Yes, I know this is a topic bump, sorry (I’ve just run into a couple of these devices being used in the wild by people who believed they were doing the right thing)
The reason I consider these dangerous is that they only have an alcohol (VOC) sensor onboard
eCO and eCO2 are derived values supposedly based on human respiration - but they’re not. Somewhere along the line some marketer read half a paragraph and jumped to conclusions
I made a deeper posting about the issue a while back at Air Quality sensors - CO2/CO - dangerous fakery
I can’t stress enough that there need to be 8 foot high warnings everywhere in the home automation community against using these devices
In the best case scenario, the readings are utterly ficticious. In the worst case scenario someone will end up dead