Risk Assessment of NIAS in Food Contact Adhesives

Transcription

1 Dr. Monika Tönnießen and Dr. Matthias Frischmann September 2017 Risk Assessment of IAS in Food ontact Adhesives Globally relevant content

2 2/8 Risk Assessment of IAS in Food ontact Adhesives What are IAS? IAS is the abbreviation for non-intentionally added substances. This term was first mentioned in the Plastics Regulation, Regulation (EU) o 10/2011. In recitel 18 and 20 of this regulation IAS are defined as impurities, reaction products and degradation products. The General Guidance on Regulation (EU) o 10/2011 distinguishes four different types of IAS: impurities, by-products, decomposition products and reaction products. There is no food contact material without IAS. All ingredients of a food contact material might be transferred into foodstuffs, which includes the IAS with a low molecular weight below 1000 Da. G/MS screening of a migration solution can help to detect migrated IAS, though it is quite difficult to identify and quantify these substances. Therefore, sharing and exchanging information in the supply chain is a key factor to assess IAS.

3 3/8 Risk Assessment of IAS in Food ontact Adhesives IAS Along the Value hain At each stage of the value chain IAS might be introduced into a food contact material. A strong communication in this chain is essential to identify these substances and to be able to carry out a proper risk assessment. Examples for possible IAS in different types of adhesives are: // By-products as IAS Polyurethane adhesives are often polyester-based. The polyesters are formed by the reaction of diols with diacids. During the production not only polymeric esters are formed but also cyclic esters as unintended by-products. These small molecules easily migrate and have to be risk assessed as IAS. Many water-based adhesives contain a polyvinyl acetate dispersion. It is well-known that during the polymerization of polyvinyl acetate the substances formaldehyde, acetaldehyde, methyl acetate and acetic acid are formed. Also these by-products need to be considered as IAS. Polyvinyl alcohol is an often-used raw material in water-based adhesives. This polymer always contains a technically unavoidable amount of methanol, methyl acetate and sodium acetate as IAS. Figure 1 Polymer Intended main reaction By-products as IAS Unintended side reaction Diols Diacids Long chain polyester yclic esters // Decomposition products as IAS All hotmelt adhesives need stabilizers (antioxidants) to protect the polymer against oxidative degradation. Very often phosphites are used as antioxidants. During storage and in case of thermal stress the phosphite stabilizers in the products are oxidized and afterwards hydrolyzed and form decomposition products. TPP (trisnonylphenyl phosphite) is a well-known stabilizer used for PE material. TPP is listed in the Plastics Regulation (FM 69) and evaluated on European level. After its decomposition this antioxidant releases nonylphenol which is considered as hazardous substance with an endocrine effect. Figure 2 Stabilizer Decomposition product as IAS P xidation Hydrolysis H TPP (AS no ) onylphenol (AS no )

4 4/8 Risk Assessment of IAS in Food ontact Adhesives // Impurities as IAS The raw materials used for adhesives might contain impurities: Polyurethane adhesives are often based on aromatic isocyanates such as 4,4 -MDI and 2,4-TDI. Both monomers contain isomers (2,4 -MDI, 2,2 -MDI respectively 2,6-TDI) as technically unavoidable IAS. The polyurethane laminating adhesives are often based on solvents like ethyl acetate. It is well-known by literature that ethyl acetate contains ethanol, acetaldehyde and acetic acid as impurities due to its production process. Hotmelt adhesives are often polyolefin-based products. Flexible food packaging materials might contain PE or PP films. These polymers always contain a certain amount of low molecular weight oligomers, the so-called PSH (polyolefin oligomeric saturated hydrocarbons) which are IAS and need to be considered as migrateable substances. Figure 3 Monomers H 2 4,4 -MDI 2,4-TDI Isomers as IAS H 2 H 2 2,4 -MDI 2,2 -MDI 2,6-TDI // Reaction products as IAS Aromatic isocyanates are hydrolyzed easily during the application and curing process of polyurethane adhesives at the stage of the converter. These substances create primary aromatic amines (PAA) which are hazardous and considered as carcinogenic, e.g. MDI reacts to MDA as IAS. Figure 4 Monomer Reaction product as IAS H 2 H 2 Methylene diphenyl diisocyanate (MDI) Methylene diphenyl diamine (MDA)

5 5/8 Risk Assessment of IAS in Food ontact Adhesives How are IAS Defined in Analytical Assessments? The screening of migration solutions via G/MS (gas chromatography mass spectrometry) is a well-established and commonly accepted way to gain insight to unexpected and non-intentionally added substances. This technique offers characteristic mass spectra based on mass fragmentations, which help to identify those compounds clearly, either via manual interpretation of the fragmentation patterns or via comparison with comprehensive spectral libraries. For example, a wide range of above mentioned cyclic esters as well as stabilizerderived decomposition products can effectively be monitored using G/MS. Some compounds however cannot be analyzed via gas chromatography, as they are not volatile enough, or might decompose in the course of analysis due to thermal impact. In those cases, other analytical techniques should be considered, based on the chemical composition of the food contact material and the knowledge of typically expected IAS to be expected when using this chemistry. For example, primary aromatic amines (PAA) derived from polyurethane-based adhesives are typically not covered by a general G/MS screening and should be assessed by a targeted, specific test method like e.g. HPL-UV (high performance liquid chromatography UV detection) or L/MS (liquid chromatography mass spectrometry). It is self-evident that the wide range of expected and unexpected IAS needs strong communication along the supply chain to allow for an efficient analytical assessment. Figure 5 Monitoring using G/MS Gas chromatograph with attached mass spectrometer (G/MS) Gas chromatogram Extracted mass spectra Injection needle Detector arrier gas Splitter Injection port G column Unknown 1 = Substance A m/z Identification via spectral database and / or manual interpretation Time Unknown 2 = Substance B m/z

6 6/8 Risk Assessment of IAS in Food ontact Adhesives How are IAS Risk Assessed and ommunicated? IAS are not intended to be included into the Union list of the Plastics Regulation. evertheless, some of the above mentioned IAS are listed because their use as monomers or additives for plastic materials is permitted. According to the General Guidance on Regulation (EU) o 10/2011 IAS have to comply with the general safety requirements of article 3 of the Framework Regulation and are subject to risk assessment in line with article 19 of the Plastics Regulation. Article 3 of the Framework Regulation (E) o 1935/2004 requires that materials and articles coming into contact with food shall be manufactured in such a way that they do not transfer substances into foodstuff in an amount which might endanger human health, cause an unacceptable change in the composition of the food or change the organoleptic characteristics of the food. Article 19 of the Plastics Regulation demands to assess unlisted substances, i.e. substances not yet included in the Union list, in accordance with internationally recognized scientific principles on risk assessment. In consequence, this means that for IAS the same rules have to be applied as for IAS (intentionally added substances). Henkel s evaluation of IAS starts with the food contact raw materials. In our food contact raw material questionnaire we ask our suppliers to list all possible impurities of the raw materials, by-products such as oligomers, decomposition products and reaction products. We also require information about the quantity of these substances in order to be able to carry out a risk assessment based on a worst case calculation. We additionally ask our suppliers if they are aware of possible IAS which might have been developed during the processing or application of the raw material under certain conditions or in contact with certain foodstuffs. After collecting all supplier information and identifying IAS by analytical assessments, we are finally able to create detailed food contact statements. These inform our customers about possible IAS in our raw materials, IAS produced on our stage of the supply chain, i.e. during our production, as well as about IAS our customers might create on their stage of the value chain (e.g. the development of PAAs as a result of an incomplete curing process or PAAs released from a fully cured polyurethane adhesive by hydrolytic decomposition under retort conditions). The IAS chapter represents an important part in our food contact statements. It allows our customers to identify unexpected substances that might possibly migrate. Thus, these will not remain unknown substances causing an uncontrollable issue but become known substances which can be risk assessed for the final product. Due to technical and scientific progress as well as changing customer demands in application, the risk assessment of IAS is not a singular event, but requires constant surveillance and revision of associated documentation.

7 7/8 Risk Assessment of IAS in Food ontact Adhesives Key Take Aways IAS are non-intentionally added substances, either impurities, by-products, decomposition products or reaction products. IAS might occur on each stage of the value chain. They have to be identified and quantified by analytical assessment. IAS have to be risk assessed in the same way as intentionally added substances. Either they are evaluated on European level, e.g. they are listed in the Union list of the Plastic Regulation, or they have to be assessed according to the requirements of article 3 of the Framework Regulation applying internationally recognized scientific principles. A strong communication throughout the whole value chain is the key factor to allow each member of the supply chain to identify IAS and to manage their risks. Literature and useful links Framework Regulation (E) o 1935/ Plastics Regulation (EU) o 10/ Union Guidelines on Regulation (EU) o 10/2011 on plastic materials and articles intended to come into contact with food

8 8/8 Risk Assessment of IAS in Food ontact 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 a member of the paper & packaging group of the European Adhesive Association FEIA. Dr. Matthias Frischmann is a food chemist by profession and works in orporate Analytics. He is responsible for the Instrumental Analysis Group and a study director according to GLP and GMP guidelines. Since 2008 he is responsible for migration testing and the evaluation of food contact materials with special focus on adhesives and coatings. Further information Visit the Food Safe Packaging Premium Area offering webinars, white papers, FAQs, videos and more: ontact us! Many options available. Webinars ur webinars allow you to directly communicate with our Henkel food safety experts. heck our website for the dates of upcoming webinars. Henkel AG & o. KGaA Düsseldorf, Germany 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 & o. 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 & o. KGaA, 9/2017