CLEANING HAIR 339 + SLES-2 A ALS lOO o E 90 70 60 i .50 • I 21.1 26.7 32.2 37.8 43.3 Temperature (C) Figure 1. Wool swatch data: Sebum removal vs temperature for ALS and SLES-2, one soil/wash cycle. COMPARISON OF HAIR AND WOOL DATA Table I presents data for the total sebum removed from hair at the two test temperatures compared with the analogous wool swatch/sebum values. Also shown are the values previously found for hair washed at 43øC (1). The SLES-2 data are in excellent agree- ment for both hair and wool (standard deviations are small). At the lower temperature, the agreeement is not as good (between the substrates), although values are comparable. One might expect the hair value to be higher than that of wool (as found), since intu- itively it should be easier to remove soil from the hair fibers, which are relatively untangled, as compared to the highly interwoven wool fibers. For ALS the agreement is again excellent for the hair in the 43øC experiments and is lower at 21øC for both keratin substrates. Table I Comparison of Total Sebum Removal Values From Hair and Wool Substrates (2 iøC and 43øC Data) Total sebum removed (%) Hair • Hair 2 Wool Hair Wool (43) (43) (43) (21) (21) SLES-2 90 ñ 23 92 ñ 3 90 ñ 2 71 ñ- 5 57 ñ- 4 ALS 64 ñ 18 64 ñ 8 85 ñ 2 46 ñ 6 55 ñ- 3 Data from the present work. Data from reference 1. Mean ñ SD.

340 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS HAIR DATA A two-way analysis of variance performed on the total sebum removal data shows signif- icant differences between surfactants (p = 0.0002) and temperatures (p = 0.002), but p = 0.93 for the surfactant/temperature interaction, showing that surfactant effects at one temperature are essentially the same at other temperatures. Previous data (1) revealed that no surfactant was more selective than another for the removal of sebum components from hair. The detergency of the three surfactants tested in reference 1 followed the rules of surfactant theory (4). To determine if there is selec- tivity for removal of sebum components by a surfactant when the temperature is low- ered from 43øC to 2 IøC, one-way ANOVA statistics have been used to analyze the data. Seven sebum components were analyzed, i.e., myristic (C•4), palmitic (C•6), stearic (C•8), and unsaturated (oleic and linoleic) acids (C•8:2•) cholesterol (CHOL) paraffin waxes (P.W.) (11 fractions combined) and esters (EST) (from spermaceti wax five fractions combined). ALS-WASHED HAIR Figure 2 illustrates the differences in sebum component removal at the two tempera- tures removal at 2 IøC is significantly different from removal at 43øC (p = 0.05). The following also compares component removal by ALS at the two temperatures (statistical criterion, p = 0.05): • ALS/21C • ALS/43C 100 80 60 40 20 0 C14 C16 C18:21 C18 CHOL P.W. EST Sebum Component Figure 2. Removal of sebum components by ALS: Ten soil/wash cycles, 2 IøC and 43øC.