The methods we are familiar with in our daily life are ultraviolet irradiation, chemical disinfectant spray and so on. However, because ultraviolet radiation needs to directly irradiate the surface or gas of the object to be sterilized, the method of gas fumigation is basically used in the disinfection and sterilization of high-level biosafety laboratories.
The sterilant selected for gas fumigation is exquisite, and the common ones are formaldehyde, hydrogen peroxide, chlorine dioxide and so on.
- Formaldehyde
The disinfection effect of formaldehyde gas is greatly affected by the ambient temperature and humidity, and the temperature and humidity should be strictly controlled within the specified range during disinfection. At temperatures higher than 20°C, formaldehyde gas can kill all microorganisms and their spores, but has no inactivation on prion proteins. Formaldehyde disinfection takes a relatively long time and requires a relative humidity of about 70%.
Formaldehyde fumigation has become a common disinfection and sterilization method in China because of its advantages of broad-spectrum sterilization, convenient use and low price.
However, due to the pungent odor of formaldehyde, its gas will irritate the eyes and mucous membranes, and it has been confirmed to have a carcinogenic risk. After disinfection, it needs to be neutralized, and then exhausted and ventilated. Because formaldehyde will remain after disinfection, pay attention to wiping to remove objects Trace residues on the surface. - Chlorine dioxide
Chlorine dioxide is different from general chlorine-containing disinfectants. It mainly exerts its disinfection effect through oxidation rather than chlorination, thereby avoiding the production of organic chlorides during the disinfection process. It has the characteristics that the bleaching effect and the disinfection effect are greatly affected by organic matter. - Hydrogen peroxide
Hydrogen peroxide has the characteristics of broad-spectrum, high-efficiency, quick-acting, non-toxic, corrosive to metals and fabrics, greatly affected by organic substances, good stability of pure products, and unstable dilution. Other ingredients are often added to existing products to stabilize hydrogen peroxide, enhance its bactericidal effect and reduce its corrosivity. The main advantages of hydrogen peroxide disinfection are drying, rapid action, non-toxicity, and no residue.
The current common airtight fumigation mode actually has certain problems. When airtight fumigation is used, if there are multiple core workshops, when there are no multiple disinfection equipments that can be disinfected at the same time, the disinfection process, after disinfection and non-sterilization There is a risk of rooms contaminating each other, and even contaminating the surrounding environment such as suspended ceilings and peripheral corridors.
Therefore, many companies have begun to use the new disinfection and sterilization mode. The dry mist hydrogen peroxide sterilizer manufacturer recommends the use of dry mist hydrogen peroxide sterilization technology.
This technology has been used in European laboratory environmental disinfection for nearly 20 years. Especially in recent years, hydrogen peroxide sterilization technology has developed rapidly in the environment where the European Union restricts the use of formaldehyde for space sterilization.
First of all, on the sterilant, as mentioned above, hydrogen peroxide has the characteristics of broad spectrum, high efficiency, quick effect and non-toxicity, but hydrogen peroxide will corrode metals and fabrics. The dry mist is a water mist particle larger than 2.5 microns and less than 10 microns. It has a characteristic that the droplets will bounce back after contacting the surface without breaking and thus moistening the surface, thus solving the problem of hydrogen peroxide corroding metals and fabrics. It is one of the pioneering sterilization methods.