STUDY ON FACTORS INFLUENCING GERMICIDAL EFFICACY OF COMPOUND GLUTARALDEHYDE DISINFECTANT

Objective To study the factors influencing germicidal efficacy of compound glutaraldehyde disinfectant.Methods Suspension quantitative germicidal tests were used to observe the influential factors such as temperature,pH value and organic substance.Results The average killing logarithm values of spores of Bacillus subtilis var.niger exposed to the original disinfectant solution containing glutaraldehyde 19200 mg/L for 2 h was 5.27.When the temperature during exposure was reduced from 30℃ to 10℃,the average killing logarithm value of bacterial spores exposed to the original disinfectant solution for 1 h was reduced from 4.23 to 3.26.When the pH value of the original disinfectant solution increased from 4.0 to 8.0,the average killing logarithm value of the bacterial spores exposed to the disinfectant solution for 3 h was increased from 0.97 to 8.40.Adding 50% calf serum to the bacterial suspension slightly influenced the germicidal efficacy of the original disinfectant solution in killing the bacterial spores.Adding sodium nitrite or polyoxyethylene aliphatic alcohol ether to the disinfectant solution could obviously enhance its germicidal efficacy.Conclusion The germicidal efficacy of compound glutaraldehyde disinfectant could be enhanced by increasing temperature and pH value.Adding sodium nitrite or polyoxyethylene aliphatic alcohol ether has obvious synergetic effect.However,the organic substance can reduce the germicidal efficacy.