气体二氧化氯用于空间消毒的评价

目的用商品化的生物指示剂确定气体二氧化氯达到空间灭菌水平所需消毒参数，同时评价环境湿度、有机干扰物、物体表面材料对气体二氧化氯消毒效果的影响。方法采用商品化及自制的枯草芽孢杆菌黑色变种芽孢（以下简称“枯黑芽孢”）菌片作为生物指示剂，对气体二氧化氯在不同消毒参数及实验条件下对微环境实验室消毒效果进行定性评价。结果环境湿度升高，气体二氧化氯杀灭芽孢作用显著增强，但湿度过大时光滑表面容易结露，金属表面产生轻微的腐蚀。根据商品化生物指示剂显示可以判定300ppm气体二氧化氯消毒3h基本可以达到空间灭菌水平；牛血清白蛋白能够明显影响气体二氧化氯对枯黑芽孢的杀灭作用；300ppm气体二氧化氯消毒4h能够完全杀灭滤纸枯黑芽孢菌片，但1000ppm气体二氧化氯消毒4h仍不能将不锈钢菌片或棉布茵片完全杀灭。结论气体二氧化氯消毒时环境相对湿度控制在75％左右为宜；商品化的生物指示剂并不能完全准确地指示气体二氧化氯空间消毒结果，应根据消毒空间内物体表面材料的不同及有机干扰物的存在与否相应增加气体二氧化氯浓度及消毒时间。

Evaluation of gaseous chlorine dioxide fumigation for enclosed space decontamination

Objective To determine the fumigation parameters required for gaseous chlorine dioxide （CD） to sterilize space using commercially available bioindicators and to investigate the effect environmental humidity, organic burden and material types of contents surface on the results of gaseous chlorine CD for enclosed space biodecontamination. Methods Self-made or commercially available coupons inoculated with spores of Bacillus subtilis var niger（ATCC9372） were used as bioindicators to qualitatively evaluate the biodecontamination consequence of mieroenvironmental laboratories by gaseous CD with various fumigation parameters and under various experimental conditions. Results The ability of gaseous CD to inacti- vate spores was enhanced with environmental humidity. However, too high concentration vapor was liable to condense on the slick surface and there was a slight corrosion mark on the metal surface. According to the results indicated by commercially available bioindicators, enclosed space could be sterilized by 3 hours of fumigation of 300 parts per million volume （ppmv） gaseous CD. Albumin could well protect spores from gasous CD killing. 300 ppm gaseous CD fumigation for 4 hours could sterilize filter paper coupons, while 1000 ppm gaseous CD for 4 hours still failed to biodecontaminate steel coupons or cloth coupons completely. Conclusion The relative humidity of enclosed space should be maintained at about 75% for enclosed space fumigation with gaseous CD. Commercially available bioindieators fail to indicate accurately the decontamination of enclosed space with gaseous CD. CD concentration or docontamination time should be increased according to surface materi- al types and the absence or presence of organic burdens in disinfection objects in enclosed space.