Safe ozone concentration
a. People are allowed to be exposed to ozone concentration less than 0.2mg/m3.
b. Hygiene standard of ozone industry
International Ozone Association: 0.1PPM (0.2mg/m3), contact for 10 hours;
United States: 0.1PPM (0.2mg/m3), contact for 8 hours
Germany, France, Japan: 0.1PPM (0.2mg/m3)
China: 0.15PPM (0.3mg/m3)
c. Ozone leakage of household ozone disinfection cabinet should not exceed 0.2mg/m3 (1.5 meters) , and residual concentration after one cycle must be less than 0.2mg/m3.
d. The animal experiment showed that the starting point for ozone toxicity is 0.3PPM（0.6mg/m3), while ozone concentration that one can smell in the air is 0.02-0.04PPM. According to the experiment result of ozone on pulmonary toxicity, it shows that the upper limit for allowable ozone concentration is 1.5-2.0PPM. The Ministry of health provides the maximum ozone concentration is 0.2mg/m3
Application concentration in air:
a. Odor removal and sterilization: It requires low ozone concentration such as 0.5PPM, while for surface disinfection (killing microorganisms and removal of microbial contamination, it is required to improve the concentration of tens of times.
b. Generally the required ozone concentration for air application should be between 1 and 100PPM.
c.The disinfection effect is better when in low temperature and high humidity environment. Especially when the relative humidity less than 45%, there is almost no killing effect on the suspended microorganism in the air. At 60%, it gradually increases up to the maximum value when humidity reaches 95%.
d. For food processing plant, ozone concentration 0.5-1.0PPM could kill 80% of the natural bacteria in the air.
e. For cold storage room, the required ozone concentration is 6-10PPM. After being off for 24 hours, the bacteria killing rate is about 90% and mold killing rate about 80%.
f. During fruit storage, ozone concentration of 2-3PPM could inhibit the growth of mould so as to extend storage period.
Application concentration in water:
a. Ozone concentration in water is between 0.1mg/L and 10mg/L. Low value as the minimum concentration for water disinfection and high value as the value of ozone water disinfectant.
b. For tap water purification, the international standard for the solubility is 0.4mg/L. Keeping contact for 4 minutes and maintaining ozone concentration value between 0.1-0.5mg/L for 5 to 10 minutes could achieve the purpose of disinfection.
c. Ozone water disinfection is rapid and it could occur in an instant. Once the ozone concentration in water reaches a certain value, it could kill the bacteria in 0.5-1 minutes. When ozone concentration reaches 4mg/L, within 1 minute it could kill hepatitis B virus completely.
d. Under the condition of 20℃, when ozone concentration level is 0.43mg/L, it can kill escherichia coli; under the condition of 10℃, 0.36mg/L can kill all the bacteria.
e. When ozone concentration is 0.25-38mg/L, it only needs a few seconds or minutes to completely kill HAV.
f. Ozone solubility in mineral water 0.4-0.5 mg/L could meet the requirements for sterilization. Ozone dosage is 1.5-2.0mg/L.