sulfur dioxide

American  

noun

Chemistry.

1. a colorless, nonflammable, water-soluble, suffocating gas, SO 2 , formed when sulfur burns: used chiefly in the manufacture of chemicals such as sulfuric acid, in preserving fruits and vegetables, and in bleaching, disinfecting, and fumigating.

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sulfur dioxide Scientific  

1. A colorless, poisonous gas or liquid with a strong odor. It is formed naturally by volcanic activity, and is a waste gas produced by burning coal and oil and by many industrial processes, such as smelting. It is also a hazardous air pollutant and a major contributor to acid rain. Chemical formula: SO ₂ .

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Etymology

Origin of sulfur dioxide

First recorded in 1865–70

Example Sentences

See Examples For:

sulfur dioxide

The agency also refused to assign any benefits to the reduction of pollutants like nitrogen oxides and sulfur dioxide.

From Slate ● Aug. 2, 2026

When an incoming ion strikes an oxygen-treated surface, two oxygen atoms can combine with a nearby sulfur atom to form sulfur dioxide, a stable gas that can naturally leave the surface.

From Science Daily ● Jun. 17, 2026

At one coal-burning unit, emissions for mercury, nitrogen oxide and sulfur dioxide were well under permitted levels, according to hourly and 24-hour measurements on a computer screen.

From The Wall Street Journal ● May 21, 2026

It’s one of the nation’s largest sources of sulfur dioxide, which forms haze and harms the respiratory system, and the second-largest source of carbon dioxide, according to EPA data.

From Salon ● May 10, 2026

The very thin and tenuous atmosphere of Io was found by Voyager to be composed mainly of sulfur dioxide.

From "Cosmos" by Carl Sagan