Manufacturers of flux usually point out that inhaling flux fumes, created when flux is heated to soldering temperatures, will cause irritation to nose, throat and respiratory organs. Health authorities also state that extended or repeated exposure to rosin flux may cause hypersensitivity and lead to occupational asthma.
Not good, right?
Perhaps, what you need to avoid inhaling those nasty fumes is a fume extractor.
Come to think of it, element14 is roadtesting a fume extractor right now. You might want to walk on over and sign up for this roadtest and get a FREE chance to get one at NO CHARGE.