Internal combustion engine the atmosphere by the reaction of and volatile organic compounds in the presence of sunlight. Ground-level ozone is harmful to human health and the environment. Though the same chemical substance, ground-level ozone should not be confused with stratospheric ozone, or the ozone layer, which protects the earth from harmful ultraviolet rays. Carbon fuels contain sulfur and impurities that eventually produce sulfur monoxides (SO) and sulfur dioxide (SO) in the exhaust, which promotes acid rain. In the United States, nitrogen oxides, PM, carbon monoxide, sulphur dioxide, and ozone, are regulated as criteria air pollutants under the Clean Air Act to levels
Lower sulfur oxides Jupiter's moons, and Venus contain significant amounts of sulfur oxides. Some compounds reported by early workers such as the blue "sesquioxide", SO, formed by dissolving sulfur in liquid SO appears to be a mixture of polysulfate salts of the S and S ions. These species are all very unstable and are observed as fleeting intermediates in the gas phase. At a few millibars pressure, the relative stabilities are SO > SO > SO. Sulfur monoxide (SO) and its dimer (SO) have been trapped at low temperature. Disulfur dioxide (SO) is a dimer of sulfur monoxide. It has C structure (planar).