4780 Ozone Ozone is a pale blue gas with a distinctively pungent smell. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges. It is present in low concentrations throughout the Earth's atmosphere. In total, ozone makes up only 0.6 ppm of the atmosphere. In standard conditions, ozone is a pale blue gas that condenses at progressively cryogenic temperatures to a dark blue liquid and finally a violet-black solid. Ozone is a powerful oxidant (far more so than oxygen gas) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 ppb. Ozone's odor is sharp, reminiscent of chlorine, and detectable by many people at concentrations of as little as 10 ppb in air. Ozone, along with reactive forms of oxygen such as superoxide, singlet oxygen, hydrogen peroxide, and hypochlorite ions, is naturally produced by white blood cells. The largest use of ozone is in the preparation of pharmaceuticals, synthetic lubricants, and many other commercially useful organic compounds. It can also be used for bleaching substances and for killing microorganisms in air and water sources. Many municipal drinking water systems kill bacteria with ozone instead of the more common chlorine. 10028-15-6 16206854 O3 47.998 Light blue gas. -251 °C Inhalation Ozone is a strong oxidant and reacts directly with organic double bonds. When ozone breaks down to dioxygen it gives rise to oxygen free radicals, which are highly reactive and capable of damaging many organic molecules. Moreover, it is believed that the powerful oxidizing properties of ozone may be a contributing factor of inflammation. When inhaled, ozone reacts with compounds lining the lungs to form specific, cholesterol-derived metabolites that are thought to facilitate the build-up and pathogenesis of atherosclerotic plaques. These metabolites have been confirmed as naturally occurring in human atherosclerotic arteries and are categorized into a class of secosterols termed atheronals, generated by ozonolysis of cholesterol's double bond to form a 5,6 secosterol. Ozone has also been shown to form the suspected carcinogen bromate when it is introduced to source water with high bromide concentrations. Studies have also demonstrated an increase in collagen, a structural protein involved in fibrosis, following prolonged ozone exposure. Acute and short-term exposure studies have demonstrated ozone’s effects on lung lipids which include an increase in arachidonic acid (a pro-inflammatory molecule). Ozone can spontaneously break down to dioxygen. Most inhaled ozone reacts with cellular lipids and forms lipid peroxides which are eventually eliminated in the feces. 0.1 to 1 umol/mol will cause acute toxic effects. 40 nmol/mol will cause long term lung problems. Pulmonary edema developed in welders who had a severe acute exposure to an estimated 9 ppm ozone plus other air pollutants. 50 ppm for 60 minutes is expected to be fatal to humans. No indication of carcinogenicity (not listed by IARC) (L135). Tests in mice found no carcinogenic effect (A15094). Produced by white blood cells, generated by lightning, photocopiers and UV light. Used as an industrial chemical in the preparation of pharmaceuticals, synthetic lubricants. Used for bleaching and as a disinfectant. Susceptible people can be adversely affected by ozone levels as low as 40 nmol/mol. In the EU, the current target value for ozone concentrations is 120 µg/m³ which is about 60 nmol/mol. In the US the recommended EPA standard is 75 nmol/mol. At acute levels, ozone is an irritant and lachrymator. At chronically low doses (~40 nmol/mol) there is a great deal of evidence to show that ground level ozone can harm lung function and irritate the respiratory system. Long-term exposure to ozone and the pollutants that produce it is linked to premature death, asthma, bronchitis, heart attacks and other cardiopulmonary problems. Long-term exposure to ozone has been shown to increase risk of death from respiratory illness. An 18-year study on 450,000 people in the US revealed that those living in cities with high ozone levels such as Houston or Los Angeles had an over 30% increased risk of dying from lung disease. Both acute and chronic exposures to ozone can negatively impact the barrier function of the lung, and these exposures can initiate an inflammatory response from the immune system. This immune response involves the release of biologically active mediators that can have adverse effects on the lung tissue itself. Some effects may include the thickening of the air-blood barrier in the lungs, thus reducing the diffusion of oxygen into the blood. Animals exposed to ozone produce and release high amounts of a sugar known as hyaluronan. Hyaluronan has been shown to be directly responsible for causing lung airways to narrow and become irritated. (A15093) Exposure of 0.1 to 1 μmol/mol produces headaches, burning eyes and irritation to the respiratory passages. Exposure to 10 ppm ozone will cause pulmonary edema. Low doses act as a depressant and will induce sleep in certain individuals. EYES: Hold eye open and rinse slowly and gently with water for 15-20 minutes. Remove contact lenses, if present, after the first 5 minutes, then continue rinsing eye. Call a poison control center or doctor for treatment advice. INHALATION: Move person to fresh air. If person is not breathing, call 911 or an ambulance, then give artificial respiration, preferably by mouth-to-mouth if possible. Call a poison control center or doctor for further treatment advice. 2014-09-11T05:13:38Z 2026-04-16T20:47:39Z 25812 DB12510 true O1OO1 O3 InChI=1S/O3/c1-2-3-1 XQOAKYYZMDCSIA-UHFFFAOYSA-N 47.9982 47.984743866 Endogenous and Exogenous Gas HMDB35409 13375217 CHEM003683 DTXSID0021098 NS00076141 trioxirane