nitrogen dioxide

American  

noun

Chemistry.

1. a reddish-brown, highly poisonous gas, NO 2 , used as an intermediate in the manufacture of nitric and sulfuric acids, and as a nitrating and oxidizing agent; a major air pollutant from the exhaust of internal combustion engines that are not fitted with pollution control devices.

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nitrogen dioxide British  

noun

1. a red-brown poisonous irritating gas that, at ordinary temperatures, exists in equilibrium with dinitrogen tetroxide. It is an intermediate in the manufacture of nitric acid, a nitrating agent, and also an oxidizer for rocket fuels. Formula: NO 2

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Example Sentences

According to one study, nitrogen dioxide -- a gas emitted by cars -- dropped by 40 percent between 2012 and 2022 in the Paris region.

From Barron's • Mar. 15, 2026

A 2024 investigation by the same research team found that gas stoves release nitrogen dioxide at unsafe levels that persist for hours after cooking ends.

From Science Daily • Dec. 3, 2025

Meanwhile, total exposure is highest in major cities, where outdoor nitrogen dioxide levels are already elevated and smaller living spaces allow stove emissions to accumulate more easily.

From Science Daily • Dec. 3, 2025

Satellite measurements showed a distinct rise in nitrogen dioxide, or NO2, across the southeastern Atlantic Ocean.

From Science Daily • Nov. 26, 2025

The nitrogen dioxide formed in this reaction can now enter into combination with a new quantity of sulphur dioxide, steam, and oxygen, and the series of reactions go on indefinitely.

From An Elementary Study of Chemistry by McPherson, William