Gas-plasma sterilization:: relative efficacy of the hydrogen peroxide phase compared with that of the plasma phase

Recent modifications specified in the European Pharmacopoeia IIIrd Edition (1 January 1997) have led us to investigate the sensitivity of Bacillus stearothermophilus ATCC 7953, a sporulated bacterial species now used instead of Bacillus subtilis var niger ATCC 9372 as a reference in peroxide sterilization. Inactivation kinetic studies have shown that this choice is well founded and also indicate that inherent efficacy of the STERRAD(R) 100 gas-plasma process is above all due to hydrogen peroxide. The ionization obtained during the plasma phase is validated in its role of a residue detoxifying process, without any sporicidal effect. (C) 1998 Elsevier Science B.V.