Globally relevant content Dr. Monika Tönnießen June 2016 Mineral Oil Components in Food Packaging Adhesives
02/11 Mineral Oil Components in Food Packaging Adhesives What is mineral oil? The term mineral oil is not well-defined. There are different understandings what mineral oil means. The European Food Safety Authority (EFSA) defines mineral oil as follows: Mineral oil hydrocarbons () 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. Thus, mineral oil is not a well-defined single chemical substance, but rather a complex mixture of thousands of different substances. Mineral oil hydrocarbons are divided into two kinds of fractions: the mineral oil saturated hydrocarbons (MOSH) and the mineral oil aromatic hydrocarbons (MOAH). Figure 1 Fractions of Mineral Oil Source: EFSA Scientific Opinion on Mineral Oil Hydrocarbons in Food, 2012 MOSH Mineral oil saturated hydrocarbons MOAH Mineral oil aromatic hydrocarbons
03/11 Mineral Oil Components in Food Packaging Adhesives Contamination of food by mineral oil Since 1989 analytical investigations from the Official Food Control Authority of the Canton of Zurich have shown the presence of mineral oil contamination in foodstuff. Since 2010, the topic mineral oil attracted the attention of both politics and media. Several investigations demonstrated that there are different possible sources for the presence of in food: food processing aids (machine oils, de-dusting agents) as well as food contact materials (inks, recycled board, adhesives), food additives and environmental contaminants such as not fully burned fuel oil in the atmosphere. Since 1991, it is well-known that food ingredients transported in jute bags show a high contamination of mineral oil due to the treatment of jute fibers with 5 % to 7 % high boiling mineral oil. According to scientific studies commissioned by the BMELV (Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz, Federal Ministry of Food and Agriculture) and carried out during more than two years (2010 to 2012), recycled cardboard is the main source of mineral oil contamination in foodstuff. The reason for this contamination is the mineral oil content in printing ink used for newspapers.
04/11 Mineral Oil Components in Food Packaging Adhesives Transfer of mineral oil into food The transfer of mineral oil into food follows different mechanisms depending on the kind of foodstuff, either by direct migration or via the gas phase by evaporation and recondensation. The latter transfer is the main contamination mechanism in dry food. Due to this transfer route not only the primary packaging material should be considered in a risk analysis but also a contamination from the secondary packaging (transport packaging). Figure 2 shows the transfer of mineral oil compounds in seven steps from the outer packaging through the inner packaging into the foodstuff. It is easy to understand that only those substances are relevant for the transfer via the gas phase which are relatively volatile, i.e. substances with a C-number up to C24. For the transfer via migration, i.e. applications with wetting contact, also non-volatile substances up to C35 have to be taken into consideration. Figure 2 Transfer of Mineral Oil compounds Evaporation Evaporation Migration Migration and Distribution Migration Condensation and Adsorption Evaporation Cardboard Air Inner bag Schematic illustration of successive processes in transfer of Mineral Oil compounds Migration of mineral oil within the outer packaging (cardboard) Evaporation on the surface of the cardboard Condensation on the surface of the inner packaging and adsorption on the bag Migration of mineral oil within the inner bag Evaporation on the surface of the inner bag Condensation on the foodstuff (cornflakes) and adsorption Migration and distribution of mineral oil within the foodstuff Evaporation Condensation and Adsorption Cornflakes
05/11 Mineral Oil Components in Food Packaging Adhesives Legal situation Apart from the four mineral oil compounds listed and restricted in the Union list of the European Plastics egulation, currently no specific legislation and no legal activity exists in the European Union, which defines or aims at defining limits of mineral oil compounds in food. In 2012, the German Bf (Bundesinstitut für isikobewertung, Federal Institute for isk Assessment) recommended that the transfer of MOAH into food should not be detectable. Since 2011, the German ministry BMELV has been working on a regulation which restricts the transfer of into foodstuff. Three drafts have already been discussed with the relevant parts of the industry. The latest version dates from July 2014. The so-called mineral oil regulation will be the 22nd Amendment of the German Consumer Goods Ordinance and is supposed to regulate the transfer of mineral oil from recycled paper. This regulation will contain restrictions that provide for the maximum amounts of MOSH and MOAH in recycled paper and board for food packaging. In case these values are exceeded in the packaging, the draft still allows the use in food contact application if a particular MOSH and MOAH limit in the foodstuff is not exceeded, e.g. by implementing a sufficient functional barrier. All food contact materials - also food packaging - must comply with both the rules of Article 3 of the Framework egulation (EC) No 1935/2004 and the egulation (EC) No 2023/2006 on good manufacturing practice (GMP egulation). The Framework egulation requires that materials and articles coming into contact with food shall be manufactured in compliance with good manufacturing practice in such a way that they do not endanger human health. Even in the absence of a specific regulation for, there is a not ignorable legal demand for food safety and consumer protection. Mineral oil is not an important topic in US. Mineral oil is listed as an indirect food additive in a number of FDA 21 CF sections, such as 175.105 for adhesives and 176.170 for components of paper and paper board. Nevertheless, it should always be considered that the adhesives regulation requires a functional barrier or the use of a quantity of adhesive which allows food contact only in trace amounts at seams, and the paper and paperboard regulations require extraction tests under the intended conditions of use, all of which is the responsibility of the manufacturer of the final food contact article. The Chinese standards currently name two kinds of mineral oils: GB 7189-2010 lists a food grade paraffin wax and GB 4853-2008 a food grade white oil. The Chinese authority has sent out an invitation in May 2016 to discuss the mineral oil topic putting the main focus on MOAH as the mineral oil fractions with the highest risk to human health. Part of the discussions is the option to implement a possible restriction into GB 9685 for MOAH.
06/11 Mineral Oil Components in Food Packaging Adhesives What is the impact on human health? The possible impact of the mineral oil hydrocarbons in human health varies widely due to the very different structure of the single compounds. As the chemical composition of the mineral oil hydrocarbons is mostly unknown, and due to the lack of reference standards for exposure, it is nearly impossible to carry out a proper toxicological risk assessment. Due to the aromatic content of the MOAH fraction the presence of carcinogenic and mutagenic substances cannot be excluded. Like the well-investigated PAHs (polycyclic aromatic hydrocarbons) such aromatic compounds may interact with the DNA, i.e. the genetic material of human cells and can consequentially cause cancer. Therefore, these mineral oil components may represent a severe health risk. Animal studies show that MOSH can accumulate in various tissues, mainly in liver and lymph nodes and may be involved in the formation of granulomas. Overall, the relevance of MOSH for human health is still not fully clarified. In addition to these mineral oil fractions with toxicological concern there are also mineral oil compounds which the EFSA has evaluated as fit for food contact. The Plastics egulation lists four different mineral oil compounds suitable for food contact, two paraffinic waxes (FCM 93, 94), paraffinic white mineral oil (FCM 95) and hydrogenated petroleum hydrocarbon resins (FCM 97). Most of these substance groups are named in the European Union list without specific restrictions. One mineral oil compound, a microcrystalline wax, is even approved as a food additive under the E number 905 in the EU.
07/11 Mineral Oil Components in Food Packaging Adhesives How can MOSH / MOAH be detected? Due to the complexity of the mineral oil hydrocarbons the chromatograms of the MOSH and MOAH fraction do not consist of only a few peaks but mostly show humps of peaks in which only a limited number of single substances can be identified unequivocally. The majority of detected substances remains unknown. To date, there is no standardized analytical method available for MOSH / MOAH determination. The most common test method is the procedure developed by Koni Grob in 1997, which is also recommended by the German Bf. In this so-called manual method extracted test samples are pre-separated by a conventional liquid chromatography column (LC) and afterwards analyzed via gas chromatography with flame ionization detection (GC-FID). Another method is the coupled HPLC-GC-FID also described by K. Grob, in which a pre-separation is carried out by high performance liquid chromatography (HPLC) coupled to GC with FID. This method has a higher sensitivity and can be automated, but the required analytical equipment is available only in a few laboratories. Using both methods, GC it is able to determine the sum of the MOSH and MOAH fractions but only few single substances can be identified. In case polyolefins are present in the sample a separation of polyolefin oligomeric saturated hydrocarbons (POSH) from MOSH is impossible. It is well-known that some substances migrating from hotmelt adhesives can be mistaken as migrating from recycled paper and cardboard. In 2012, EFSA recommended to improve the analytical methods, especially to separate MOAH and also MOSH into different structural subclasses. The importance of this recommendation cannot be underestimated, as the most frequently applied flame ionization detection is not capable of differentiating between the MOSH and MOAH species, or even between MOSH and MOAH at all. Manual method for MOSH / MOAH analytic
08/11 Mineral Oil Components in Food Packaging Adhesives Which food packaging adhesives may contain mineral oil compounds? Food packages consist of various packaging materials containing also adhesives of very different technologies. Depending on their chemistry, adhesives for food packaging may contain mineral oil compounds. Due to the low amount compared to other packaging materials, adhesives are not the main source of mineral oil compounds present in a packaging. The following types of adhesives may contain mineral oil compounds: Water-based adhesives Possible mineral oil compounds in water-based adhesives usually occur from the presence of mineral oil-based defoamers which represent an amount of below 0.5 % of the adhesive formulation. Hotmelt adhesives Hotmelt adhesives may contain a certain amount of mineral oil compounds due to the use of hydrocarbon resins and waxes in the formulations. Figure 3 shows the different technologies of food packaging adhesives, their possible content of mineral oil compounds and their typical applications. It also shows a Henkel solution to minimize the risk of possible mineral oil contamination by choosing the right raw materials for food packaging adhesives. Pressure sensitive adhesives (PSA) Pressure sensitive adhesives composed of water-based formulations may contain a small amount of mineral oil defoamer. PSA products based on hotmelt formulations may contain a relatively high amount of mineral oil, waxes and hydrocarbons. Very often, hotmelt pressure sensitive adhesives are not used in direct contact with the foodstuff but behind a sufficient functional barrier, which helps to prevent the migration of compounds into the food. Figure 3 Overview of mineral oil in different types of packaging adhesives Packaging adhesives Water-based adhesives Hotmelt adhesives Pressure sensitive adhesives (PSA) Polyurethane adhesives Water-based PSA Hotmelt PSA Constituent of the formulation Defoamer based on (< 0.5 %) Waxes hydrocarbon resins Defoamer based on (< 0.5 %) Oils (10 30 %) Waxes hydrocarbon resins No Typical application Labeling packaging construction Cardboard closing Coldseals self-adhesive labels Labeling tapes Lamination isk minimization by raw material exchange Use of mineral oil defoamer based on FCM 95 or mineral oil free defoamer Use of mineral oil components based on FCM 93, 94, 97 Use of mineral oil defoamer based on FCM 95 or mineral oil free defoamer Use of mineral oil components based on FCM 93, 94, 95, 97 or recommendation of a barrier No risk
09/11 Mineral Oil Components in Food Packaging Adhesives Options to reduce the mineral oil contamination of foodstuff Several options have been discussed to reduce the mineral oil transfer into foodstuff: using only cardboard made of fresh fiber, specific selection of waste paper for the recycling process, barrier solutions. At the moment, the only efficient solution is the implementation of a sufficient functional barrier. Different technologies are used for the barriers: Implementation of an inner bag with barrier properties Different plastic materials with barrier layers (e.g. polyester, ethylene vinyl alcohol, polyamide) are used to reduce the transfer of mineral oil into food. Nanolayers based on AI or SiOx represent efficient functional barriers. This technology is the so-called bag in box solution. Coating on cardboard Different substances (e.g. crosslinked polyvinyl alcohol, polyester) are coated on the inner surface of the cardboard by extrusion or by printing. This technology is the so-called barrier on box solution. Adding an absorbent to the cardboard There is the possibility to add activated carbon as an absorbent to the cardboard, for the mineral oil compounds to transfer into these particles. A functional barrier has the effect to delay the transfer of particles into the foodstuff. This delay time is the so-called lag time of the barrier. It is well-known that paper and cardboard are no sufficient barriers to prevent migration of mineral oil compounds. Polyethylene has a lag time of only a few minutes, whereas PET has a lag time of more than one year. The choice of the barrier layer always requires to consider the shelf life of the foodstuff. The lag time should be larger than the shelf life to avoid any contamination. The table below (Fig 4) shows a non-exhaustive list of different functional barriers reducing the transfer of substances below a level of 10 ppb. Figure 4 Examples of functional barriers reducing the transfer of substances Film structure Base polymer Barrier material 36µm O-PET corona treated PET PET 12µm PET metallized PET Metallization 12µm PET / SiOx PET SiOx 6µm aluminium 1) Aluminium 6µm aluminium 1) / PE PE Aluminium 1) Note: only if there are no pinholes or other damages present
10/10 Mineral Oil Components in Food Packaging Adhesives Key take aways Mineral oil is a complex mixture of thousands of different substances with completely different toxicological profiles. There are two fractions, the mineral oil saturated hydrocarbons (MOSH) and the mineral oil aromatic hydrocarbons (MOAH). The transfer of mineral oil into food occurs either by direct migration or via the gas phase by evaporation and recondensation. Packaging adhesives may contain different mineral oil compounds. In some cases a sufficient functional barrier is needed to reduce the transfer of mineral oil into the food. Henkel offers adhesive solutions without petroleum-based mineral oil. Literature and useful links EFSA website http://www.efsa.europa.eu/en/topics/topic/mineraloilhydrocarbons Scientific Opinion on Mineral Oil Hydrocarbons in Food http://www.efsa.europa.eu/de/efsajournal/pub/2704 Abschlussbericht Altpapier-Projekt BMELV: http://www.bfr.bund.de/cm/343/ergebnisse-aus-dem-entscheidungshilfeprojekt-altpapier-des-bmelv.pdf Stellungnahme des Bf zu Übergängen von Mineralöl aus Verpackungsmaterialien aus Lebensmitteln: http://www.bfr.bund.de/cm/343/uebergaenge_von_mineraloel_aus_verpackungsmaterialien_auf_lebensmittel.pdf Bf opinion on the migration of mineral oil from packaging materials to foodstuffs: http://www.bfr.bund.de/cm/349/migration_of_mineral_oil_from_packaging_materials_to_foodstuffs.pdf Analytical methods: Ch. Droz and K. Grob, Determinantion of food contamination by mineral oil material from printed cardboard using on-line coupled LC-GC-FID, Z. Lebensm. Unters. Forsch. 205 (1997) 239-241 K. Grob and M. Biedermann, On-line coupled high performance liquid chromatograpihy gas chromatography for the analysis of contamination by mineral oil, part 1: method of analysis, J. Chromatogr A. 1255: 56-75 (2012)
11/11 Mineral Oil Components in Food Packaging Adhesives Meet your experts Dr. Monika Tönnießen is a chemist by profession and works in the Product Safety Department of the Henkel Adhesive Technologies division. Since 2006 she deals with customer inquiries and is an expert on all food contact related questions. She is member of the paper & packaging group of the European Adhesive Association FEICA. Further information Visit the Food Safe Packaging Premium Area offering webinars, white papers, FAQs, videos and more: Contact us! Many options available. www.henkel-premium-area.com Webinars Our webinars allow you to directly communicate with our Henkel food safety experts. Check our website for the dates of upcoming webinars. Mineral Oil Components in Food Packaging Adhesives Essentials you need to consider Henkel AG & Co. KGaA 40191 Düsseldorf, Germany www.henkel.com/foodsafety The information provided herein, especially recommendations for the usage and the application of our products, is based upon our knowledge and experience. Due to different materials used as well as to varying working conditions beyond our control we strictly recommend to carry out intensive trials to test the suitability of our products with regard to the required processes and applications. We do not accept any liability with regard to the above information or with regard to any verbal recommendation, except for cases where we are liable of gross negligence or false intention. The information is protected by copyright. In particular, any reproductions, adaptations, translations, storage and processing in other media, including storage or processing by electronic means, enjoy copyright protection. Any exploitation in whole or in part thereof shall require the prior written consent of Henkel AG & Co. KGaA. Except as otherwise noted, all marks used in this document are trademarks and/or registered trademarks of Henkel and/or its affiliates in the US, Germany, and elsewhere. Henkel AG & Co. KGaA, 11/2016