We bought a large package of dry rice vermicelli recently at our local Thai market. We've cooked it a couple of times, and both times once it starts to boil it gives off a chemical odor, sort of like lye or chlorine (not really either, but that kind of thing). It doesn't rinse off, though rinsing helps a bit. Once rinsed, the chemical smell is not strong enough that it's a problem if you have any kind of sauce on the noodles, but eaten plain they definitely have a chemical funk.
I haven't cooked with this style of rice noodle a lot (we usually do cellophane noodles, which seem different), so maybe this is normal. Can anybody tell me if this is something we should expect with this kind of noodle?
The package was new, clean, and in perfect condition, so if there was some kind of contamination it happened in the factory.