Recycled Plastics and Medical Grade Plastics – Can they go together?

Everybody is talking about sustainability. This mega trend also extends to into the MedTech space. Sustainability is requirement for new products to improve reduce the climate footprint as well as to increase the circularity of the product. But does sustainability and medical grade plastics go together, and if yes how? Let’s explore the question!

Medical Grade Plastics – an offically undefined term

Unfortunately, the term «medical grade plastic» has no official definition. The closest to official definition is the guideline «VDI 2017 medical grade plastic». However, this is a industry initiative and a guideline which is not (yet, hopefully) a Norm. The requirements recommended by the VDI 2017 are in summary:

• Change Management of the material supplier
• Supply Security Measures such as discontinuation periods
• Formulation Consistency
• Regulatory Support
• Biocompatibility

As already mentioned, this is not a binding regulation but a guideline. This means that a plastic grade can be called «medical grade» without it fulfilling all above stated requirements. For the purpose of this article, we will accept the definition according to the VDI 2017 of medical grade plastic.

The requirements in the VDI guideline are designed such that the material supports the fulfillment of the regulatory requirements for medical devices and other MedTech applications. But let’s explore a what the european medical device regulation says about the material used for the manufacture of medical devices.

Regulatory Requirements and Biocompatibility

The MDR requires the manufacturer of a medical device to ensure that said device is safe. Thereby special attention must be paid to biocompatibility. Phthalates, Animal / Human Substances, Nanomaterials, CMR-Substances and Endocrine Disruptors are all explicitly mentioned as substances to be included in the biocompatibility examination. So overall, the MDR does not state much about supply security, formulation consistency or change management. MDR is only concerned with patient safety and achieving it in a risk-based manner. So, with the right biocompatibility test plan, the use of recycled materials may be possible. But let’s define what «recycled material» even is exactly.

Sustainable Materials – A plethera of solutions

There are a variety of sustainable alternatives for virgin plastic. All of them claiming to be THE solution to the world’s problems. Take these claims with a grain of salt, material manufacturers are trying to sell material, that is their business, there is no perfect «one size fits all» solution. The alternatives listed below are the most prevalent sustainable material solutions on the market right now:

• Recycled plastics
• Biobased plastics
• Biodegradable plastics (biobased or not)
• Downgrading virgin plastic (e.g. PP instead of PA)

In this article we will focus on recycling plastics. For more info on other sustainability strategies and alternative material other than recycled materials follow us on Linkedin or contact your Gradical Expert.

Recycled Plastics

The recycled plastics are mainly categorized according to their method of recycling – mechanical or chemical and their origin – post-consumer and post-industrial.

Mechanical recycling is the process were waste plastic is collected, shredded, washed and regranulated. It improves the climate footprint as well as the circularity of the used material and was until recently cheaper than virgin material. The supply of waste plastic is increasing due to increasing plastic recycling streams and plastic use.

Chemical recycling uses heat, solvents and pressure to break the polymer down into either its monomers or reoil (a mixture like crude oil which can be processed in the same way). After that either the monomer or the reoil are processed exactly as petrochemicals would to get virgin plastic. The advantage of chemical recycling are the quality and consistency of the resulting polymer, but it uses, in most cases, even more energy than the production of virgin plastic. So, depending on the energy mix it might not be climate friendly at all. On top of that all that chemical processing comes with a hefty price increase and the production is not scaled as well as the traditional petrochemical industry. Chemical recycling may be the future, but it certainly is a long way till then.

The origin of the recycled plastics is the next important point for categorizing them. Post-industrial recycled plastics are industrial wastes that cannot be used in the production anymore. A good example are sprues from injection molding or non-conforming semi-finished products. These are of high purity and quality as well as traceable to one grade. These wastes are inefficiencies in the production process and companies are trying to eliminate them. Therefore, the availability of such waste is declining, and they might not be a good long term strategy.

Post-consumer waste on the other hand, as we are frequently reminded, is increasing. The availability is increasing, and the processing methods are improving. For example, PET is meanwhile available as food grade post-consumer mechanical recycled material. A thing thought to be impossible in the not so recent past.

As we now have an overview of the recycled plastic landscape, lets investigate each class on its ability to fulfill the requirements of the VDI2017.

Chemically recycled post-consumer plastics

It is entirely possible to get a medical grade plastic according to the VDI2017 with chemical recycling. The drawbacks are its high energy use, and therefore bad carbon footprint (depending on the energy mix), it’s price and availability. Here we have an option that works, however the viability in terms of sustainability and profitability have to be explored case by case.

Mechanically recycled post industry plastic (PIR)

The source is traceable, and its chemical composition is constant. In principle it would be possible to manufacture a post industry fulfilling the VDI2017. However, no such grades are currently on the market*. Probably because of availability issues. It is very difficult to source large amounts of exactly one grades waste. Another topic could be the questionable sustainability impact, since one could argue that the waste producer should try to reduce and reuse its waste in its own production instead of manufacturing post industry grades from them.

Mechanically recycled post consumer plastic (PCR)

The great advantages regarding carbon neutrality and circularity, the reasonable price and the availability sounds all great, but can it fulfill the VDI2017 guideline? The default answer you will get, is No. But don’t be so sure about that. It was long the general opinion, that mechanically recycled plastics cannot be food approved. And yet we are seeing more and more food approved mechanically recycled plastics. Especially PET is abundant and very pure in the waste streams. That is also the first point to look for medical grade mechanically recycled plastic. Currently there are no mechanically recycled post-consumer medical grade plastics on the market*. But it wouldn’t be surprised if soon a solution would be available.

Conclusion

Medical grade plastics according to the VDI2017 are currently only available as chemically recycled plastics. PIR plastic and PCR plastic are both possible future solutions where PCR has a clear advantage on the availability. The number of sustainable solutions is increasing every year and it is a question of time when medical grade plastics are available broadly as recycled materials.

*To the best of the knowledge of the author at the time of publication