Comparison on Safety Concern Among Gamma-Ray, Autoclave and Ethylene Oxide Gas Sterilizations of Thermosetting Polyurethane

Abstract

Copyright: © 2014 Shintani H. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Sterilization of polyurethane (PU) produces 4,4’-methylenedianiline (MDA), a known carcinogen, and various others including hydrophilic and hydrophobic compounds. The relationships between PU components and MDA formation by several methods of sterilization were confirmed using thermosetting PU. Specimens of PU fabricated from different combination of isocyanates and polyols were obtained from dialyzers (detailed omitted in this editorial). The molecular weight of the particular poluol was found to influence the production of MDA by sterilization. Sterilization also produced many unidentified compounds. MDA production was not always associated with the production of the other compounds. Compared with gamma-ray irradiation sterilization, ethylene oxide gas (EOG) sterilization, and autoclave sterilization, gamma-ray irradiation sterilization produced most MDA (Figure 1). This phenomenon was significant for PU produced from smaller molecular weight polyols. The combination of autoclave sterilization and a PU produced from a larger molecular weight polyols is recommended to minimize the production of potentially toxic compounds. Of the techniques studied, EOG sterilization produced the least amounts of MDA and the other compounds, but the residue of EOG is itself problematic. Sterilization produced more MDA from PUs fabricated with smaller-molecularweight polyols than from PUs fabricated from larger-molecular-weight polyols.