Putting a Carcinogen on Your Hair - Diethanolamine in Shampoo

Journal of AOAC INTERNATIONAL Volume: 88 Issue: 2 Page(s): 592-594 March 2005

Determination of Diethanolamine in Shampoo Products Containing Fatty Acid Diethanolamides by Liquid Chromatography with a Thermal Energy Analyzer
Author(s): Hardy J. Chou 1


A liquid chromatography (LC) method using a thermal energy analyzer (TEA) is described for the determination of diethanolamine (DEA) in shampoo products containing fatty acid diethanolamides. DEA was converted to N-nitrosodiethanolamine (NDELA) by dissolving a portion of the product in 6M acetic acid and mixing with sodium nitrite for 1 h at room temperature. The reaction mixture was dried, dissolved in acetone, and analyzed for NDELA by LC-TEA. The recovery of DEA from 2 shampoo products at fortification levels of 25, 250, and 1000 ppm ranged from 70 to 105%. Twenty shampoo products were analyzed by this method, and 19 were found to contain DEA at levels ranging from 140 to 15 200 ppm.
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BrooklynDodger(s) comment: NTP bioassays of diethanolamine and diethanolamine fatty acid condensates by skin exposure provided clear evidence of carcinogenicity in male and female mice, but not the rat. Some years ago, IARC relegated DEA to group 3, not classifiable. The working group considered the male and female mouse experiments to be a single study - not so under current rules - and declined to consider the fatty acid condensate studies to be DEA studies. Years later, DEA exposure to much of the population continues.