PVC is a controversial material and has been so for many years. And despite the fact that when PVC was introduced in the medical area in the 1960s the treatment of patients was revolutionised, the criticism has continued. The criticism is mostly regarding the use of the phthalate DEHP as a plasticiser, but the fact that single-use PVC devices must be incinerated after use also has been a concern. Even though some of the concerns are well founded (ie. the use of DEHP in vulnerable applications), most of the criticism is based on antiquated data, and it is my hope that on this website, I will be able to shed light on some of these misunderstandings by answering specific questions on the use of PVC in medical devices.

Medical devices manufactured in PVC and other plastics are characterised by a rather complex value chain with many different technologies, specialities and knowledge areas involved. If you for example take a urinebag manufactured in PVC there are many kind of industries involved, from the production of the raw material to the moment the nurse installs the bag on the bedside of the patient.

First of all you have the manufacturers of the PVC raw material – the resin, which is of no value without the additives (plasticisers, stabilisers etc.) produced by different companies. When the additives are mixed with the resin, you get the compound, which is made by the compounder. Now compounded, the compound is typically purchased by the converter who makes the tubing, the bag etc. All the companies mentioned so far are not necessarily involved in the medical industry only. They produce products to many other industry sectors.

The medical device manufacturer then purchases the extruded tubing and the calendered bag from their subcontractor – the converter. Then company then manufactures the final product. Finally the distributor comes into the picture and then the device ends up at the hospital to be used in the treatment of a patient.

The two main application areas for medical approved PVC compounds are flexible containers and tubing. Examples are containers used for blood and blood components for urine or for colostomy products and tubing used for blood taking and blood giving sets, catheters, heart-lung bypass sets and haemodialysis sets. In Europe the consumption of PVC for medical devices is approximately 85.000 tons. This amount represents less than 1% of the total PVC demand.

It is difficult for me to recommend specific companies on a blog such as this because of commercial sensitivities. However, I am aware of the phenomenon of water blush in film applications and bag clearing effects and there are companies who I am confident could supply appropriate compounds and recommended procedures to ameliorate such a phenomenon. Therefore I would recommend you attempt to make contact with compound manufacturers and request their help.

I am not sure that I fully understand your question, so please feel free to return to specifically highlight the parts of ISO 10993 which you feel PVC would not meet. In our experience PVC can meet all the relevant parts of ISO 10993, assuming that its use is what it is intended i.e. single use disposable applications. Whilst it is true that some PVC controls are used as positive controls i.e. “failure” these have been specifically designed as such as positive samples to give a cytotoxic response i.e. tin-impregnated strips for use specifically with the ISO 10993-Part 5 methodology. Flexible PVC formulations that were tin-impregnated would not be used in flexible PVC medical devices.

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