Mineral oil hydrocarbons: EFSA publishes opinion on these complex compounds

The European Food Safety Authority (EFSA) has published a scientific opinion on human exposure through the diet to a diverse group of mixtures known as ‘mineral oil hydrocarbons’ (MOH). The potential human health impact of MOH varies widely; so-called ‘aromatic’ MOH may act as genotoxic carcinogens (that is they may damage DNA, the genetic material of cells, as well as cause cancer), while some ‘saturated’ MOH can accumulate in human tissue and may cause adverse effects in the liver. The opinion identifies some potential concerns in relation to exposure to MOH through food. However, EFSA’s experts stress there are several uncertainties regarding the chemical composition of MOH mixtures to which humans are exposed and also the wide range of sources of human exposure. Furthermore, on the basis of new information on the lack of toxicological relevance for humans of previous animal studies, the temporary Acceptable Daily Intakes (ADIs) of some ‘saturated’ MOH present in specific food products warrant revision.

MOH comprise a diverse group of mixtures of hydrocarbons containing thousands of chemical compounds of different structures and size, derived mainly from crude oil but also produced synthetically from coal, natural gas and biomass. The chemical composition of most MOH mixtures is unknown and usually varies from batch to batch; specifications are often expressed in terms of viscosity, or ‘thickness’, as related to the applications of the products and not in terms of chemical composition. These highly complex mixtures have a wide variety of industrial and domestic uses. There are several possible sources of MOH in food: mainly food packaging materials, food additives, processing aids and environmental contaminants such as lubricants.

Experts on EFSA’s Panel on Contaminants in the Food Chain (CONTAM) identified two main types of MOH relevant for food safety: saturated and aromatic hydrocarbons. The CONTAM Panel carried out an assessment of consumer exposure to MOH, including ‘background’ or low-level presence in food. From the available data, low levels of saturated MOH were present in all the food groups included with some high levels found in ‘Bread and rolls’ and ‘Grains for human consumption’ due to their use, respectively, as release/non-sticking agents and spraying agents (used to make grains shiny). The presence of both saturated and aromatic MOH (though data are more limited for the latter) in dry foods including ‘pudding’ dessert mixes and noodles may be partially attributed to the use of recycled paper/cardboard packaging. Exposure to saturated MOH through the diet was higher among younger consumers than for adults and the elderly.

In terms of the risk associated with exposure to MOH in food, the CONTAM Panel concluded there may be a potential concern for some consumers: specifically, customers who are brand loyal or who often buy the same food product from the same shop may be exposed on a regular basis to food with higher levels of MOH.

Although the establishment of new health-based guidance values for MOH products used as food additives was outside the scope of this opinion, the CONTAM Panel concluded that the opinion provides a suitable basis for revising the temporary group ADI of some low- and medium-viscosity MOH intended for food use. These MOH products were evaluated by the former Scientific Committee on Food (SCF) and by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and are currently being reviewed by JECFA. Recent information considered for this opinion indicated that the accumulation of saturated MOH in the lymph nodes found in the gut of laboratory animals is less relevant for human health than was thought at the time this temporary group ADI was set. The CONTAM Panel considers the revision of the ADIs for high-viscosity MOH a low priority.

With regard to the risk associated with exposure to aromatic MOH, which are both genotoxic and carcinogenic, the CONTAM Panel was not able to express this in quantitative terms because of insufficient information both on exposure and toxicology. In view of the carcinogenic properties of this type of MOH the Panel considered exposure to this type of MOH as being of potential concern.

EFSA’s opinion also makes a series of recommendations for improving methods of analysis and data collection and monitoring, as well as indications for possible future priorities of scientific research on MOH.

EFSA’s Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids provided support for the sections of the opinion dealing with the presence of MOH in food contact materials and exposure from foods packed in recycled paper.

• Scientific Opinion on Mineral Oil Hydrocarbons in Food