org/wiki/Volatile_organic_compounds
There are synthetic VOCs as well, which are commonly used in
paint and some cleaners.
Paint is a real biggie. I have asthma
and migraines, and paint can set off an attack of either. There is a low or no VOC paint available now, in several brands. There is still some smell, but the smell is much less, lingers a lot less, and doesn't usually set off asthma/migraines if you have the room ventilated. I also read VOC is also in some dry cleaning solvents.