Ozone poisoning is closely related to the duration and concentration of exposure. In China, the ozone concentration is set at 0.15 ppm, and symptoms may occur after 8 hours of continuous exposure, so the labor law stipulates that working at a safe concentration cannot exceed 10 hours. Ozone is a non-toxic gas with strong oxidizing properties and is normally used at low concentrations, which generally do not cause poisoning. Short-term inhalation of low concentrations of ozone may cause mild symptoms such as dryness of the mouth and throat, coughing and phlegm. Long-term direct exposure to high concentrations of ozone may cause the eyes, nose and lungs to be affected, along with symptoms such as loss of vision, headache, fatigue, coughing, chest tightness, chest pain and nausea, requiring immediate removal from the environment. After getting out of the ozone environment, you should promptly wash your nose and drink more warm water, which usually does not cause toxic reactions. Short-term oral and nasal mucous membrane irritation appears dry and usually returns to normal soon.