The Ins and Outs of Plastics in the Medical Industry

By Mauricio Acosta Diaz & David Mustoe

As the years have gone by, the use of plastics in medical devices has become so advanced that they are a necessity in the vast majority of procedures. These plastics have been chemically modified for years on end, and they have nearly perfected every variation of plastic used from a chemical standpoint. However, there is still information, good and bad, regarding the use of plastics in the medical field that the public may not be aware of.

GENERAL PROs and CONs

          First off, the pros. Medical plastics of all variations are very versatile and can be used to accommodate seemingly any type of procedure. One such variant is polycarbonates, which are all manufactured under a physician's license, and need to pass various tests (like durability and biocompatibility) provided by regulatory agencies to be used in procedures. Additionally, these plastics are beginning to be more sustainable from a chemical standpoint to where they are all easily able to be recycled, refurbished, and reused, thus limiting the need to create more plastic, and saving 40-60% compared to brand new, unused parts.

Medical devices, while very functionally sound, are not always designed the best possible way. For example, some devices are petroleum based, when they could be replaced with a bio-based, less harmful material. Additionally, some medical devices use multiple different types of plastic and other additives which leads to a painful recycling and refurbishing process. The last main flaw is the packaging and distribution of the devices. Often, the packaging materials and delivery of said materials creates more of an environmental burden than the device itself.

HOW IS EACH POLYMER USED?

Polycarbonates are used in plastic eyewear and protective gear for doctors. They are useful due to their moldability and ability to form at room temperature without cracking. Also worth noting is that they are easily cleaned and maintained, which is why it is used in blood transferal. There are many other polycarbonate applications as well explained at this link here. 

PET is used in prosthetic-based applications due to its ability to not degrade in the human body. PET is extremely impact and chemical resistant, making it the “jack of all trades” in the world of medical plastics. PET has helped immensely by giving prosthetic parts and builds to the less fortunate animals. A main ingredient in these builds is HDPE, a variant of PE, due to its high durability and lightweight. More
information on that is here.

PP (polypropylene) is cost effective and reusable. Syringes are a common application where PP is used. It is also used when a steam-sterilized medical device is necessary due to its low moisture absorption and its ability to deflect dangerous bacteria. Lastly, it is used in prescription bottles and clear bags. In general, polypropylene is used in extreme environments as it is very corrosive and chemical resistant.

HOW DO WE RECYCLE POLYCARBONATES NOW?

According to Brenner (2016), the method we use to recycle polycarbonates is via mechanical recycling. Mechanical recycling is one of the most energy efficient means of recycling that is known. The process of recycling this plastic entails sorting, shredding, washing, then granulating. After granulation, the plastic is distributed to manufacturers again for them to use as they prefer.

In hospitals, Brenner (2016), says that they are increasing the amount of medical plastics recycled by simply separating the plastic and non-plastic waste in different bins. It was also found that there is an internal issue within hospitals, where they do not train their employees on proper medical waste disposal. This leads to issues such as putting trash in the wrong place such as red biohazard bags or recycling bins. Although we are on the right track there is still research to be done, and other alternatives to eliminate most of the waste in the medical industry.

ARE THESE PLASTICS SUSTAINABLE?

          While plastics do so much good in the present for the human population, are they sustainable? Most of these plastics are chemically sound and are designed for functionality and not sustainability. 

Single-use devices have their perks no doubt, and they are extremely reliable in the present because they are guaranteed to be clean and efficient every time. However, if these devices are not used to their limit, they are subject to being improperly disposed of, which leads to a myriad of different environmental issues. 

One solution is altering the disposal of these devices, and instead sending all plastics to a refurbishment center so they can reenter the hospital for reuse. Ideally, this refurbish center should be located inside hospitals so that there is no energy wasted on shipping out and bringing back these devices. If the devices are all locally managed and properly cleaned, it would severely decrease carbon emissions, which is inherently sustainable. A different solution to fixing these recycling concerns is being done today in Boulder County, Colorado.

Another consideration is the idea of limiting the diversity of materials in these devices. A good example of this is syringes, where PET and PP are both commonly used to make them. PET shines in the prosthetics and implant sector of plastics because of its durability and chemical resistance. Some studies have shown that PP used in hernia meshes can lead to additional medical complications like nausea, vomiting and constipation. 

PP is very effective in syringes however, so a solution would be to use solely PP in syringes, and to section off PET for certain applications where it thrives over other plastics. Furthermore, when these syringes are sent to be mechanically and chemically recycled, there are too many variations of plastic for one common device. This wastes energy, as it is difficult to separate different materials of plastic. If syringes were solely PP however, this would significantly speed up the recycling process, because recycling firms would know exactly what to do with a syringe, thus limiting the need to implement sorting technology.

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