Cosmetic chemist Stephen Alain Ko has his concerns about the term. "Unfortunately, many lists that determine whether an ingredient is considered 'clean' or not are based on incomplete data," Ko said. "There is also little consistency among labels, so some ingredients considered 'clean' by one retailer are not considered 'clean' by another, which can lead to confusion for consumers."
He also dislikes what the trend has done for preservatives, which are essential to keeping your products from going bad. Because so many preservatives have been deemed "unsafe" by the clean movement (for example, parabens, formaldehyde releasers, and triclosan), there are fewer options for formulators to work with. "New alternatives aren't being developed as quickly," Ko said. "Many times, the newer, 'cleaner' preservatives have less safety data than the ones they are meant to replace."
The other downside to using fewer preservatives: "This has led to an increase in bacterial and fungal contamination in some commercial 'clean beauty' products," Ko said.