Following a request from the European Commission, the Panel on Food Additives and Nutrient Sources added to Food (ANS) was asked to deliver a scientific opinion on the safety of medium viscosity white mineral oil (MVMO) with a kinematic viscosity between 8.5 – 11 mm2/s at 100 °C as food additive.
In 1995, the Scientific Committee for Food (SCF) allocated a temporary group acceptable daily intake (ADI) of 0-4 mg/kg bw/day for white paraffinic mineral oils derived from petroleum based hydrocarbons feed stocks (kinematic viscosity not less than 8.5 mm2/s at 100 °C; carbon number, not less than 25 at the 5 % boiling point; average molecular weight not less than 480 g/mol).
In 2002, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) re-evaluated several types of mineral oils, including class I medium- and low-viscosity mineral oil. In a 2-year feeding study in the rat (male and female) at doses between 60 and 1200 mg/kg bw/day, some effects were observed but JECFA considered that these effects were indicators of exposure to mineral hydrocarbons rather than adverse effects. Based on the results of the 2-year study, JECFA allocated an ADI of 0-10 mg/kg bw/day.
In 2009, the ANS Panel evaluated the high viscosity white mineral oil (HVMO) with a kinematic viscosity ≥11 mm2/s at 100 °C, a carbon number >28 at 5 % distillation point and an average molecular weight >500 g/mol). In this evaluation the ANS Panel considered a study by Trimmer (Trimmer, 2001; Trimmer et al., 2004) as pivotal. The 2-year study in rats (male and female) assessed the chronic toxicity and carcinogenicity of two mineral oils: a MVMO (kinematic medium 8.97 mm2/s at 100 °C) and a HVMO (kinematic viscosity 11 mm2/s at 100 °C). The MVMO used in the Trimmer study is representative for the type of white mineral oil evaluated in the present opinion.
The study was conducted in compliance with OECD guidelines for chronic toxicity/carcinogenicity (OECD 453) and GLP principles. It consisted of three phases: a chronic toxicity phase, a carcinogenicity phase and a recovery phase. The study design also included an evaluation of the reversibility or persistence of the biological effects associated with a 12 months exposure, after a 12-month recovery period. The white mineral oils were administered in the diet at levels of 60, 120, 240 or 1200 mg/kg bw/day.
The parameters investigated included body weight, food consumption, clinical observations, serum chemistry, haematology, ophthalmology, urine parameters and organ weights, including mesenteric lymph nodes. Analyses for mineral hydrocarbons were performed on the liver, kidneys, mesenteric lymph nodes and spleen from female animals. Detailed histopathological examination of 48 tissues, including the liver, spleen, mesenteric and mandibular lymph nodes, Peyer’s patches, kidney, bone marrow and male and female reproductive tissues was conducted for all animals in the control group and at the highest dose in the main (2 year) study and at the 12 month sacrifice.
Based on the results of the study the ANS Panel in 2009 concluded that no carcinogenic effect was observed in the study in F344 rats with MVMO and HVMO. Non-neoplastic effects were limited to infiltration of histiocytes in mesenteric lymph nodes and oil deposition in the liver. These effects were considered to be an indication of MVMO and HVMO exposure rather than an adverse effect. There were no adverse effects on survival, body weight, food consumption, clinical signs, clinical chemistry, haematology, and no treatment-related adverse changes were seen at necropsy or by microscopy.
The ANS Panel in 2009 considered the no-observed-adverse-effect level (NOAEL) for the mineral oils used in the above study to be 1200 mg/kg bw/day, the highest dose tested.
In 2009, the ANS Panel also concluded that, based on the available data, there would be no safety concern with respect to genotoxicity for HVMO and MVMO. The Panel currently confirmed this conclusion.
Based on the present dataset the Panel confirmed the above conclusion and established a group ADI of 12 mg/kg bw/day for HVMO (kinematic viscosity ≥11 mm2/s at 100 °C, a carbon number >28 at 5% distillation point and an average molecular weight >500 g/mol) and MVMO (kinematic viscosity between 8.5 - 11 mm2/s at 100 °C).
According to the applicant MVMO and HVMO are to be used in an interchangeable manner and only up to the maximum levels in the food categories as specified in this opinion. Therefore, the estimated exposure to MVMO also includes the potential use of HVMO and can be considered as the total estimated exposure to both classes of white mineral oils. Thus, the present exposure assessment supercedes the assessment of the HVMO performed by the ANS Panel in 2009 (EFSA, 2009).
The Panel considered the dietary exposure to MVMO and/or HVMO from the proposed uses, which ranged on average from 0.9 – 5.2 mg/kg bw/day across all population groups. High intake estimates ranged from 1.6-10.1 mg/kg bw/day across all population groups.
As regards the residue level of polycyclic aromatic hydrocarbons (PAHs) in MVMO, the applicant proposed a maximum limit for benzo[a]pyrene of 50 µg/kg in accordance with the PAH limit set for E905 microcrystalline wax (Commission Regulation (EU) N° 231/2012). The Panel noted that the scientific opinion of the Panel on Contaminants in the Food Chain on polycyclic aromatic hydrocarbons in food (EFSA, 2008) suggested that the concentrations of a range of PAHs of concern rather than a single PAH should be measured.
The Panel noted that exposure to HVMO and/or HVMO at the established ADI of 12 mg/kg bw/day would result in a daily exposure of less than 0.5 ng/kg bw/day of benzo[a]pyrene. Compared to an estimated median dietary exposure to benzo[a]pyrene of 3.9 ng/kg bw/day, which was derived from the Scientific Opinion of the EFSA Panel on Contaminants in the Food Chain (CONTAM) on polycyclic aromatic hydrocarbons (PAHs) in food, the additional exposure to benzo[a]pyrene from the use of HVMO and MVMO as food additives is considered by the Panel to be of no concern.
In conclusion, the Panel established a group ADI of 12 mg/kg bw/day for HVMO (with a kinematic viscosity at 100 oC not less than 11 mm2/s and for MVMO (with a kinematic viscosity at 100 °C between 8.5 and 11 mm2/s). The group ADI has been derived by applying an uncertainty factor of 100 to a NOAEL of 1200 mg/kg bw/day, the highest dose level tested, in a chronic toxicity and carcinogenicity study in F344 rats.
The Panel noted that the conservative estimates indicated that the potential dietary intake of MVMO and/or HVMO from the proposed uses and use levels as food additive in high consumers would reach up to approximately 10.1 mg/kg bw/day for toddlers and thus, the exposure would be below the established group ADI.
The Panel also noted that additional exposure to MVMO and/or HVMO via other sources could represent a major source of exposure. With the data presently available it is difficult to draw conclusions as to the magnitude of exposure and the number of consumers affected by this potential additional exposure.