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METHYLENE GLYCOL

Description

Methylene glycol, also known as formaldehyde in water solution, is a controversial ingredient in hair smoothing treatments. This compound is formed when formaldehyde gas dissolves in water, creating a equilibrium mixture. In haircare products, methylene glycol acts as a preservative and a key component in some keratin straightening treatments.

When heat is applied during the hair smoothing process, methylene glycol releases formaldehyde gas, which temporarily alters the hair's protein structure, resulting in straighter, smoother hair. However, this release of formaldehyde has raised significant safety concerns. Exposure to formaldehyde can cause irritation to the eyes, nose, and throat, and it is classified as a known human carcinogen by the International Agency for Research on Cancer.

Due to these health risks, many countries have restricted or banned the use of methylene glycol in hair smoothing products. Regulatory bodies, including the FDA, have issued warnings about its use in cosmetics. Alternative formulations using glyoxylic acid or other compounds have been developed to provide similar smoothing effects without the associated health risks of methylene glycol.