Methanediol

Methanediol, also known as formaldehyde monohydrate or methylene glycol, is an organic compound with chemical formula CH2(OH)2. It is the simplest geminal diol, and formally the second simplest carbohydrate (after formaldehyde).Methanediol, rather than formaldehyde, is listed as one of the main ingredients of 'Brazilian blowout', a hair-straightening formula marketed in the US. The equilibrium with formaldehyde has caused concern since formaldehyde in hair straighteners is a health hazard, but the risk has been disputed.