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.

4 Answers 4


I've made rice vermicelli many times, and I've never smelled anything like what you describe. I suggest throwing out the ones you have, and buying a different brand (or maybe shopping at a different store).


I would not eat those noodles. It sounds to me as if something like a cleaning compound was spilled on them in transit. If contact was prolonged, chemicals could pass through the packaging without it being unsealed, and a wipe with a cloth would make the package "look right".


I had the same experience, with the smell as described. I found this article about oxalic acid and tinopal being found in rice noodles, but it doesn't say whether it results in a smell. I don't have an ultraviolet lamp at home to check if that was the issue (as mentioned in the article).

  • 3
    Hi and welcome! That sounds interesting but maybe you could include a bit of a summary in your answer? Answers that rely on a link-only are discouraged because they aren't useful in the future if the link changes / dies.
    – PeterJ
    Commented Mar 8, 2015 at 12:14
  • Oxalic acid (which is harmless up to a certain dose, it is in a lot of leafy greens, those very rich in it are usually supposed to be cooked) and Tinopal (laundry brightener ,has no business in food) found in rice noodles. Commented Dec 6, 2015 at 4:24
  • I've edited your answer to make it more clear that you actually don't know whether the article applies here - you and the OP noticed the smell, the article mentions oxalic acid and tinopal, but there's no connection.
    – Cascabel
    Commented Dec 6, 2015 at 21:26

We just bought vermicelli noodles and after boiling them there was an intense chemical odour. At first thought it might just be the mung beans because we'd never had those before haha. Then after seeing people comments about potential chemicals seaping into them or being used to bleach them, as described in this article http://vnnewscenter.blogspot.com/2013/06/how-to-tell-noodles-contain-toxic.html , we thought it better not to risk it, and threw them all in the bin.

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