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

In 2024, the company commissioned studies that found what it described as regular levels of sulfur dioxide, which is produced during the processing of copper-cobalt ore.

From The Wall Street Journal • Mar. 9, 2026

Brief peaks of exposure to irritants such as sulfur dioxide can damage airways and even be fatal, especially for children, Nemery said.

From The Wall Street Journal • Mar. 9, 2026

And although landfill operators routinely monitor for potentially dangerous gases, such as methane or sulfur dioxide, they typically don’t have instruments that would detect toxic contaminants in wildfire ash, like lead or asbestos.

From Los Angeles Times • Feb. 7, 2025

The company has focused its efforts on developing balloons releasing stratospheric aerosols, mainly sulfur dioxide.

From Salon • Dec. 12, 2024

“You’ve smelled rotten eggs? That’s sulfur dioxide, released from the chemical reaction of rotting organic material. This is going to stink just like that.”

From "October Sky" by Homer Hickam