MODIFIED FCAT 167 (2) M. Hannuksela and H. Salo, The repeated open application test (ROAT), Contact Dermatitis, 14, 221-227 (1986). (3) D.D. Stube, S.W. Koontz, R. I. Murahata, and R. F. Theiler, The flex wash test: A method for evaluating the mildness of personal washing products, J. Sac. Cosmet. Chem., 40, 297-306 (1989). (4) M. F. Lukacovic, F. E. Dunlap, D. E. Michaels, M. O. Visscher, and D. D. Watson, Forearm wash test to evaluate the clinical mildness of cleansing products, J. Sac. Cosmet. Chem., 39, 355-366 (1988). (5) K.D. Ertel, B. H. Keswick, and P. B. Bryant, A forearm controlled application technique for esti- mating the relative mildness of personal cleansing products, J. Soc. Cosmet. Chem., 46, 67-76 (1995). (6) L. Phillips, M. Steinberg, H. I. Maibach, and W. A. Akers, A comparison of rabbit and human skin response to certain irritants, Toxicol. AppL Pharmacol., 21, 369-382 (1972). (7) J. Stotts, "Planning, Conduct and Interpretation: Human Predictive Sensitization Patch Tests," in Current Concepts in Cutaneous Toxicity, V. A. Drill and P. Lazar, Eds. (Academic Press, New York, 1980), pp. 41-53. (8) J. Pinnagoda, R. A. Tupker, T. Agner, and J. Serup, Guidelines for transepidermal water loss (TEWL) measurements: A report from the standardization group of the European Society of Contact Dermatitis, Contact Dermatitis, 22, 164-178 (1990). (9) S. W. Babulak, L. A. Rhein, D. D. Scala, F. A. Simion, and G. L. Grove, Quantitations of erythema in a soap chamber test using the Minolta Chroma (Reflectance) Meter: Comparisons of instrumental results with visual assessments, J. Sac. Cosmet. Chem., 37, 475-479 (1986).

j. Cosmet. Sci., 51, 169-182 (May/June 2000) Oxygen radicals from photoirradiated human hair: An ESR and fluorescence study LOUIS J. KIRSCHENBAUM, XINHUA QU, and EDWARD T. BORISH, Department of Chemistry, University of Rhode Island, Kingston, R102881. Accepted for publication March 15, 2000. Synopsis Exposure of hair to light causes degradation, the precise mechanism of which is not completely understood. Oxygen free radicals (superoxide and hydroxyl) are believed to be involved, and a variety of indirect evidence has supported this. However, to date, direct observation of oxyradicals from photoirradiated hair has been lacking. We have used complementary electron spin resonance and fluorescence techniques to assess oxyradical production when human hair is irradiated under UVA and visible light 0• -- 320 nm). ESR studies include direct observation of intrinsic melanin and keratin radicals as well as spin trapping with DMPO. The fluorescence technique is based on terephthalic acid dianion (TA) as a hydroxyl radical probe. Radical scavengers are used to compete with the probe (TA or DMPO). Our results indicate that (a) oxyradicals are produced during photoirradiation, (b) terephthalate is a convenient method to study hydroxyl production in hair, (c) radical production upon irradiation varies with hair type, and (d) the effects of radical scavengers suggest potential implications for hair care product development. INTRODUCTION Hair fibers consist primarily of fibrous proteins belonging to the keratin family. Mor- phologically, hair structure has three distinct components: the cuticle, the cortex, and the medulla. The shingle-like cuticles form the hair exterior and enclose the corticular mass. The cortex constitutes the bulk of the hair and contains tightly packed elongated cortical cells oriented parallel to the fiber axis. These cells contain alpha-helical micro- fibrils embedded in a cystine-rich amorphous protein matrix. The protein components comprising the hair fiber have differing amino acid compositions. The function of the medulla is not clear. It is composed of loosely attached spongy cells. The keratin in hair is accompanied by minor quantities of lipids. Pigmented hair contains melanin granules located within the cortex and medulla (1-3). Address correspondence to Louis J. Kirschenbaum. E-mail: Kirschenbaum@chm.uri.edu Edward T. Borish's present address is Bath and Body Works, 7 Limited Parkway East, Reynoldsburg, OH 43068. 169