CHICAGO—A study conducted by ChemRisk LLC found professional hair smoothing treatments—even those labeled formaldehyde-free—have the potential to produce formaldehyde concentrations that meet or exceed current occupational exposure limits (J Occupat Environ Hygiene. 2011;8(11):686-99). The exposure simulation study was conducted to characterize potential formaldehyde exposures of salon workers and clients during keratin hair smoothing treatments. Four different hair treatment brands (Brazilian Blowout, Coppola, Global Keratin, and La Brasiliana) were applied to separate human hair wigs mounted on mannequin heads. Short-term (six to 16 minutes) and long-term (41 to 371 minutes) personal and area samples (at distances of 0.5 to 3.0 m from the source) were collected during each treatment for the one-day simulation. A total of 88 personal, area and clearance samples were collected. Results were analyzed based on task sampling (blow-dry, flat-iron), treatment sampling (per hair product) and time-weighted averages (per hair treatment, four consecutive treatments). Real-time monitoring of tracer gas levels, for determining the air exchange rate, and formaldehyde levels were logged throughout the simulation. Bulk samples of each hair treatment were collected to identify and quantify formaldehyde and other chemical components that may degrade to formaldehyde under excessive heat.
Mean airborne concentrations of formaldehyde ranged from 0.08 to 3.47 ppm during blow-dry and 0.08 to 1.05 ppm during flat-iron. During each treatment, the mean airborne concentrations ranged from 0.02 to 1.19 ppm throughout different zones of the salon. Estimated eight-hour time-weighted averages for one treatment per day ranged from 0.02 ppm for La Brasiliana to 0.08 to 0.16 ppm for Brazilian Blowout. For four treatments per day, means ranged from 0.04 to 0.05 ppm for La Brasiliana to 0.44 to 0.75 ppm for Brazilian Blowout. Using all four products in one day resulted in estimated eight-hour time-weighted averages ranging from 0.17 to 0.29 ppm. Results from bulk sampling reported formaldehyde concentrations of 11.5 percent in Brazilian Blowout, 8.3 percent in Global Keratin, 3 percent in Coppola, and 0 percent in La Brasiliana. Other products that degrade into formaldehyde were detected in Global Keratin, Coppola and La Brasiliana.