What's in it? Pullulan
What's it used in? An edible and mostly tasteless polymer produced from starch, pullulan is found in breath fresheners and oral hygiene products such as mouthwash, tooth whiteners and lipstick.
What does it do? It's used to bind ingredients together.
Any controversy? A 1985 study showed concerns of cancer, within vitro tests of non-mammalian cells showing mutation.