Sterilisation and virus sars-cov-2 inactivation in personal protective equipment with supercritical co2

Abstract

The different elements of the sanitary personal protection equipment (PPE) were subjected to sterilisation using supercritical CO2 at 40 ˚C and 95 bar, supplemented with several additives. Strips with spores of Geobacillus stearothermophilus and Bacillus atrophaeus were used as bioindicators. Supercritical CO2 alone or mixed with water (0.3 %) failed to inactivate them. Small additions of H2O2, peracetic acid, acetic anhydride, ethanol or peppermint essential oil were also ineffective. It was only possible to achieve the sterility with mixtures of 500 ppmv water + 15 ppmv H2O2 + 1000 ppmv acetic anhydride, or with 500 ppmv water + 15 ppmv H2O2 + 50 ppmv peracetic acid. There was an evident synergy related to the different action that each additive provided. The inactivation of the SARS-CoV-2 coronavirus was also tested. No virus viability or replication capacity was observed after the treatment for 5 min with CO2 at 100 bar, and cool conditions. No additives were required. Also, the inactivation was equal in all the elements of the PPE. That is to say, the support did not influence the death of the virus. The scCO2 sterilisation could be established as a new low temperature sterilisation technique for which there is a growing market.