Pungent odor, detectable at 0.01 to 0.04 ppm; sharp disagreeable odor at 1 ppm

Extremely irritating to the eyes and respiratory tract; high acute toxicity. Reacts violently with many oxidizable organic and inorganic substances; may form shock-sensitive and highly explosive reaction products.

Ozone is a highly toxic gas that is extremely irritating to the eyes, mucous membranes, and respiratory tract. The characteristic odor of ozone can be detected below the permissible exposure limit, and this compound is therefore regarded to have adequate warning properties. However, at higher concentrations the ability to smell ozone may decrease. Inhalation of 1 ppm ozone may cause headaches and irritation of the upper and lower respiratory tract. The first symptoms of exposure include irritation of the eyes, dryness of throat, and coughing; these symptoms disappear after exposure ceases. Exposure at higher levels may lead to lacrimation, vomiting, upset stomach, labored breathing, lowering of pulse rate and blood pressure, lung congestion, tightness in the chest, and pulmonary edema, which can be fatal. Exposure to 100 ppm of ozone for 1 hour can be lethal to humans.

Animal studies indicate that chronic exposure to ozone may result in pulmonary damage, leading to chronic lung impairment. Continual daily exposure to ozone can cause premature aging.

Ozone by itself is not flammable. Liquid ozone and concentrated solutions are extremely hazardous and can explode on warming or when shocked.

Ozone is a powerful oxidant and can react explosively with readily oxidizable substances and reducing agents. Explosions can occur when ozone is exposed to bromine, hydrogen bromide, hydrogen iodide, nitrogen oxides, lithium aluminum hydride, metal hydrides, hydrazine, alkyl metals, stilbene, ammonia, arsine, and phosphine. Ozone reacts with alkenes and other unsaturated organic compounds to form ozonides, many of which are