Possible sources of contamination include:
- Packaging materials (recycled paper, ink, jute bags)
- Grease from harvesters and processing machines
- Exhaust fumes from the environment (compressed air)
- Dressings from corrugated cardboard containing mineral oil
- Food additives (separating agents, coating agents, brighteners, anti-dust agents)
What are MOSH and MOAH?
From a chemical point of view, mineral oils are complex compounds which are primarily composed of mineral oil saturated hydrocarbons (MOSH) and usually alkylated mineral oil aromatic hydrocarbons (MOAH). Both of these substance groups contain both linear, derived (i.e. annular) compounds of varying molecule size.
The material and percental composition of the individual mineral oil fractions can sometimes be very different depending on the origin and respective purpose of the mineral oils. For example, raw and technical mineral oils contain relatively high levels of MOAH, whereas refined medicinal mineral oils generally only contain traces or no detectable levels of aromatic components.
Moreover, certain marker substances such as diisopropylnaphthalene (DIPN) can indicate a contribution from recycled paper. By chemically characterising the mineral oil fractions using modern analytical methods such as two-dimensional gas chromatography paired with mass-selective detectors, GC×GC-MS therefore makes it possible to identify the source of contamination.
What are the health risks and the legal regulations?
According to the latest science, there is not enough toxicological evidence to prove a health risk to humans from saturated mineral oil fractions (MOSH). MOAHs, on the other hand, are suspected of having a carcinogenic effect (especially PAH-like compounds with three to seven ring systems), therefore their levels in foodstuffs should be kept to a minimum as per the ALARA principle (as low as reasonably achievable).
There are currently no specific legal regulations or maximum levels for mineral oil residues in foodstuffs. In February 2017 the fourth draft of the 22nd Ordinance on amending the German Consumer Goods Ordinance (‘Mineral oil ordinance’) was published. This stipulated that functional barriers should be used to ensure that MOAHs from materials containing recycled paper in contact with foodstuffs are not transferred to the foodstuff in detectable levels. The applicable detection limit is 0.5 mg/kg foodstuff. The draft is currently in consultation at the Federal Ministry and is due to be notified this year by the European Commission.
Comprehensive stage-by-stage controls can help identify and eliminate sources of contamination throughout the entire manufacturing and transport process. One way of reducing the contamination of foodstuffs is to use special barrier films, barrier layers or adsorber materials made from activated carbon incorporated into cardboard fibres. These can effectively minimise the migration of mineral oil hydrocarbons from food packaging as well as contamination from the environment.
How does the ifp carry out the analysis?
The ifp performs analyses using an HPLC-GC-FID method, which is based on the method of the German Federal Institute for Risk Assessment (BfR) of 2009 and DIN EN 16995. Various optimisation steps are undertaken to achieve a more advanced analytical evaluation.
The ifp offers the following services:
- Identification of contamination sources
- Planning of stage-by-stage controls
- Analysis of foodstuffs, lubricants, cardboard, plastics, etc. using web-linked, internally optimised HPLC-GC-FID
- Characterisation of mineral oil components in complex matrices by GC×GC-ToF
- Barrier testing