MICROBIOLOGIC EVALUATION OF A HYDROGEN-PEROXIDE STERILIZATION SYSTEM

The reliability of chemical sterilizers (acetone and/or 30-percent hyd rogen peroxide at 25 degrees C and at 60 degrees C) was tested against Bacillus subtilis inoculated onto glass slides, commercial biological indicator discs (Bacillus stearothermophilus and B. subtilis), and B. subtilis spore survival. Acetone alone was not sporicidal. Hydrogen-p eroxide-sterilized glass slides were sterile after 5 minutes. The indi cator discs required 25 minutes at 25 degrees C, and less than 3 minut es at 60 degrees C (P < .0001). The D Value of B. subtilis in 27-perce nt hydrogen peroxide at 25 degrees C is 2 minutes, with z values of 22 degrees C and 26 degrees C at 25 degrees C and 40 degrees C, respecti vely For delicate instruments, a 30-percent peroxide solution followed by an acetone rinse provides an effective alternative to classic heat sterilization.