436 JOURNAL OF COSMETIC SCIENCE ACKNOWLEDGMENTS This study was carried out in connection with the TRI project "Analysis and Quanti- fication of Hair Damage," supported by a group of TRI corporate participants. We thank Ms. Sigrid B. Ruetsch for the optical microscopy analyses and Mr. Xin-Xian Huang for supplying us with single-component dyed hair. REFERENCES (1) R.F. Stature, M. L. Garcia, and J.J. Fuchs, The optical properties of human hair. I. Fundamental considerations and goniophotometer curves, J. Soc. Cosmet. Chem,, 28, 571-599 (1977). (2) W. Czepluch, G. Hohm, and K. Tolkiehn, Gloss of hair surfaces: Problems of visual evaluation and possibilities for goniophotometric measurements of treated strands,J. Soc. Cosmet. Chem., 44, 299-317 (1993). (3) H. K. Bustard and R. W. Smith, Investigation into the scattering of light by human hair, Applied Optics, 30, 3485-3491 (1991). (4) A. Guiolet, J. C. Gatson, and J. L. Levecque, Study of the optical properties of human hair, Int. J. Cosmet. Sci., 9, 111-124 (1987). (5) C. Reich and C. R. Robbins, Light scattering and shine measurements of human hair: A sensitive probe of the hair surface, J. Soc. Cosmet. Chem., 44, 221-234 (1993). (6) J. H. S. Rennie, S. E. Bedford, andJ. D. Hague, A model for the shine of hair arrays, Int. J, Cosmet. Sci., 19, 131-140 (1997). (7) C. Scanavez, M. Zoega, A. Barbosa, and I. Joekes, Measurement of hair luster by diffuse reflectance spectrophotometry, J. Cosmet. Sci., 51, 289-302 (2000). (8) Y. Tango and K. Shimmoto, Development of a device to measure human hair luster,J. Cosmet. Sci., 52, 237-250 (2001). (9) S. Nagase, S. Shibuichi, K. Ando, E. Kariya, and N. Satoh, Influence of internal structures of hair fiber on hair appearance. I. Light scattering from the porous structure of the medulla of human hair, J. Cosmet. Sci., 53, 89-100 (2002). (10) M. Okamoto, R. Yakawa, A. Mamada, S. Inoue, S. Nagase, S. Shibuichi, E. Kariya, and N. Satoh, Influence of internal structures of hair fiber on hair appearance. III. Generation of light-scattering factors in hair cuticles and the influence on hair shine, J. Cosmet. Sci., 54, 353-366 (2003). (11) F.J. Wortmann, E. Schulze zur Wiesche, and A. Bierbaum, Analyzing the laser-light reflection from human hair fibers. I. Light components underlying the goniophotometric curves and fiber cuticle angles,J. Cosmet. Sci., 54, 301-316 (2003). (12) R. McMullen and J. Jachowicz, Optical properties of hair: Effect of treatments on luster as quantified by image analysis, J. Cosmet. Sci., 54, 335-351 (2003). (13) K. Keis, K. R. Ramaprasad, and Y. K. Kamath, Studies of light scattering from ethnic hair fibers, J. Cosmet. Sci., 55, 49-63 (2004). (14) K. C. Brown, in Hair and Hair Care, D. H. Johnson, Ed. (Marcel Dekker, New York, 1997), p. 195. (15) S.K. Han, Y. K. Kamath, and H.-D. Weigmann, Diffusion of semipermanent dyestuffs in human hair, J. Soc. Cosmet. Sci., 36, 1-16 (1985).

j. Cosmet. Sci., 55, 437447 (September/October 2004) Hair color changes caused by dyeing and thermal treatments ANA CAROLINA SANTOS NOGUEIRA, CARLA SCANAVEZ, CRISTIANE CARNELOS, ALEXANDRE GASPARI, and INI•S JOEKES, Instituto de Qu/mica, Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6154, 13084-971 Campinas, SP, Brazil. Accepted for publication August 26, 2004. Presented at the 22 " IFSCC Congress, Edinburgh, Scotland, September 2002. Synopsis The aim of this study was to show the effect of heat exposure, dyeing, and shampooing on hair color as measured by diffuse reflectance spectrophotometry. Successive dyeing of virgin hair with six permanent commercial formulations showed that color saturation was obtained after the first dyeing cycle. An unex- pectedly high difference in hair color saturation, measured as DE* values, was obtained for virgin hair samples that differed only in cleansing history. After six sequential washings of the dyed hair samples, no difference was observed in color durability, indicating that the adhesion strength is similar to long-lasting and tone-up dyeing formulations. Exposure to a hot plate at 172øC showed a significant darkening of the virgin hair samples after 2 min. On the other hand, virgin hair samples exposed to the gentler heat of a hand dryer (-60øC) showed partial disappearance of the hair medulla after 60 min. However, values of total color difference were near the error limit. INTRODUCTION Hair health is frequently related to its color and gloss. Hair color is attributed to the melanin granules present in the cortex (1). However, only a few papers are found in the literature involving hair color. This paper describes the color properties of hair as related to some simple cosmetic treatments. McMullen and Jachowicz (2) studied the effect of curling irons on hair color. Samples were submitted to a hot plate at 160øC for 30 min. Color analysis was done using the Hunter L*, a*, b* color coordinates. Significant color changes were observed, such as an increase in yellowness of white and Piedmont hair and yellowing and darkening of bleached hair. The most frequent gloss measurement is the specular gloss, which corresponds to the Address all correspondence to In•s Joekes. 437