Mineral oil hydrocarbons
Mineral oils are comprised of various hydrocarbons. If these are aliphatic, i.e. come in the form of saturated linear and cyclic (non-aromatic) hydrocarbons with mostly 16 – 25 carbon atoms, these are referred to as “mineral oil saturated hydrocarbons” (MOSH). Aromatic, i.e. unsaturated hydrocarbons consist of mostly alkylated polycyclic compounds (usually with 1 – 4 aromatic rings) and are referred to as “mineral oil aromatic hydrocarbons" (MOAH).
How does mineral oil get into food packaging?
Mineral oil saturated hydrocarbons are predominately used as solvents. They are contained in heating oils, lubricants and motor fuels, but also in many printing inks as used for newspapers, for example. When producing cardboard boxes from recycled recovered paper, mineral oil saturated hydrocarbons get into the food packaging. It is currently not possible to eliminate a sufficient quantity of these substances during the recycling process. Mineral oils may also be found in inks and colours used for printing food packaging. Contamination from packed raw materials (e.g. printed jute bags) cannot be ruled out either. With mainly dry food with a large surface area being packed in cardboard boxes, the volatile mineral oils find their way into the food by gas phase diffusion.
What effects do mineral oils have on human health?
Mineral oil saturated hydrocarbons (MOSH) are absorbed by the body and stored in various organs. Animal testing has shown that this kind of mineral oil mixtures is deposited in the body and may cause damage to the liver and the lymph nodes. The exact composition of the mixtures in printer’s ink, especially of the fraction that contains aromatic hydrocarbons (MOAH), is not known.
There is currently no toxicological data for the evaluation and derivation of limit values for MOAH. The opinion of the Federal Institute for Risk Assessment (BfR), stating the potentially carcinogenic effect of the aromatic hydrocarbon fraction, was confirmed this year by the European Food Safety Authority (EFSA). For this reason no detectable migration of MOAH to food should be allowed to take place.
The data required for the evaluation of MOSH in the molecular weight range after migration from recycled cardboard is currently insufficient. The joint FAO/WHO Expert Committee on Food Additives (JECFA) has therefore withdrawn the temporary ADI (acceptable daily intake) this year. An ADI value specifies the amount of a substance a person can ingest each day for their entire life without needing to expect a hazard to health. The BfR has concluded a guide value for migration to foodstuffs of 12 mg/kg for MOSH with hydrocarbon chain lengths of C10 to C16. Currently a guide value for MOSH up to C20 is being discussed. There is evidence that MOSH with larger chain lengths is deposited in the human body. Migration of these substances should therefore be minimised as much as technically possible.
The European Food Safety Authority (EFSA) has estimated that we ingest between 0.03 and 0.3 mg saturated hydrocarbons (MOSH) per kilogramme of body weight with our daily food, children may ingest even more. The intake of aromatic hydrocarbons (MOAH) is estimated by the EFSA to be around 20% of the values for MOSH, i.e. between 0.005 and 0.06 mg per kilogramme of body weight. For a child weighing 10 kg this implies a daily intake of up to 3 mg MOSH and 0.6 mg MOAH.
Analysis of MOSH and MOAH
For analysis of MOSH and MOAH, the extract is purified by means of normal phase HPLC and determined by GC/FID.