What's in it? Cellulose gum
Other names it goes by Acetic acid, cellulose ether, carboxymethyl cellulose, sodium salt.
What's it used in? Toothpaste, foundation, moisturiser, mascara and masks.
What does it do? It's used to bind and stabilise ingredients.
Any controversy? The American Association for Cancer Research found in 1997 that high doses can lead to tumours, while the Food and Chemical Toxicology journal found in 1995 that high doses produce metabolic affects. The gum's added to cheese and other foods, and the FDA is checking toxicity.