Formaldehyde fumigation disinfection method

Formaldehyde is an active alkylating agent, which is inactivated by alkylating amino groups, hydroxyl groups and sulfur groups on protein molecules of microorganisms and nucleic acids. The experiment shows that the inactivation rate of concentrated ammonia oxidation method is 73% under the conventional dosage. The bactericidal effect is 100%. Gaseous formaldehyde is effective in inactivating bacteria, and its gas production is positively related to its bactericidal ability. In a certain range, with the increase of dosage, the bactericidal effect of formaldehyde can be improved. The method of oxidizing concentrated ammonia water with formaldehyde is to inject enough formaldehyde and oxidant at one time, and through oxidation, high-concentration formaldehyde gas is released quickly, which increases the inactivation effect on microorganisms. After the fumigation time reaches 4 h, the concentrated ammonia reacts with the residual formaldehyde molecules in the oxidation reaction to generate a new substance methylamine. Methylamine is a non-toxic and non-irritating substance, which does not affect the sterilization effect of sterilized articles and can also reduce the harm of irritating gas to the health of medical staff. To sum up, the method of oxidizing concentrated ammonia water with formaldehyde is simple to operate and can avoid the harm to the health of medical staff. It is very popular and worthy of popularization and application. However, the correct method should be mastered when using, the dosage of formaldehyde is 320 ml/m3, the fumigation time is not less than 4 h, the ratio of concentrated ammonia water to formaldehyde is 1∶4, and fumigation is performed for 30 min after adding concentrated ammonia water. At the same time, it is necessary to plan the time to remove toxic substances. When the total opening time is 322 s, the effective disinfection time is 46 h. If it exceeds the total opening time or total disinfection time, it should be fumigated again.