We’ll admit it. Most of us have been soldering since we were kids and we don’t think of it as a particularly dangerous activity. Just keep the hot and cold end of the iron straight and remember not to flick solder off the tip on your leg and you are fine. We sometimes roll our eyes a bit at the people with the soldering fume extractors unless you are soldering 8 hours a day, although we’ve occasionally used a small fan nearby just to get some circulation. [Tanner Tech’s] video on soldering fumes might make us rethink that, though (see below).
[Tanner] rigs up a fan with some plastic bottles, fans, and some cotton balls. But that didn’t do very much. Instead, he replaced his fan assembly with a shop vac. Then he examined what was on the cotton balls.
Realistically, the cotton balls probably got nearly all the fumes from the things he soldered. In real life, your lungs would get only a small percentage of that. Still, the cotton balls and even the housing were full of flux residue and fumes. The cotton was very sticky and coated with a yellow substance. and a white powder.
You can imagine your lungs getting even a little of the gunk that was on the cotton balls. It would be interesting to do some analysis to determine what all that residue was.