EVALUATION OF HAIR DAMAGE 349 hair. Rinsing for 25 minutes in running deionized water was followed by 10 minutes in 3% H202 at pH 7. After a ten-minute rinse under running water, the tresses were removed from the rods and rinsed for two more minutes, followed by blow drying. This cycle was repeated to produce tresses with one, two, and three perm treatments. Grooming simulation treatments. We have simulated grooming processes by sub- jecting the hair to a number of cycles of combing, shampooing, shampooing plus combing, and shampooing plus conditioner treatment plus combing. Untreated hair and samples with two levels of oxidative damage were selected for evaluation. Each hair bundle was 13 cm long and contained about 1375 hairs. Four grooming sequences were applied, as outlined in Table I. Each grooming sequence was performed on wet hair, and was repeated for ten cycles, each time after drying several hours under ambient conditions. Combing was done by hand, with 25 strokes through each of the four sides of the hair bundle. The total time of combing was 1.25 minutes per 100 strokes. The standard "Ace" comb of brown nylon had 65 tines in 11 cm length. Wet hair was blotted between paper towels prior to combing. Shampoo was applied to the wet hair swatch with a 1 ½m 3 syringe and was massaged into the hair by hand for two minutes. The hair swatch was then rinsed for two minutes under running deionized (DI) water. Conditioner (1 ½m 3) was applied to wet hair and distributed manually for 30 seconds, then left on for 1.5 minutes, for a total exposure time of two minutes. The hair swatch was rinsed under running DI water for two minutes. The experimental shampoo and conditioner samples were formulated by Colgate- Palmolive Company. Their compositions are shown in Table II. Table I Sample Identification Bleach treatment Grooming sequence Code assignment Untreated hair 10 X 2' in 6% H202 4 hours in 6% H202 None U0 Combing U 1 Shampooing U2 Shampooing/combing U3 Shampooing/conditioning/combing U4 None 2B0 Combing 2B 1 Shampooing 2B2 Shampooing/combing 2B 3 Shampooing/conditioning/combing 2B4 None 4B0 Combing 4B 1 Shampooing 4B2 Shampooing/combing 4B 3 Shampooing/conditioning/combing 4B4

350 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Shampoo and Conditioner Formulations Shampoo Conditioner Ingredient % Ingredient % ALS 12.0 Cetyl alcohol 3.5 CDEA 4.0 Germ II 0.5 Germ II 0.5 CTAC 0.5 NaH2PO 4 0.3 DI H20 q.s. DI H20 q.s. (Conditioner base 358-2A) (Shampoo base 358-1A) Ten cycles of the assigned grooming sequence were applied to each hair swatch as shown in Table II. The order of swatches was randomly assigned and changed for each groom- ing cycle. The initial wetting of swatches was done in 100 ml beakers, and the samples were segregated by type so that shampoo or conditioner residues did not contact "combed only" samples. The comb was rinsed thoroughly between uses. Hair swatches were dried in air and evaluated using various techniques that will be described. EVALUATION METHODS The changes caused by bleaching, perming, and grooming were evaluated in terms of both surface and structural properties. Surface properties were evaluated by microfluo- rometry and SEM, and surface wettability by the Wilhelmy balance method. The structural or bulk properties evaluated were dye diffusion, amino acid composition (especially cysteic acid content), mechanical properties, and fatigue behavior. Surface evaluations Microfiuorometry. Bleached hair samples were treated for ten minutes at room tempera- ture in a 0.005% aqueous Rhodamine B solution brought to pH 3.3 with acetic acid, then rinsed for three seconds in distilled water. For the grooming studies, a treatment time of 90 seconds was used. Cross-sectional and longitudinal microfluorometric studies were carried out using a Leitz MPV 1.1 microspectrophotometer with a PLOEMOPAK attachment. The PLOEMO- PAK attachment contains filter blocks dedicated to various narrow and wide band ranges specific for excitation of molecules fluorescing at various wavelengths. Scanning electron microscopy. A JSM-2 instrument (JOEL Company) was used for the determination of surface features. The samples were gold-coated to a thickness of ap- proximately 80-100 it. Wettability. The Wilhelmy balance technique (8) was used to determine single-fiber wettability. A Cahn D200 microbalance was used, with water as the wetting liquid. The wettability scans were made in the with-scale direction, and 3 mm of the fiber surface were scanned at a speed of 3 Ixm/sec. Fiber perimeters were determined by measuring wetting behavior in hexadecane.