ABSTRACT

The purpose of the study was establishing whether the size of the load - that is the degree of filling of sterilizer chamber with medical instruments - could have an effect on the time needed for eradication of all microorganisms subjected to the action of ethylene oxide. The test organism used was the strain of Bacillus subtilis var. niger ATTC 9372. Tests were prepared with about 3.6 x 106 spores per one test. The tested samples were exposed to ethylene oxide at concentration of 750 mg/1, at 50-80°C, at 40% humidity during 30, 60, 120, 180, 240 and 300 minutes in three variants:
- in empty sterlizer chamber
- im chamber loaded with plastic objects (polyethylene and polypropylene) - 600 g weight
- in chamber with similar load weighing 1200 g.
The obtained results showed that the degree of filling of sterilizer chamber influenced the efficiency of gas sterilization with ethylene oxide. The effectiveness of each sterilization process with ethylene oxide should be controlled using biological indicators.