Study On The Sterilization Effect And Mechanism Of Slightly Acidic Hypochlorous Acid Disinfectant

Healthcare Associated Infections have increasingly become a public health issue threatening global human health,and it is essential to adopt efficient and convenient disinfection measures.As a new type of sterilization technology that is safe,efficient,cheap and easy to obtain,the disinfectant generator has received widespread attention.Although the traditional chemical disinfection method has low operating cost and is easy to implement,it is not in line with the vision of public health environment development because of its poor safety and easy production of toxic by-products that harm human health and the environment.In order to make up for the shortcomings of current disinfection methods,this paper designs a new type of slightly acidic hypochlorous acid disinfectant generator,which uses sodium hypochlorite and hydrochloric acid as raw materials to produce slightly acidic hypochlorous acid disinfectant,and its performance and mechanism are studied.Considering the instability of hypochlorous acid,in order to extend the shelf life of hypochlorous acid disinfectant,sodium silicate and sodium carbonate are used as stabilizers,and 15 m L sodium silicate and 20 m L sodium carbonate are added to 200 m L disinfectant to disinfect,the stability of the liquid is improved by 5.96 times.In order to investigate the corrosiveness of the disinfectant produced by the generator to metals,the effect of killing bacteria and viruses,and the safety,it was evaluated according to the "Disinfection Technical Specifications" promulgated by the Ministry of Health of the People's Republic of China.The results show that the slightly acidic hypochlorous acid disinfectant is basically non-corrosive to stainless steel,slightly corrosive to aluminum,and moderately corrosive to carbon steel and copper;the disinfectant with an effective chlorine content of 250 ppm is harmful to Staphylococcus aureus and large intestine.The logarithmic values of killing Bacillus and Pseudomonas aeruginosa are both?5.00,the logarithmic values of killing Candida albicans are ?4.00,and more than 98% of Bacillus subtilis black var.spores and methicillin-resistant golden yellow grapes can be killed For cocci,the average logarithmic value of inactivation of PV-I and Echo11 viruses is greater than 4.00,all reaching the standard.The disinfectant solution containing 250 mg/L available chlorine content was applied to Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans for 5minutes.The former three logarithm inactivation value ? 5.00,the latter logarithm inactivation value? 4.00,and can kill more than 98 % Of Bacillus subtilis var.nier and methicillin-resistant Staphylococcus aureus.The average logarithmic value of the disinfectant for PV-I and Echo11 virus inactivation is greater than 4.00,which meets the standard.Rabbits and mice were selected as experimental animals,and the safety of the disinfectant was evaluated by the methods of mouse bone marrow polychromatic erythrocyte micronucleus test,in vitro mammalian cell chromosomal aberration test,acute inhalation toxicity test and skin irritation test.The results show that the disinfectant has no genetic toxicity in vivo;it does not show teratogenicity to mammalian cells in vitro;the toxicity of the disinfectant to female male mice is greater than 5000 mg/kg body weight,which can be determined to be a non-toxic disinfectant;In the irritation test,the rabbit's highest skin irritation index was 0.25,indicating that the disinfectant was non-irritating.Combined with the Chick-Watson disinfection kinetics model,the effects of pH,temperature,initial bacterial concentration,and organic matter on the sterilization effect of slightly acidic hypochlorous acid disinfectant were analyzed.The bactericidal mechanism of the disinfectant was investigated by detecting the permeability of the cell plasma membrane,the relative activity of TTCdehydrogenase,intracellular potassium leakage,electrical conductivity,protein leakage,and cell surface ultrastructure.The results show that pH,temperature,and organic have a greater impact on the efficiency of the disinfectant to inactivate microorganisms,while the initial bacterial concentration has a small effect.The disinfectant changes the permeability of the bacterial cell membrane,destroys the bacterial cell membrane structure and functional enzymes,and releases key nuclear substances in the cell to cause death.