Glyoxal.

The Expert Panel for Cosmetic Ingredient Safety reviewed information that has become available since their year 2000 assessment, along with updated information regarding product types, and frequency and concentrations of use, and reaffirmed their original conclusion that Glyoxal is safe for use in products intended to be applied to the nail at concentrations ≤1.25% and that the available data are insufficient to support the safety for other uses.
Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.