Indoor environment factor · measured in µg/m³
Monoterpenes
Part of: Terpenes
Also: monoterpene, monoterpenoids, alpha-pinene, pinene, delta-3-carene
Terpenes built from two isoprene units, with ten carbon atoms — limonene, alpha-pinene, delta-3-carene and their relatives. They are the volatile fraction of conifer wood and of citrus and pine fragrances, and the subgroup indoor surveys most often report as a sum.
What it is
Where terpenes is the family, monoterpenes is the part of it that indoor air actually contains in quantity. Ten carbon atoms give a volatility that keeps them in the gas phase at room temperature, so they are captured on a standard sorbent tube and reported individually or summed.
Their distribution follows two sources that a single figure cannot separate. Softwood and products made from it release alpha-pinene and delta-3-carene continuously, strongest in new construction and falling as the material ages; fragranced products release limonene in pulses tied to cleaning and to air fresheners. A high monoterpene concentration in a newly built wooden house and in a heavily cleaned flat mean different things.
What they share is reactivity with ozone, and pinene is as ready a partner in that chemistry as limonene, producing aldehydes and new particles in the room.
What the studies report
| Linked to | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Cleaning products | a stated direction without a concentration; one room cleaned with one commercial product | — · office | experiment in a mechanically ventilated office room: the floor was cleaned with a commercial terpene-based disinfectant while gas-phase precursors, oxidants, radicals, secondary oxidation products and aerosols were measured in real time | F-1304 Chemistry and human exposure implications of secondary organ… (2022) | machine |
| Emission test chamber method | emission-rate 12.4 | — · test chamber | chamber study at the National Institute of Standards and Technology: a freshly cut Douglas fir stood for seventeen days in an environmentally controlled chamber and the volatile organic compounds it emitted were measured continuously with a proton transfer reaction mass spectrometer, with ozone injected on several of the days to observe the indoor chemistry it starts | F-1232 Poppendieck et al. Jingle bells, what are those smells? Indoor VOC emissions fr… (2024) | machine |
| Emission test chamber method | emission-rate 1 | — · test chamber | chamber study at the National Institute of Standards and Technology: a freshly cut Douglas fir stood for seventeen days in an environmentally controlled chamber and the volatile organic compounds it emitted were measured continuously with a proton transfer reaction mass spectrometer, with ozone injected on several of the days to observe the indoor chemistry it starts | F-1233 Poppendieck et al. Jingle bells, what are those smells? Indoor VOC emissions fr… (2024) | machine |
| Emission test chamber method | — | — · test chamber | chamber study at the National Institute of Standards and Technology: a freshly cut Douglas fir stood for seventeen days in an environmentally controlled chamber and the volatile organic compounds it emitted were measured continuously with a proton transfer reaction mass spectrometer, with ozone injected on several of the days to observe the indoor chemistry it starts | F-1238 Poppendieck et al. Jingle bells, what are those smells? Indoor VOC emissions fr… (2024) | machine |
| Emission test chamber method | difference 4.2 | — · test chamber | chamber study at the National Institute of Standards and Technology: a freshly cut Douglas fir stood for seventeen days in an environmentally controlled chamber and the volatile organic compounds it emitted were measured continuously with a proton transfer reaction mass spectrometer, with ozone injected on several of the days to observe the indoor chemistry it starts | F-1240 Poppendieck et al. Jingle bells, what are those smells? Indoor VOC emissions fr… (2024) | 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
- MeSH
- D039821
Cite this page
Coridum Research. Monoterpenes. Coridum Knowledge G-0155, 16 September 2026. https://coridum.com/k/G-0155/