Approvals for medical goods both in Europe and the USA cover exclusively finished products. In the EU in addition to Directive 93/42/EEC there are some national regulations (e.g., in Germany the “Medizinproduktegesetz”) for the respective member country which must be followed.

Fig. 3 – TPU for nonwoven fabrics for gowns, drapery, and tubing.

For a new application in the EU, it is a precondition that the manufacturer of the product obtains a CE authorization involving biocompatibility testing according to EN ISO 10993 “Biological assessment of Medical Products”. This standard covers a number of test procedures related to the specific application and body contact time. According to experience from tests on injection molded plates, it is most likely that finished products made from Elastollan 1100 types without flame retardant additives or plasticizer will fulfill the requirements for irritation, sensitization, and cytotoxicity, assuming that the materials are correctly processed, and providing no unacceptable additives are included. This must, however, be confirmed by an authorized laboratory.

TPU is not suitable for articles for implantation, blood-bags, containers for liquid medicines or other liquids that are intended for transfer to the human body, nor for articles that could come into contact with saliva for longer time. A formulation of a transparent, plasticizer- free 70 Shore A material is available under the name Elastollan 1170A. The Cytotoxicity Assay in vitro (ISO 10993) is officially confirmed, as well as for the 80 Shore A material Elastollan 1180A. An USP class VI-classification is available for Elastollan 1185A and WY1140 (polyether with UV). For these reasons, more and more applications with TPU in medical segments are provided.

Examples of medical TPU applications include devices used for diagnostic, anesthesia and artificial respiration, as well as healthcare mattresses, dental materials, compression stockings, medical instrument cables, gel shoe orthotics, and wound dressings. (See Figure 3)

Regulations in USA: The additives and raw materials (excluding stabilizers) that are used to manufacture above mentioned Elastollan grades are listed in the Code of Federal Regulations by FDA, Title 21 §177.2600 “Rubber Articles Intended for Repeated Use” in the latest version dated January 4, 2011. The antioxidant stabilizers which are included are listed in § 178.2010 “Antioxidants and Stabilizers for Polymers”.

Regulations in Germany and European Community (EC): The mono meric raw materials and additives which are used for manufacturing the above products are listed in the “Bedarfsgegenstän - deverordnung” dated December 23, 1997, and last updated February 7, 2011. The monomeric raw materials are also listed in Chapter 2 of Recommendation XXXIX of BfR, last updated January 1, 2010, which covers articles manufactured from polyure thane. The used monomeric raw materials and additives are listed in Annex I of Regulation (EU) 10/2011.

Requirements for Food Contact Applications: Based on experience with food contact articles made of above described materials, it can be expected that articles will be in accordance with § 2 chapter 6 (1.) of “Lebensmittel-, Bedarfsgegenstände- und Futtergesetzbuch” for contact with dry foodstuff ( excluding packaging materials) and for contact with wet foodstuff for a maximum period of 10 minutes. Generally application simulating testing, in accordance with regulations in EU (e.g., Regulation (EU) 10/2011) has to demonstrate that global migration, specific migration, and other restrictions for substances does not exceed allowed quantities. Among others it has to be proven that primary amines are not detectable (BfR-Recommendation XXXIX, Nr. 3.1; Regulation (EU) 10/2011, Annex II). It is also a requirement that commodities shall not influence appearance, taste, or odor of the foodstuff. The compliance with legal requirements and generally accepted standards for consumer protection has to be proven for the specific application using the final article.

This article was written by Sarah E. Westerdale, Market Manager - Wire & Cable, Distribution, BASF Corporation, Wyandotte, MI. For more information, Click Here 

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Medical Design Briefs Magazine

This article first appeared in the June, 2013 issue of Medical Design Briefs Magazine.

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