🎯 At a Glance
🔬 How It Actually Works
A highly toxic, carcinogenic gas. In cosmetics, it is found dissolved in water (as methylene glycol) primarily in "Brazilian Blowout" hair straightening treatments, or released slowly by certain preservatives. It is a severe respiratory and skin hazard.
💖 Why your skin loves it
Forces hair bonds to break and lay permanently flat.
⚖️ Myth vs. Fact
The Myth
"Formaldehyde-Free" keratin treatments are always safe.
The Science
Many "free" treatments simply use methylene glycol, which instantly turns back into formaldehyde when heated.