When I turn the a/c blower on, I smell an unusual odor coming from the a/c vent. 99 328i e46. Any idea of the cause?

my heater used to blow a green mist into the cabin whenever I switched it on, with an atifreeze odor. I hope you're not breathing refrigerant or something, you could die.

pull the vent covers off and spray lysol in there, it most likely mildew from condensation.