Finding F-1234

“The increase in formaldehyde concentration was between 1 ppbv (1.2 μg m−3) and 1.5 ppbv (1.9 μg m−3) for days with ozone injections.”

Poppendieck et al. Jingle bells, what are those smells? Indoor VOC emissions from a live Christmas tree (2024). Indoor environments. Page 8. CKB 6007

Structure

Factor: Formaldehyde (CH₂O)
Method: Emission test chamber method
Setting: test chamber, US
Study design: 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 (class 4)
Effect: difference 1.5
Caveat: the upper end of the printed range is recorded as the estimate and the whole range sits in its own field

A Finding records what one published document states, verbatim and with its page. It is not a conclusion of Coridum; see the Claims that build on it.