EXPERIMENTAL OBSERVATION ON GERMICIDAL EFFICACY AND TOXICITY OF A COMPOUND DISINFECTANT

A compound disinfectant contains chitin,lysozyme and polyhexamethylene guanidine as the germicidal components.In order to observe its germicidal efficacy and toxicity,carrier quantitative germicidal test and animal toxicity test were used to carry out laboratory study.Results: The killing rates of Escherichia coli and Staphylococcus aureus on cloth strips exposed to 3000 mg/L dilute solution of the stock solution of the disinfectant for 5 min and Candida albicans on cloth strip exposed for 10 min were 99.99%.After its stock solution in air-tight condition was stored at 37℃ for 90 days,its efficacy in killing S.aureus and C.albicans essentially did not decrease.The bacteria suspension containing 50%(v/v) calf serum did not obviously influence its germicidal efficacy.Its mouse oral LD_(50) was 5000 mg/kg and its cumulative coefficient K was 5.The rabbit skin irritation score of its stock solution was 0 and eye irritation score was 3.0.The result of mouse bone marrow polychromatic erythrocyte micronucleus test for this disinfectant solution was negative and the sperm malformation test was also negative.Immersion in its stock solution for 72 h did not cause corrosion of stainless steel and copper and essentially did not cause corrosion of carbon steel and aluminum.Conclusion: The compound disinfectant has good efficacy in killing vegetative forms of bacteria and fungi.It belongs to practically non-toxic class,has weak cumulative toxicity and is non-irritating to skin,slightly irritating to eye.It is stable and low corrosive.