Its possible
Actually got what could have been a mild case last year from (undisclosed_location) while (task) shortly after which they improved ventilation. Symptoms were flu-like at first but for a good 2 weeks I felt like death warmed up and was convinced it was mild CO poisoning as it resolved when not at (undisclosed_location) yet despite other people complaining nothing was done.
Formaldehyde is used to preserve cadavers so needless to say it is *NOT* good for the living at all.
I did wonder if ammonia could also have been the culprit as this killed a fair few people back when it was used in refigeration until replaced by CFC then HFC.
Another often ignored danger is inert gases, which in combination with CO can be many times deadlier than either on their own, even a relatively small argon leak (say bad regulator) can exclude enough oxygen to cause dizziness and possible collapse.
There is an argument to make CO/O2 combination meters mandatory for all laser cutters and welders, both can be deadly if misused.
Biting the hand that feeds IT
