There are so many beauty terms that it can make your head spin. Confused as to what it all means? Our Glam Glossary will help you sort it all out. Follow Allison each week in her quest to decode popular beauty terms, from Alpha Hydroxy Acids to Zinc Oxide.

Parabens

What they are: Parabens are the class of chemicals – including methlyparaben, ethylparaben, propylparaben and butylparaben – most widely used in cosmetics as preservatives, according to the FDA.

Where you see them: Shampoo, moisturizer, toothpaste, shaving gel, moisturizer, makeup.

What they do: As preservatives in cosmetics, parabens are used to inhibit the growth of bacteria and fungi in products.

Paraben-free products are very common now

Are they safe? There isn’t enough research to say that they aren’t safe. In 2004, a small study stirred the pot of public worry when it found traces of parabens in a major percentage of breast cancer tumors, thereby insinuating that parabens (in this case, parabens found in antiperspirants were, for some reason, targeted) were the cause of the disease. A slew of unofficial, unprofessional and unfounded emails circulated the internet and took the study out of context: The study didn’t actually show that parabens caused or contributed to breast cancer, only that they were present. It also didn’t determine where the parabens had come from.

In response, the Cosmetic Ingredient Review reassessed its safety review of parabens in 2005 only to determine that there was no need to reverse its original conclusion, reaffirming that parabens are safe in cosmetics. Even the American Cancer Society agrees that “larger studies are needed to find out what effect, if any, parabens might have on breast cancer risk.” Still, many manufacturers have turned away from the chemical in the wake of the public’s discomfort. The absence of parabens in any product sold on Sephora’s website will be prominently displayed in the “What it is formulated WITHOUT” section of the product’s description.

Photo Collage: Tarte, Sephora, Carol’s Daughter