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Session on Non-Intentionally Added Substances (NIAS) @ Eurotox 2014

Eurotox 2014
Edinburgh, Scotland, United Kingdom
10/09/2014

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PROGRAMME

Session on ‘Non-Intentionally Added Substances (NIAS) in food contact materials and food: how much do we need to know about the unknown?’

The programme of the session is available here (latest version: 11 August 2014). It was supported by ILSI Europe Packaging Materials Task Force.

BACKGROUND AND OBJECTIVES

The European Framework regulation on food contact materials requires that the transfer of constituents into food should not endanger human health, which is to be demonstrated through a safety assessment according to internationally recognised principles. The risk assessment should cover the regulated substances intentionally used in the manufacturing of food contact materials as well as non-intentionally added substances (NIAS) such as impurities, breakdown products, oligomers and contaminants. Theoretically, it is logical to assess the risk of all substances released from food contact materials into the food we consume. Practical limitations to this are analytical capabilities to identify non-intentionally-added substances (NIAS), the large number of substances, availability of standard materials, and ethical and monetary constraints to animal testing. At the same time, natural food also contains thousands of unknown substances, but is regarded as safe due to its history of safe use. Similarly, during the last decades, safety assessments of food contact materials by manufacturers focussed on new raw materials. This session presented recent examples of NIAS and their toxicological assessment as well as new approaches for prioritisation of NIAS analytics and risk assessment. The summary discussion addressed different aspects and views about the way forward in the safety assessment of NIAS.

ABSTRACTS/PRESENTATIONS

Non-intentionally added substances in food contact materials: EU regulatory requirements and safety assessment (presentation not available)
Dr Hans Ketelslegers (ExxonMobil, BE)

Food contact materials (FCM) may contain substances which have not been added intentionally during the production process. These so called non-intentionally added substances (NIAS) can be impurities, but also include decomposition products of materials that are intentionally added for a specific purpose (e.g. anti-oxidant) or reaction products (e.g. oligomers in polymers). NIAS have been recently defined in (inter-)national regulations, which further emphasises the need for their safety assessment. As a consequence of the regulations and driven by sound product stewardship principles, a number of industry efforts are currently ongoing to address robust and efficient analytical and safety assessment of NIAS, such as the ILSI Europe NIAS and TTC working groups and the Plastics Europe Oligomers program. In this presentation, an introduction to NIAS and an overview of the various regulations dealing with NIAS will be provided. In addition, a high level overview of some of the industry efforts will be presented, and an example will be given of an approach for a safety screen for poly-olefins used in FCM.

Assessing safety of non-intentionally added substances in polymers used for food contact applications
Dr Heli Miriam Hollnagel (Dow Europe, CH)

The manufacture of polymers requires not only monomers as raw materials, but also other substances such as catalysts, processing aids, solvents, stabilisers, lubricants for machinery and additives such as anti-oxidants or colorants. The resulting polymers are used to either form food contact articles such as a cups or packaging films, or functional polymers for use in adhesives or coatings. Given the complex nature of the polymers, different EU or national legislations mandate various forms of notification depending on the type of raw materials and decomposition products. Additionally, post-manufacture, polymers may undergo further processing and modifications, which are no longer under the control of the polymer manufacturer. Hence, it is important for manufacturers and the supply chain to conduct safety assessments for intentionally and non-intentionally added substances (NIAS). Addressing the safety of intentionally added substances is relatively straightforward as standard materials, analytical methods, purity information and toxicological data are typically available and accessible. However, when a multitude of unknown chromatogram peaks arise at trace levels corresponding to NIAS, it is a considerable challenge to address their safety due to paucity in the methods for identification, quantification and data for safety assessment. A caveat to this observation is that similar chromatograms are observed in many natural and man-made materials used in food contact for decades or longer when analysed using modern analytical tools. Based on examples, this talk will provide an overview of the approaches and limitations in the assessment of NIAS in polymers used in food contact applications.

Dr Hollnagel’s presentation is available upon request on HMHollnagel@dow.com.

Assessment of non-intentionally added substances from food contact materials in food: Which way to go?
Dr Beat Brüschweiler (Federal Food Safety and Veterinary Office, CH)

Starting substances for the production of food contact materials (FCM) have to be toxicologically evaluated according to the EFSA note for guidance for FCM depending on their migration level into food. This toxicological evaluation does not necessarily cover non-intentionally added substances (NIAS) such as reaction products, oligomers and impurities which may have chemical properties different from the starting substances. At present, a harmonised and officially approved procedure does not exist how to assess the health risks of NIAS. Differentiation has to be made between identifiable and non-identifiable NIAS. For the former group and in situations where no or insufficient toxicity data are available, the threshold of toxicological concern (TTC) approach is a very useful tool to determine the levels of concern. Additional in silico hazard profiling (e.g. prediction of metabolites, oral bioavailability, specific protein binding, accumulation potential, structural alert for reproductive and developmental toxicity etc.) is recommended to identify the most critical targets, processes and pathways. For the non-identifiable NIAS, in vitro bioassays should be performed to test the FCM migrates/extracts for endpoints of concern at low exposure levels, particularly for genotoxic and endocrine activity. High sensitivity of the selected genotoxicity tests is required to cover the very low TTC level for substances with structural alerts for genotoxicity. In vitro bioassays in combination with analytical chemistry could direct the way to identify the most active substances in mixtures and to assess them in more detail.

To download Dr Brüschweiler’s presentation, please click here.

Non-intentionally added substances: Approaches for prioritisation
Dr Geert Houben (TNO, NL)

Non-intentionally added substances (NIAS) in food packaging materials might migrate to food. To assess the safety of NIAS, three different types of NIAS can be distinguished: predictable NIAS, identified, unpredictable NIAS and unidentifiable, unpredictable NIAS. In case the identity of the NIAS is known, conventional safety assessment approaches can be applied, including read across or the TTC concept. But how to deal with the safety assessment of unidentifiable, unpredictable NIAS?For this category of NIAS the risk assessment approach for unknowns as published by Rennen et al. 2011 and Koster et al. 2013 could be applied. This approach is exposure-based after exclusion of the presence of specific groups of compounds following the Kroes et al. TTC decision tree (2004) and modifications proposed by Munro et al. (2008). An exposure-threshold of 90 µg/day (Cramer class III threshold) can be applied for the safety assessment of the NIAS concerned if it can be demonstrated that the unidentified NIAS is not genotoxic, not an organophosphate/carbamate and does not belong to substances which are excluded from the TTC. This can be determined by a step-wise approach covering general analytical screening (forest of peaks design), conversion of the peaks to an estimated intake, targeted analysis and exclusion of genotoxicity by a bioassay. Only for NIAS above the exposure threshold or NIAS excluded from the approach further steps may be needed for safety assessment.

To download Dr Houben’s presentation, please click here.

CONTACT

For more information on this workshop, please contact Mr Jeroen Schuermans, Scientific Project Manager at jschuermans@ilsieurope.be.

MORE INFORMATION

Visit the Eurotox 2014 website.