EXPERIMENTAL STUDY ON GERMICIDAL EFFICACY OF GLUTARALDEHYDE DISINFECTION SOLUTION AND ITS INFLUENTIAL FACTORS

Objective To study the technical requirement of sanitary quality of glutaraldehyde disinfection solution in order to provide basis for drawing up the universal standard of glutaraldehyde disinfectant. Methods Carrier immersion quantitative germicidal test, qualitative germicidal test and physicochemical analysis were used to carry out laboratory observation on germicidal efficacy of glutaraldehyde solution in common use and its influential factors. Results At room temperature, the average killing logarithm values of Mycobacteria chelonei subsp. abscessus and spores of Bacillus subtilis var. niger on stainless steel round coupons exposed to 20 g/L glutaraldehyde solution prepared from medical-grade glutaraldehyde raw material for 5 min and 60 min respectively were3.00 and they were completely killed after exposure for 2 h. After the solution was continuously used for 14 days, 5 h was required for completely killing the bacterial spores. Under the conditions specified by the experiment, the germicidal efficacy increased with increasing glutaraldehyde concentration and prolonging of the exposure time. When the glutaraldehyde raw material was changed from medical grade to biochemical grade, its germicidal efficacy decreased. Non-ionic and cation surfactants had synergetic effect on germicidal efficacy of glutaraldehyde. After 20 g/L glutaraldehyde solution in airtight packing was stored at 37℃ for 90 days, its content decreased by 10.0%. After the activated 20 g/L glutaraldehyde solution was stored at room temperature for 28 days, its content decreased by 10.0% and its pH value had no obvious change. Conclusion 20 g/L glutaraldehyde solution has reliable germicidal efficacy and stable property. The germicidal efficacy of glutaraldehyde is influenced by the factors such as grade of its raw material, ingredients of its formula, concentration and contact time.