People complain that TOMMIE TIPPEE sippy cups have mold in them. I don't really think it's true. My family tried so many brands of those cups. And they all seem to have the same problem. We cleaned them part by part. Mold happened to be there any way.So it doesn't look like its manufacturers fault. I think water causes all of the mold. One time I was cleaning my daughter's bottle , I saw 2 little worms there. As it turned out they came from the faucet. Imagine that. So we started to use water filter. We cleaned bottles and cups with that water only. And no more mold since tgen.