2.7. Mineral Oil Hydrocarbons (last update: February 2026)

Cocoa products, in common with many other foods, could potentially be exposed to mineral oil hydrocarbons (MOH) at various points in the chain from the farm to the consumer, since they are found in various packaging materials and food additives and arise from contamination by lubricants, fuels, and debris from tyres and road bitumen too (Figure 5).

The term MOH summarizes two groups; mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH). In 2023, EFSA published an update to its scientific opinion on MOH in which it provisionally concluded that dietary exposure to MOSH does not raise concern for human health, though it recommends that potential long term effects continue to be investigated (EFSA, 2023). However, concerns remain regarding the potential carcinogenicity and genotoxicity of MOAH, specifically related to 3 or more aromatic rings, with a lack of toxicological information on the effects of 1-2 ring MOAH. The scientific opinion has also clearly defined substances which are considered part of the MOH group and substances which are not.

Although a new EU regulation on MOAH levels in foods is expected to be published in 2026, with limits coming into force in 2027, as an interim measure the EU Member States drafted a joint statement regarding the presence of MOAH in food in April 2022 (with clarification in October 2022) (see SCoPAFF, 2022). 

This proposes a uniform enforcement approach which will remain in force until maximum levels are established following the publication of the new regulation:

“The Member States agreed to withdraw and, if necessary, to recall products from the market, when the sum of the concentrations of MOAH in food are at or above the following maximum LOQs” 

• 0.5 mg/kg for dry foods with a low fat/oil content (≤ 4% fat/oil)
• 1 mg/kg for foods with a higher fat/oil content (> 4% fat/oil, ≤ 50% fat/oil)
• 2 mg/kg for fats/ oils or foods with > 50% fat/oil

Moreover, representatives of the German Food Control Authorities and Food Federation Germany have recommended benchmark limits for MOH based on monitoring data collected from an extensive range of sources and investigations on the sources of MOH contamination through food supply chains. The benchmarks set for chocolate and cocoa-based confectionery were set at 9 mg/kg for MOSH and its analogues (C10-C50) [1], but at “not quantifiable” (levels as per EU statement above) for the MOAH due to their potential carcinogenic /genotoxic nature (see LAV/Lebensmittelverband, 2022).

Since the effects of MOAH on human health continue to be investigated and the analytical methodology for MOH continue to be refined, reference to the EFSA and EU Joint Research Centre websites for the latest information is recommended. There are a number of approaches which can be taken to minimize MOH contamination in cocoa products and these were investigated in projects supported by the BDSI and Foundation of the German Cocoa and Chocolate Industry (BDSI Toolbox MOSH_MOAH) (see Matissek, 2014; Matissek, Raters, Dingel, & Schnapka, 2014; Schnapka et al. 2022) and the CAOBISCO-ECA Joint Cocoa Research Fund (see JRF MOH study).

Cocoa beans might be exposed to MOH contamination during drying, particularly from fuel or fumes from oil fired burners when cocoa beans are dried artificially in direct dryers (i.e. those without gas/air heat exchangers), or from exhaust fumes and debris if they are dried close to roads (see 2.8 PAH and Part III 3.b drying). 

Cocoa beans and cocoa products may also be contaminated by fuels and lubricants used on machinery and from packaging materials during transportation and storage (see Part III Storage and Part III Transportation and Shipping) and also by technical equipment during processing to cocoa butter and other products. 

Recycled cardboard packaging, including the dressings used to line containers for shipping, may be contaminated by mineral oil-based printing inks from the recycled paper used to produce it. Such inks would also be a potential source of contamination if used on jute bags.
 

Jute Bags

Another important source of contamination can be jute sacks manufactured using fibres which have been processed (batched) using mineral oils rather than vegetable oils. Laboratory tests have shown that MOH can migrate from contaminated jute onto the shell of the cocoa beans, and eventually to the cocoa nib. Higher levels of contamination are associated with broken beans where the shell is damaged and no longer able to act as a barrier to migration. Although the use of mineral oils in the manufacture of sacks sent to Europe was largely stopped in the late 1990s, they are widely used elsewhere. In 1998, the International Jute Organisation (IJO) adopted ‘special criteria for the manufacture of jute bags used in the packaging of selected foods (cocoa beans, coffee beans and shelled nuts)’ (IJO98/01). The batching oil shall only contain non-toxic ingredients and it shall not contain compounds that produce off-flavours or off-tastes in food.

The IJO98/01 also specifies limits for the presence of unsaponifiable material in the bags (less than 1250 mg/kg jute fibre) as a proxy for mineral oil hydrocarbons. This limit was adopted by the ICCO in March 1999 and it was stated that the methods to be adopted in determining the limits were to follow British Standard 3845:1990 on methods for the determination of added oil content of jute yarn, rove and fabric (with subsequent saponification using the methodology described in WG 1/90 of the International Union of Pure and Applied Chemistry (IUPAC). Further, the organoleptic properties of the bags were included such that no undesirable odours or odours untypical of jute shall be present. No unacceptable odours shall develop after artificial ageing of the bags. The ageing procedure to be followed shall be the one described in European Standard EN 766 on bags for the transport of food aid.

Despite all the measures taken, the sector still faces challenges with mineral oil contamination originating from jute bags as indicated by the results from the JRF MOH study [click here for summary].

As a response, a MOH Technical Working Group (MOH TWG), involving representatives from the cocoa and confectionery industry, FCC, ICCO, trade organisations, jute bag manufacturers, and authorities from jute producing countries was established in 2022 to address the challenge that jute bag-derived MOH contamination poses to the cocoa industry.

The MOH TWG supported a further research project to gain an insight into the causes of variability of levels of MOH contamination in jute bags, assess entry points of contamination, determine if the IJO98/01 is adequate to prevent the use of MOSH/MOAH contaminated jute bags in the cocoa supply chain and, if not, to propose new specifications that will help minimise the risk that cocoa products will not meet the anticipated EU limits due to contamination arising from contact with jute packaging [click here for summary]. It was found that MOSH/MOAH contamination is still a problem even in bags which conform to IJO98/01, with indications that printing inks, lubricants and cross-contamination from mineral-oil batched jute produced in the same factory are likely contributing factors. It is clear that reliane on the IJO98/01 criteria cannot provide assurance that bags are contaminated, especially with regards to MOAH, and a new standard based on analysis of MOSH/MOAH levels is urgently needed for jute for use in the cocoa supply chain. As an interim measure, the MOH TWG has advocated an industry specification (see below) as part of a roadmap to prevent MOH contamination.

Click here for further sources of information.