Approach for safety assessment of glass fibre-sizing agents in glass fibre-reinforced plastics for food contact

Transcription

1 SCIENTIFIC OPINION ADOPTED: 23 June 2015 PUBLISHED: 14 July 2015 doi: /j.efsa Approach for safety assessment of glass fibre-sizing agents in glass fibre-reinforced plastics for food contact EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) Abstract Following a request from the European Commission, EFSA was asked to review Commission proposals for classification of the substances used as sizing agents and provide an opinion on whether or not the proposed classifications could imply an unacceptable risk to human health. Glass fibre-reinforced plastics are composite materials made of a polymer matrix reinforced with glass fibres. The glass fibres therein are coated with a surface treatment ( sizing agent ) to hold individual filaments together and to promote adherence to the polymer matrix. Glass fibre-reinforced plastic is covered by Regulation (EU) No 10/2011, which stipulates that substances used for its manufacture should be listed in the Union List. From January 2016, the Plastics Regulation will also apply to glass fibre-sizing agents, and these substances shall be included in the Union List. On the basis of the low migration from glass fibre-reinforced plastics and the low consumer exposure expected, the CEF Panel does not expect any particular health risks from sizing agents compared with other plastics. For substances classed as coupling agents and for the substances considered polymer production aids, aids to polymerisation or solvents used to make plastics, any use of glass fibre-reinforced plastics does not seem to merit deviation from risk management decisions that were taken earlier. For the reactive polymers used for sizing the glass fibres, two possibilities are presented: evaluation of these polymers by EFSA and then specific authorisation via the Union List or regulation through the starting materials, if already listed, in accordance with the derogation in Article 6(3) of Regulation (EU) No 10/2011. In either case, the data required and the risk assessment process used should be the same or equivalent. The difference will be in the data that are presented to EFSA, and this is a decision in the remit of the Commission. European Food Safety Authority, 2015 Keywords: safety assessment, glass fibre-sizing agents, glass fibre-reinforced plastic, food contact materials Requestor: European Commission Question number: EFSA-Q Correspondence: fip@efsa.europa.eu EFSA Journal 2015;13(7):4168

2 Panel members: Claudia Bolognesi, Laurence Castle, Jean-Pierre Cravedi, Karl-Heinz Engel, Paul Fowler, Roland Franz, Konrad Grob, Rainer Gürtler, Trine Husøy, Wim Mennes, Maria Rosaria Milana, André Penninks, Vittorio Silano, Andrew Smith, Maria de Fátima Tavares Poças, Christina Tlustos, Fidel Toldrá, Detlef Wölfle and Holger Zorn. Acknowledgements: The Panel wishes to thank the members of the Working Group on Food Contact Materials: Claudia Bolognesi, Laurence Castle, Jean-Pierre Cravedi Konrad Grob, Martine Kolf- Clauw, Eugenia Lampi, Maria Rosaria Milana, Maria de Fátima Poças, Kettil Svensson and Detlef Wölfl, for the preparatory work on this scientific output. Suggested citation: EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), Scientific opinion on an approach for safety assessment of glass fibresizing agents in glass fibre-reinforced plastics for food contact. EFSA Journal 2015;13(7):4168, 11 pp. doi: /j.efsa ISSN: European Food Safety Authority, 2015 Reproduction is authorised provided the source is acknowledged. The EFSA Journal is a publication of the European Food Safety Authority, an agency of the European Union. 2 EFSA Journal 2015;13(7):4168

3 Table of contents Abstract Introduction Background and Terms of Reference as provided by the European Commission Interpretation of the Terms of Reference Data and Methodologies Data Methodologies Assessment Introduction General information as provided by the European Commission Evaluation Conclusions... 9 Documentation provided to EFSA References Abbreviations EFSA Journal 2015;13(7):4168

4 1. Introduction 1.1. Background and Terms of Reference as provided by the European Commission Glass fibre-reinforced plastic (GFRP) is a composite material made of a polymer matrix reinforced with glass fibres. The glass fibres therein are coated with a surface treatment ( sizing agent ) to hold individual filaments together and to promote adherence to the polymer matrix. The sizing agents are composed of: 1) coupling agents (binding glass fibres to organic resins) 2) film formers (binding glass filaments together and protecting them against abrasion), and 3) aids to polymerisation. Article 3(1) of Regulation (EC) No 1935/ applicable to all food contact materials rules that: Materials and articles, including active and intelligent materials and articles, shall be manufactured in compliance with good manufacturing practice so that, under normal or foreseeable conditions of use, they do not transfer their constituents to food in quantities which could: (a) endanger human health; or (b) bring about an unacceptable change in the composition of the food; or (c) bring about a deterioration in the organoleptic characteristics thereof. Commission Regulation (EU) No 10/ on plastic materials and articles intended to come into contact with foods established that only substances included in the Annex I may be intentionally used in the manufacture of plastics (Article 5) but also allows for derogations from this rule under certain conditions (Article 6). Listing in the Annex requires prior assessment by EFSA. Substances falling under the derogations are however subject to the risk assessment by the manufacturers as established in Article 19 of Regulation (EU) No 10/2011. As of 1 January 2016 Regulation (EU) No 10/2011 applies to additives used in glass fibre sizing 3. As a result substances used in sizing agents need to be integrated in the rules established by Regulation (EU) No 10/2011. This prompted questions in particular on the function and nature of the constituents of film formers, as individual film formers can be classified under different derogations under Article 6 of Regulation (EU) No 10/2011. The Joint Reinforced Plastics Working Group (JRPWG) reviewed the classification of constituents of sizing agents, vis-à-vis the definitions of Article of Regulation (EU) No 10/2011. The analysis from the JRPWG showed that glass fibre sizing agents are complex mixtures of substances with different functions of a varying composition applied at different stages of processing. Moreover the quantities of sizing agent components remaining in the final glass fibre reinforced plastic differ. Thus to avoid insufficient or disproportionate rules on sizing agent, constituents need to be more precisely classified. Analogies between the substances used as sizing agents and substance groups addressed in Regulation (EU) No 10/2011 suggest the following classification to manage the risk (see Table 1). 1 Regulation (EC) No 1935/2004 of the European parliament and of the council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC. OJ L 338, , p Commission Regulation (EU) No 10/2011 of 14 January 2011 on plastic materials and articles intended to come into contact with food. OJ L 12, , p See, in particular, Articles 22(4) and EFSA Journal 2015;13(7):4168

5 Table 1: Proposed classification to Regulation (EU) No 10/2011 Substance group Function Examples Analogy Risk management approach Coupling Agents Create an adhesive force Silanes Similar substances already Article 5, Annex I Union List between the fibres and the listed in Annex I (e.g. FCM polymer matrix, and therefore Nos. 142, 377, 453, 788) have an intended effect in the finished plastic material Film Formers Continuous filament glass fibre processing aids (CFGF) - Tie single glass fibre filaments into strands - Protect strands during handling and storage - Disperse chopped strands into the polymer matrix during compounding - Bind fibres to polymer matrix, material property improvement - Maintain stability of sizing raw material preparations - Allow application of sizing to fibres - Allow mechanical processing of fibres Polyester, polyvinyl acetate, polypropylene, polyurethane, epoxy resins Antifoaming agents, surfactants, ph regulators, process biocides, lubricants, antistatic agents Unreactive polymers (not capable of reacting with the plastic matrix) are functionally similar to polymer production aids (PPA) defined in Article 3(8)) of Regulation (EU) No 10/2011 Reactive polymeric (substances capable of reacting with the plastic matrix) are functionally similar to polymeric starting substances and their monomers and other starting substances. True polymer production aids defined in Article 3(8) (a) Article 6(1) and Article 19 Article 5, Annex 1 Union List or if not already listed, Article 6(3)(d) Article 6(1) and Article 19 Risk assessment EFSA Risk assessment by manufacturer EFSA Risk assessment by manufacturer Aids to polymerisation Article 6(4)(b) and Article 19 Risk assessment by manufacturer Solvents Article 6(2) and Article 19 Risk assessment by manufacturer Similar to polymer Production aids defined in Article 3(8) Article 6(1) and Article 19 Risk assessment by manufacturer (a): See list in Union Guidelines on Regulation (EU) No 10/2011 on plastic materials and articles intended to come into contact with food available at chemicalsafety/foodcontact/docs/ _plastic_guidance_en.pdf (page 12) 5 EFSA Journal 2015;13(7):4168

6 To complement this risk management approach it may be necessary to require an analysis of the final product (glass fibre-reinforced plastics). The purpose of such analysis would be to verify its composition and subsequent potential migration of substances not listed in Annex I of Regulation (EU) No 10/2011 including non-intentionally added substances (NIAS) such as reaction products, oligomers and impurities. In accordance with Article 29(1)(a) of Regulation (EC) No 178/2002 4, the European Commission asks EFSA to give its scientific opinion: on whether the classification of the constituents of sizing agents presented in Table 1 is appropriate given their use and purpose; on whether the application of this classification scheme and the envisaged risk management approach indicated in table 1 is suitable to ensure that the final glass fibre reinforced plastic satisfies the requirements of Article 3(1) of Regulation (EC) No 1935/2004, and on whether any additional or alternative restrictions or specifications would be needed to complement the risk management of these sizing agents if the risk management approach as indicated in table 1 alone is insufficient to address the risk Interpretation of the Terms of Reference The classification of substances used in producing plastic food contact material (FCM), including glass fibre-reinforced plastics (GFRPs), is in the remit of the Commission. The Commission asks the European Food Safety Authority (EFSA) if a given classification of substances used for sizing the glass fibres for GFRPs intended for food contact, in particular the polymers for film formation, could give rise to an unacceptable health risk and if special measures would be needed to avoid this. 2. Data and Methodologies 2.1. Data Data were provided by the JRPWG on the migration potential of substances from GFRP. Several examples were analysed using one or more of the following three approaches: solvent extraction of the treated glass fibre samples before incorporation into a plastic, followed by worst-case (100 % migration assumption) calculations or migration modelling; solvent extraction of the final material or article made of GFRP, screening and targeted chemical analysis of the extracts to identify and quantify the migratable substances, followed by an estimation of migration using migration modelling; migration tests on the final material or article made of GFRP followed by targeted chemical analysis of the food simulants to identify and quantify the migrated substances. At the request of the Working Group on Food Contact Materials (WGFCM), five members representing the JRPWG were invited to present the approach proposed by industry and to answer any WG members questions of clarification. This hearing was held on the afternoon of 19 June 2014, in connection with the 61 st meeting of the WGFCM Methodologies To establish the safety from ingestion of migrating substances, toxicological data indicating the potential hazard and the probable human exposure data need to be combined. More detailed information on the data requirements and the general procedure followed by the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF Panel) to evaluate the safety of substances used in food contact plastics is available in the Scientific Committee on Food (SCF) guidelines (EC, 2001). The methodology used here was based on this process, i.e. characterisation of 4 Regulation (EC) No 178/2002 of the European Parliament and of the Council of 28 January2002 laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety. OJ L 31, , p EFSA Journal 2015;13(7):4168

7 the substance(s) used to size glass fibres along with their impurities and reaction and degradation products, and evaluation of the potential for human exposure to these substances through migration. The background information used here was provided by the Commission and it was supplemented by technical information provided by the JRPWG. The physical, chemical and toxicological nature of the sizing agents provided as typical examples were considered, along with the amounts of these substances and the chemistry involved when they are used to treat the surface of glass fibres. The results provided from the chemical analysis of several samples of treated glass fibres and of final samples of GFRPs were then considered to help the Panel form a view of the residual amounts of the various sizing agents used and their probable migration levels during use of the plastics in food contact. Included in these considerations were any impurities and breakdown or transformation products of the sizing agents that the chemical analysis had detected, identified and measured. Finally, typical conditions of use of GFRPs in contact with foods were considered to allow the extent of potential consumer exposure to these migration substances to be assessed. From these considerations of the nature of the substances involved, along with possible migration and exposure levels, the Panel formulated an opinion on the proposals made by the Commission and came to conclusions that address the terms of reference. 3. Assessment 3.1. Introduction EFSA was asked by the European Commission to review the classification of the substances used for sizing glass fibres used in GFRPs intended for food contact and provide an opinion on whether or not the proposed classifications, particularly of the polymers used for film formation, could imply an unacceptable risk to human health. The request has been registered in the EFSA s register of questions under the number EFSA-Q General information as provided by the European Commission Commission Regulation (EU) No 10/2011 on plastic materials and articles intended to come into contact with food establishes a Union List of authorised substances that can be used in the manufacture of plastic food contact materials. Prior to its authorisation, a substance should be assessed by EFSA. Regulation (EU) No 10/2011 clarifies that GFRP is covered by the scope of that Regulation and that substances used for its manufacture should be listed in the Union List. Glass fibres that are incorporated into plastics have to be coated with a sizing agent to increase the adhesion between the plastic matrix and the glass fibre. Other technical functions are provided too. A transitional period is foreseen in Article 23 of Regulation (EC) No 10/2011 until the end of December From January 2016, the Plastics Regulation will apply also to glass fibre-sizing agents, and these substances shall be included in the Union List. Glass fibre sizing is an organic surface treatment applied to glass fibre and mainly includes the use of coupling agents, film formers and processing aids. The purposes of sizing are to allow processing of the fibres, to hold the individual filaments together and to promote adherence of the glass fibres to the polymer matrix. The coupling agents are chemical substances or mixtures that have the ability to bind inorganic materials such as glass fibres to organic resins. The film formers are chemical substances or mixtures that have the ability to bind the glass filaments together and to protect the filament bundles against abrasion during handling, processing and storage. They also usually enhance the bonding properties between fibres and polymer matrices. Processing aids are used in the sizing process and in the processing of glass fibres. During a meeting convened by Directorate General for Health and Consumer Affairs (DG SANCO) in April 2010 with technical experts from Member States, industry and EFSA, possible approaches were discussed. The compliance work for the film-forming polymers could be obtained through either (i) authorisation of the final film or coating on the glass fibre as polymeric additives or (ii) authorisation of the substances used to make these polymers. Industry agreed to perform a study in support of the second option. The study was performed on behalf of a joint industry group of the reinforced plastics production chain, the JRPWG. 7 EFSA Journal 2015;13(7):4168

8 According to the suggested approach (Table 1), the coupling agents, usually silanes, would need to undergo authorisation and would be listed as additives used in glass fibre sizing. For continuous filament glass fibre processing aids and for those film formers that are used as polymer production aids, aids to polymerisation or solvents (Table 1), the substances would not need to be evaluated by EFSA or need specific authorisation and listing by the Regulation, but would require risk assessment by the manufacturer, as is currently the case for substances of these three classes used to make plastics intended for food contact. For the film formers that could be considered to have the function of a polymeric additive, derogations in Article 6(3) in Regulation (EU) No 10/2011 would be applied, enabling their specific regulation through the starting substances Evaluation The Panel emphasises the need to identify all migrating species related to the use of the substance under consideration, including the substance itself, along with any impurities, reaction and breakdown products that may arise from the intended use, and then evaluate toxicological data based on a tiered approach linked to the level of migration and consumer exposure to allow a risk assessment to be performed. Regarding the industry documents describing the analytical methods used and the laboratory test reports, several examples are presented describing screening and targeted analysis of extracts of (i) the treated glass fibre samples before incorporation into a plastic, (ii) the final material or article made of treated GFRP or (iii) migration simulants after contact with such finished materials and articles. These tests follow many of the procedures and principles outlined in the current EFSA Guidance document on the submission of a dossier on a substance to be used in Food Contact Materials for evaluation by EFSA (EFSA, 2008). The tests are comprehensive in their analytical coverage, not only including the substances used but also testing for other migratables such as impurities, reaction products and breakdown products. Therefore, for example, solvent extraction was used to determine the residual content of various sizing agents used to make the GFRP and then conservative migration modelling was used to estimate the migration levels that such a residual content might give rise to under foreseeable conditions of use in contact with foods. As an example, for a GFRP of 2 mm thickness, the calculated maximum migration was estimated to range from 0.08 to 1.9 µg/kg food (the range depending on the assumptions made) for a sizing agent of a molecular weight of 150 daltons and a residual content of 1.5 mg/kg in the GFRP, and was higher at 0.3 to 8 µg/kg food for a sizing agent of higher molecular weight present in the GFRP at a higher residual content of 15 mg/kg. Similar extraction tests and migration calculations and/or migration tests were performed for several other samples of GFRP made using other sizing agents and the findings were similar. Worst-case migration levels of the chemicals monitored including the sizing chemicals themselves, as well as impurities, etc. were generally well under 50 µg/kg, which would require only a reduced toxicological data set according to FCM guidance (EFSA, 2008) for the intended conditions of use in food contact. The Panel noted that these considerations are based on the information available for only some substances considered as representative and used as examples. Considering the results of these tests of representative samples and also considering the typical applications of the use of GFRP, the potential for consumer exposure to migrating substances originating from the sizing agents is expected to be rather low. The substances are used in small amounts to treat the surfaces of glass fibres that are then embedded into the final reinforced plastic. These plastics are then used in typically repeated-use applications with a long service life and the ratio of the surface area of contact to the mass of food in contact is also generally low. Thus, migration and consumer exposure will generally be low. The Panel takes note of the information provided by the Commission, which states that, to complement this risk management approach, it may be necessary to require an analysis of the final product (Glass fibre-reinforced plastics). The purpose of such analysis would be to verify its composition and subsequent potential migration of substances not listed in Annex I of Regulation (EU) No 10/2011, including NIASs such as reaction products, oligomers and impurities. The Panel agrees that assessing the safety is likely to require that relevant samples of treated glass fibres and finished plastic materials and articles are prepared such that the potential migratables can be identified, 8 EFSA Journal 2015;13(7):4168

9 quantified and assessed. The assessment of the substances used in the glass fibre-sizing process should follow EFSA guidelines (EFSA, 2008). In consideration of this, the current EFSA guidelines deal with food contact applications in their entirety, but they do have a particular emphasis on plastics used for retail food packaging. This being so, it is likely that specific considerations or adaptations may be needed for some of the unique manufacturing processes and the food contact applications of GFRPs. This could include the possible formation of migratable reaction products when the sizing agents are present during in situ free radical polymerisation of unsaturated resins to make some thermoset GFRPs. Other considerations should include the effect, if any, of repeated use and possible ageing of materials and articles that could have a long service life; the effect of cleaning with potentially corrosive chemical cleaning agents; renovation or repair of large fixed GFRP vessels; atypical surface area (food mass ratios); and the proper validation of any mathematical migration models that could be used. Considering the proposals in Table 1, polymer production aids, aids to polymerisation and solvents used to make plastics are already self-evaluated by the manufacturer in accordance with risk management decisions made. Article 3 of the Framework Regulation states that exposure to substances from FCMs should not pose a risk to human health. Practically, this means that someone in the manufacturing chain has to demonstrate safety in accordance with internationally recognised scientific principles on risk assessment (Article 19 of the Regulation). As these principles are specified by EFSA guidelines for the risk assessment of substances used to make plastics intended for food contact (EFSA, 2008), these same data are required for safety assessment, independent of whether the glass fibre sizing is specifically regulated through the substances used or the resulting polymers. The difference is in the procedure. In the case of regulation through the substances used, it is likely that most of these substances are already in the list of authorised substances; thus, industry is not compelled to petition for the application but should assess the oligomers, reaction products and impurities, etc., in their in-house documentation. Regulation via the Union List, on the other hand, presupposes petitioning comprising all substances potentially migrating into food. When specifically regulated through the polymers, EFSA evaluates the safety of all substances that migrate, whereas, when regulated through the starting materials, enforcement authorities are required to check the supporting documentation for compliance. 4. Conclusions On the basis of the low migration of sizing agents from GFRPs shown by the JRPWG (for some examples that JRPWG selected as representative) and the low expected consumer exposure, the CEF Panel does not anticipate any particular health risks from sizing agents used to make GFRPs compared with other plastics. For the coupling agents and for the substances considered to be polymer production aids, aids to polymerisation or solvents used to make plastics, use in GFRPs does not seem to merit deviation from risk management decisions that were taken earlier. For the reactive polymers used for sizing the glass fibres, two possibilities are presented. If the starting substances used to make the reactive polymer have already been evaluated and are listed in the Commission positive list, regulation through the starting materials in accordance to the derogation in Article 6(3) of Regulation (EU) No 10/2011 is proposed. If the starting substances are not listed, then evaluation of these polymers by EFSA and then specific authorisation of the reactive polymers via the Union List is proposed. The data required and the risk assessment process used to support the safety stated in the Declaration of Compliance of the final material or article should be the same or equivalent, whether the polymeric material is directly regulated through the polymer or indirectly regulated via the starting substances. The difference will be in the data that are presented to EFSA, and this is a decision in the remit of the Commission. 9 EFSA Journal 2015;13(7):4168

10 Documentation provided to EFSA 1. Glass fibre sizing agents in GFRP. October Submitted by the European Commission. References EC (European Commission), Guidelines of the Scientific Committee on Food for the presentation of an application for safety assessment of a substance to be used in food contact materials prior its authorisation. Available online: EFSA (European Food Safety Authority), Guidance document on the submission of a dossier on a substance to be used in Food Contact Materials for evaluation by EFSA by the Panel on additives, flavourings, processing aids and materials in contact with food (AFC). The EFSA Journal 2008, 21r, EFSA Journal 2015;13(7):4168

11 Abbreviations EU European Union CEF EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids JRPWG Joint Reinforced Plastics Working Group FCM food contact material NIAS non-intentionally added substances EC European Commission GFRP glass fibre-reinforced plastic WGFCM Working Group on Food Contact Materials SCF Scientific Committee on Food DG SANCO Directorate General for Health and Consumer Affairs 11 EFSA Journal 2015;13(7):4168