COMPARISON OF MONOETHANOLAMINE AND AMMONIA HAIR COLORANTS 9 well known. However, more concerning is that if MEA is substituted for ammonia, using cysteic acid level as a measure of damage can be somewhat misleading. However, SEM showing cuticle removal and protein loss, clearly show damage increases for unbuffered equimolar solutions of MEA chassis versus ammonia chassis. Further investigation of other in-use variables and chassis is warranted, as is determination of the specifi c protein fragments that are lost from the hair. For the time being, though, if the ammonia odor of Level 3 products is a concern, a better approach may be to minimize its volatility rather than replacing it with a potentially more damaging alkalizer. ACKNOWLEDGMENTS The authors thank Mr. Firoj Vohra for his helpful discussions of MEA-based product performance and history, Sheila Childers for her assistance with SEM, Mr. Mike Davis and Ms. Abby Newland for their assistance with measurement of protein damage, and Dr. John Gardlik for his helpful discussions of the manuscript. REFERENCES (1) W. A. Poucher, Revised by G. M. Howard, Hair Colorants, in Perfumes, Cosmetics and Soaps, 8th Ed., Vol. 3. Modern Cosmetics (Chapman and Hall, London, 1974), pp. 164–195. (2) B. P. Murphy, Hair Colorants, in Poucher’s Perfumes, Cosmetics and Soaps, 10th Ed., H. Butler. Ed. (Kluwer Academic Publishers, London, 2000), pp. 307–324. (3) J.-A. Seo, I.-H. Bae, W.-H. Jang, J.-H. Kim, S.-Y. Bak, S.-H. Han, Y.-H. Park, and K.-M. Lim, Hydro- gen peroxide and monoethanolamine are the key causative ingredients for hair dye-induced dermatitis and hair loss, J Dermatol Sci., 66 (1), 12–19 (2012). (4) J. M. Marsh and C. J. Clarke, Hair coloring compositions, U.S. Patent 7,204,861 B2 (2007). (5) H. D. Boswell, J. M. Marsh, J. S. Park, and M. A. Olshavsky, Oxidative treatment of hair with reduced hair damage, U.S. Patent 7,179,302 B2 (2007). (6) M. S. Bil and W. H. Brunner, Dyeing process and composition, G.B. Patent 1,136,659 (1966). (7) B. P. Murphy, K. C. Brown, T. M. Schultz, and A. A. Mayer, Dye compositions containing 5,6-dihy- droxyindoles and a foam generator, U.S. Patent 5492541 (1996). (8) Modifi ed Lowry Protein Assay kit supplied by Thermo Scientifi c, Pierce Protein Biology Products, Rockford, IL. http://www.piercenet.com/browse.cfm?fl dID=02020103, November 2011 (9) K. R. Naqvi, J. M. Marsh, S. Godfrey, M. G. Davis, M. J. Flagler, J. Hao, and V. Chechik, The role of chelants in controlling Cu(II)-induced radical chemistry in oxidative hair coloring products, Int J Cosmet Sci., 35, 41–49 (2013).