Salon Air Quality & Ventilation Code Experts


When heated, methylene glycol creates formaldehyde vapors.  Hair stylists and salon owners are starting to understand this fact.

The days of “formaldehyde free” claims being placed on product labels which contain formaldehyde releasers and neglecting the necessity for proper ventilation are over.  For example, every bottle of Brazilian Blowout now has a bright sticker affixed to it clearly stating that the treatment needs to be performed in a well ventilated area and to be used as directed.

The caution on the bottle now reads:

“This product contains methylene glycol.  When heated this product releases formaldehyde.  Use in a well-ventilated area and only as directed.”

Formaldehyde vapors are released when high heat is applied during blow drying, product application, and flat ironing.  The best way to prevent clients’ and stylists’ overexposure to formaldehyde vapors is to use local source capture ventilation, as stated by the Professional Keratin Smoothing Council’s  Oct. 2011 press release:

Aerovex Systems, one of our founding members, is the developer of a hair salon source capture ventilation system, which provides a premiere example of “appropriate” salon ventilation equipment.  Such equipment is useful for many types of salon services, including keratin hair smoothing, and can offer an extra layer of protection to help ensure the safety of clients and cosmetologists.”

All of the names listed below are listed under OSHA’s formaldehyde standard or can release formaldehyde when subjected to certain conditions (such as the high heat involved in a hair smoothing treatments).  OSHA has provided a list of what it calls “synonyms” for formaldehyde:

Methylene glycol


Methylene oxide


Formic aldehyde




Timonacic acid

Thiazolidinecarboxylic acid