Verification of ozone disinfection in clean rooms (areas)

clean room(district)Verification of Ozone Disinfection
1. Ozone disinfection method
Ozone disinfection in clean rooms (areas) is generally divided into systematic disinfection and local disinfection, such as individual buffer rooms, transfer rooms, etc.
(1) Disinfect the room through an air purification system (HVAC). Select the appropriate ozone generator based on the volume of the clean room (area), the volume (or air volume) of the HVAC system's air ducts, and the ozone sterilization efficiency. The host can be placed in a suitable position on the main supply or return air duct of the air conditioning system, and the power control system can be placed in the computer room. Close the corresponding fresh air inlet and return air discharge valves during disinfection, allowing the air in the entire disinfected clean area to pass through the purification systemThe air duct forms a cycle, and the ozone generator starts working. If air sterilization is done daily, it can generally be turned on for 1-1.5 hours; if ozone is used instead of chemical reagents to fumigate surfaces, walls, floors, and equipment every week, it can generally be turned on for 2-2.5 hours. Its advantage is that there is no need to add any disinfection equipment in the disinfected room, which can meet the requirements of the standard and maintain a good working environment. It can also be directly installed in air treatment equipment, making the installation and maintenance of ozone generators simpler and more convenient.

(2) The ozone generator is directly placed in the room for use.

2. Calculation of ozone generator disinfection
On the premise of selecting a suitable ozone generator, the volume of the clean room (area) is set to V1, the volume of the HVAC system duct is set to V2, and V3 is the ozone consumption of the fresh air supplemented to maintain positive pressure in the clean area.
The volume of disinfection space is:
V＝ V1+ V2+V3
The determination of V3 in the formula is based on disinfection practice, and a reliable empirical formula is summarized as follows:
V=total circulating air volume of HVAC system (m3/h) × 25% (assuming a fresh air supplement of 25%) × 10% (the amount of fresh air required to maintain positive pressure in the clean area) × 37.75% (calculate the budget value for applying ozone half attenuation rate)
Namely: V ≈ total air volume of the circulation system × 0.944%

3. Principle of ozone disinfection

Ozone (O)₃）The disinfection principle of ozone is that its molecular structure is unstable at room temperature and atmospheric pressure, and it quickly decomposes into oxygen (O) on its own₂）And with a single oxygen atom (O), the latter has strong activity and is harmful to bacteriaOxidation can oxidize and decompose the enzymes necessary for the internal oxidation of glucose in bacteria, thereby destroying their cell membranes and killing them. The excess oxygen atoms will recombine on their own to form universal oxygen molecules (O)₂）There are no harmful residues, hence it is called a pollution-free disinfectant. Ozone not only has the ability to kill various bacteria (including hepatitis virus, Escherichia coli, Pseudomonas aeruginosa, and miscellaneous bacteria), but also is effective in killing mold.

The main raw materials for producing ozone are air and electricity, which are generally obtained through high-frequency ozone generators (electronic disinfectors). Simply place the ozone generator in the room during disinfection. The concentration of ozone used for disinfection in the air is very low, only a few parts per million, which can be calculated based on the volume of the room and the ozone production of the ozone generator.


4. Verification points for ozone disinfection in clean rooms (areas)
The technical indicators of the ozone generator that need to be confirmed and calibrated in the verification of ozone disinfection effect mainly include ozone production, ozone concentration, and time timer, and the disinfection time is determined by checking the number of bacteria.

Knowledge extension:Ozone sterilization time and concentration requirements for microbiology laboratory

Ozone concentration requirements

Surface disinfection of objects: For surface disinfection of objects, it is generally required that the ozone concentration is 60mg/m ³, the relative humidity is ≥ 70%, and the disinfection effect can only be achieved after 60 to 120 minutes of exposure.

For the disinfection of biological laboratories, choose a matching ozone generator based on the size of the laboratory, with a disinfection time of 1-1.5 hours. For example, a biological laboratory with an area of 40 square meters requires an ozone disinfection concentration exceeding 20ppm. Tonglin recommends a 100g/h ozone generator (with built-in oxygen generator), paired with a chiller and an electrical box. During ozone disinfection, an ozone detector is used to detect the disinfection concentration in real time. After disinfection, the disinfection records are checked, and the ozone concentration is above 20ppm, meeting the disinfection requirements.

Safety considerations: It should be noted that high concentrations of ozone can irritate the respiratory tract, causing symptoms such as sore throat, chest tightness, cough, and toxic pulmonary edema. Therefore, when ozone disinfection is used, people must leave the disinfection and sterilization environment, and can enter the environment after disinfection when the ozone smell is not heard (about 30 minutes after the end of disinfection and sterilization).

Ozone depletion coefficient: When calculating the total amount of ozone used, the depletion coefficient of ozone needs to be considered. Usually, S=60% is taken, which means that the concentration of ozone will gradually decrease over time.

Ozone sterilization in microbiology laboratories is generally recommended to be carried out for 1-1.5 hours, with a concentration requirement of 20-60mg/m ³. However, the specific concentration and time requirements still need to be adjusted according to the actual situation of the laboratory and relevant standards. During use, attention should be paid to safety and the degradation pattern of ozone to ensure the desired disinfection effect.

That's allVerification of ozone disinfection in clean rooms (areas)For more information, please consult us or leave a message online, and we will contact you as soon as possible.