Finding F-1236

“This 2.6 ppbv (3.2 μg m−3) increase in formaldehyde concentration when the tree was placed in the chamber is the maximum concentration increase due to initial primary emissions for this tree (the researcher setting up the tree in the stand could have contributed to this value).”

Poppendieck et al. Jingle bells, what are those smells? Indoor VOC emissions from a live Christmas tree (2024). Indoor environments. Page 9. 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 2.6
Caveat: the study notes that the researcher setting the tree in its stand could have contributed to the increase

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.