Sulfates is a cleansing agent that removes oil and dirt. Some studies show the ingredient can irritate eyes and skin.
It's a salt that forms when sulfuric acid reacts with another chemical. It's a broader term for other synthetic sulfate-based chemicals, such as sodium lauryl sulfate (SLS) and sodium laureth sulfate (common ingredient in shampoo).
According to Allure's Jenna Rosenstein, more than hundred of varieties exist—while some synthetic (derived from sulfur- and petroleum-based products), others obtained from natural sources.