Ozone is a non-toxic and safe gas. When the concentration is higher than 1.5ppm, ozone stimulates the human respiratory system. Therefore, the Ozone Association has formulated safety and health standards: (1ppm=1 mg/m3) International Ozone Association: 0.1ppm, contact 10 hours; United States: 0.1ppm, contact for 8 hours; Germany, France, Japan and other countries: 0.1ppm, contact for 10 hours; China: 0.15ppm, contact for 8 hours. The product of its concentration and contact time can be regarded as the reference point.
When the ozone concentration is 0.02ppm, people with agile sense of smell can detect it, which is called the sensory threshold. When the concentration is 0.15ppm, it is the olfactory threshold. Most people can smell it, which is also a hygiene standard point. When the concentration reaches 1-10ppm, it is called the stimulation range, and when the concentration is above 10ppm, it is the poisoning value.
People's perceived concentration of ozone is only 0.02-0.04ppm, which is still a certain distance from the safe concentration. The use of ozone to purify the air indoors has basically achieved the effect of disinfection when smelling the smell of ozone. At about 0.02ppm, the air will feel particularly fresh. The refreshing feeling in the air after a thunderstorm is due to the large amount of ozone and negative ions generated by lightning. Some scientists have concluded that if there is no ozone in nature, human beings will suffer many additional disasters, so the evaluation of ozone is "a god-sent purifier". Since the "discovery" of ozone, there has been no fatal accident due to ozone poisoning in the world.
The safe concentration of ozone stipulated by the Ministry of Health is 0.1ppm, the industrial hygiene standard is 0.15ppm, and the labor protection department stipulates that the work is allowed to work no more than 10 hours under the safe concentration. However, the ozone concentration that people can smell is generally 0.02ppm, which is far from safe. Due to the strong irritant of ozone, people have long avoided it when they feel unwell, so there is generally no poisoning during use.
Ozone is an unstable gas. Its half-life is only about 30 minutes. It does not need to be eliminated deliberately. At room temperature, it will exist for at most about 30 minutes, and then it will be reduced to oxygen. If you have to eliminate it, there are the following methods. First, let the air flow, dilute the ozone concentration, and finally achieve elimination. The second is heating. When the temperature reaches about 60 degrees Celsius, ozone will be quickly reduced to oxygen. The third is to use the strong oxidizing properties of ozone to release other substances that are prone to oxidation reactions to neutralize ozone. (It is more troublesome and the cost is high, so it is not worth promoting).