Experimental Study On A Foam Aerosol Disinfectant Of Hydrogen Peroxide

Hydrogen peroxide is a high-efficacy oxidation disinfectant, with strong broad-spectrum biocidal efficacy and no decomposed toxicity. Lately, hydrogen peroxide has turned into the main environment-friendship disinfectant material. Foam aerosol disinfectants have many advantages, which can strongly adhere to slippy surface, with less drug dosage, no waterneeded. Foam preparations can be used especially to decontaminate the surfaces of vehicle, floor and building wall. It is reported that US army has developed foam disinfectant based on hydrogen peroxide, mainly for decontamination of chemical-biological warfare agents. But no report of similar product was found in China. We studied a foam disinfectant of hydrogen peroxide in the laboratory. Testing the foaming capability and stability (changed Warring Blender method), we screened the foam emulsification agent, foam stabilizer, and observed the compatible conditions of main ingredients. We established the final recipe of foam disinfectant of hydrogen peroxide by orthogonal design test, and then we studied the systematic germicidal regularity of foam disinfectant. The main results are as follows:Part Ⅰ: Study on the recipe screening of foam disinfectant of hydrogen peroxideWe preliminarily screened three foam emulsification agents and several foam stabilizers by changed Warring Blender method and chemical co-operation test. The result indicates: foam volume changes along with the concentration of foam emulsification agent, and the half-life time of foam changes along with the concentration of foam stabilizer. It was found that alkylbenzyldimethyl ammonium chloride and Arabia gel were the best choice. When the concentration of alkylbenzyldimethyl ammonium chloride is 4.8%, the foam volume is most; and when the concentration of Arabia gel is 0.3%, the half-life time of foam is 31minute(p<0. 05).We optimized the recipe by orthogonal design, and analyzed the foam volume by SAS 6.12 statistic software. The model is significant(p=0.0003) , alkylbenzyldimethyl ammonium chloride (factor A) , Arabia gel (factor B)and A*B are significant (p<0. 05), while hydrogen peroxide isn' t significant for foam volume (p=0. 8361) . Because the foam volume is the more the better, the final recipe will include 4.8% alkylbenzyldimethyl ammonium chloride and 0. 3% Arabia gel. Hydrogen peroxide is the main germicidal factor, so we should decide the final concentration of hydrogen peroxide according to the following germicidal efficacy.To observe the recipe' s sporicidal efficacy of Bacillus subtilis var. niger (ATCC9372)by carrier quantitative test, we prepared four recipes with different concentration of hydrogen peroxide and the same concentration of alkylbenzyldimethyl ammonium chloride , Arabia gel. The sporicidal test indicates: the efficacy was improved along with the increase of hydrogen peroxide concentration.Considering the hydrogen peroxide characters and actual appliance, we determined the final recipe as follows: 5.07% hydrogen peroxide, 4.8% alkylbenzyldimethyl ammonium chloride and 0. 3% Arabia gel. The new production of foam disinfectant is a hydrophilic emulsion , and its pH value is 4.81. The acceleration test indicates, after foam disinfectant left for 14 days at54 "C.the concentration reduction ratio of hydrogen peroxide is 3.35%. Part II: Study on germicidal regularity of foam disinfectantof hydrogen peroxideK Sporicidal kinetics of foam disinfectant of hydrogen peroxide we tested the disinfectant' s sporicidal kinetic process of the spores of Bacillus subtilis var.niger (ATCC9372)and Bacillus anthracis(vaccine) .The value of the nature logarithm of survival rate of spores and disinfecting time is linear kinetics, Ordering y the nature logarithm of survival rate of spores, when disinfecting the spores of Bacillus subtilis var. niger, the regression equation is y=-0.116478t (F=12. 816, p=0. 0373) , and the value of D(the time of killing the 90% spores) is 19.77 min; When disinfecting the Bacillus anthracis spores, the regression equation is y=-0. 298948t (F=62. 513, p=0. 0156), and the value of D is7.70min.At test temperature between 10~40"C, the germicidal efficacy of foam disinfectant is increased with the raise of temperature . At different temperature, the value of the nature logarithm of survival rate of spores of Bacillus subtilis var. nigerand disinfecting time is linear kinetics, Ordering y the nature logarithm of survival rate of spores of Bacillus subtilis var. niger, At 10 °C , the regression equation is y=-0. 016628t(F=10. 994, p=0. 0452), and the value of D isl38. 48min;At 20°C, the regression equation is y=-0. 106620t(F= 24.058 , p=0. 0162), and the value of D is 21.60min;At 30 °C the regression equation is y=-0.241754t(F=21.569, p=0. 0434), and the value of D is 9. 52min;At 40°C the regression equation is y= -0.431613t(F= 31.738 , p=0. 0301), and the value of D is 5. 33min.The value of the nature logarithm of D and disinfecting temperature is linear regression, Ordering y the nature logarithm of D, the regression equation is y=-0. 105879T+5. 629824(F=25.436,p=0.0371) , the value of Z (which is the temperature variety when the value of D changes ten times) is 9. 44°C, and the temperature coefficient Qt0 (which is the time variety ratio with 10°C rise in...