Indoor environment factor · measured in µg/m³
Nitric oxide (NO)
Part of: Nitrogen oxides (NOₓ)
Also: NO, nitrogen monoxide, nitric oxide
A colourless gas produced by any high-temperature flame and by the body itself. Indoors it is the first product of combustion in air, and it converts to nitrogen dioxide over minutes — so the two are measured together and interpreted together.
What it is
A flame makes nitric oxide, not nitrogen dioxide: the heat forces nitrogen and oxygen from the air to combine, and what leaves the burner is overwhelmingly the monoxide. Oxidation to the dioxide follows in the room over minutes, faster where ozone is present.
Two consequences follow for interpretation. Close to a burner the ratio between the two gases is high, and further away in time and space it falls — so measuring both tells how fresh the combustion is, which a single measurement of either cannot. And nitric oxide consumes ozone as it oxidises, which is why a kitchen with a gas hob running has less ozone than the rest of the dwelling.
The same molecule has a separate life as a signalling substance made by the body, which is what exhaled nitric oxide measures — the same compound, a different question entirely.
What the studies report
| Linked to | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Gestational diabetes | OR 1.04 (1.03–1.06) | pregnant women | systematic review and meta-analysis of 35 epidemiological studies (33 cohort, 1 cross-sectional, 1 case-control) covering 6,939,725 pregnant women | F-0081 Association of air pollution and fine particulate matter (PM… (2023) | machine |
Each row is one Finding — a sentence as printed in one study, recorded with its page in the Coridum Knowledge Base. Follow the Finding number for the exact wording and the citation. Checked says who verified the row: machine means every automatic check passed and the surrounding text was read; person means someone read the sentence in the document. Rows are re-checked by a person over time. The studies are curated in the Coridum Knowledge Base; the reading of them together is a Claim, shown separately.
Identifiers
Cite this page
Coridum Research. Nitric oxide (NO). Coridum Knowledge G-0188, 16 September 2026. https://coridum.com/k/G-0188/