10 Apr 2018

Ensuring the safety of polymers used in food contact materials

Polymers are some of the most versatile materials in existence and are used in all aspects of our daily lives. They have revolutionized the manufacture of items made of plastics which we might use every day and which we assume are extremely safe to use. Food contact materials such as packaging or processing equipment are likely to have plastic (or polymer components. The determination of residual solvents and VOCs in the polymers used in these products is key to mitigating potential contamination risks, health risks and to meet industry regulatory standards which demand that residual solvents should be identified and quantified – sometimes to extremely low levels.

The identification and quantification of non-intentionally added substances (NIAS) has recently become a hot topic. NIAS can include substances present in the polymer formulation such as impurities, contaminants, reaction and polymer degradation products which could pose a potential risk to human health. In order to assess and mitigate these risks, a good understanding of what substances are present is critical. This demands sensitive and robust analytical techniques that can provide reliable data in relatively short time periods to facilitate decision making and the design of comprehensive quantification studies, should the need arise.

The application of the right technology is key to a successful investigative or quantitative study for polymer analysis in general. At Intertek, we utilise thermal desorption gas chromatography time-of flight mass spectrometry (GC/Q-TOF) for residual solvent analysis and when used in conjunction with a Multi-Purpose Sampler (MPS), automation of sample preparation using both static headspace and thermal desorption allows a highly efficient analysis throughput. For a long time we had observed that high resolution accurate mass GC-MS has an important part to play in polymer analysis and, with the rapid evolution of analytical technologies, today's GC/Q-TOF instruments are dependable, robust and allows flexibility in method design and application.  This technology is ideal for screening for NIAS as a preliminary step in assessing food contact materials. The materials (card, plastic or board) are sampled into appropriate amounts and then directly analysed (no solvent extraction). This has the benefit of being quick and relatively low-cost and can help to identify problems early on in the process of NIAS assessment. This data can be useful to build up a picture of substances present in a client's products which can also support batch to batch comparisons during quality control or process control programs. This no-solvent extraction approach also avoids the potential risk of cross-contamination that may originate from the extraction solvents however it must be recognized that this screening experiment does not represent a full NIAS analysis and will not facilitate full NIAS quantification.

Call to Action:
Accurate analysis and measurement is critical to assessing the safety of polymer containing food contact materials with respect to NIAS. Robust measurement can only be achieved through appropriate application of the correct analytical technology and methodology.  Experienced scientists are needed to firstly, develop the methods and secondly, drive insight from the generated data. Are you sure you fully understand the potential NIAS risks associated with your polymer products?

For more information visit our webpage:
Non Intentionally Added Substances (NIAS) and Food Contact Materials