Introduction: Ozone (O3) is an allotropic form of oxygen (O2). At room temperature, it is a light blue gas with a special odor. Ozone exists mainly in the ozone layer in the lower stratosphere, 20 to 35 kilometers from the earth's surface. Under normal temperature and pressure, it has poor stability and can be decomposed into oxygen by itself. Ozone has the smell of grass. Inhaling a small amount is beneficial to the human body. Excessive inhalation will cause harm to human health.