Have you ever experienced a rash or skin irritation after using synthetic hair for braids? Was your scalp itchy to the point where you had to wash your hair or take out your style? Researchers might have unlocked the answer as to why this reaction could be happening.

Braided hairstyles offer convenience for mostly African American girls and women who add human hair or synthetic fiber extensions to their hair. Consumer Reports (CR) has formally called into question the safety of braiding hair.

Celebrity stylist Kim Kimble previously told Bazaar that, ultimately, the best braiding hair to use is one that seamlessly matches your unique texture. “The hair you select is all based on the style you want, but you always want to make sure you’re reaching for quality hair,” she said.

When the hair is dipped in hot water during installation—a standard practice—it releases volatile organic compounds, or VOCs, that can irritate eyes, throat, and lungs.