SURFACTANT INTERACTIONS 275 Table VII Commercial Conditioner Treatments of Permed Hair •'2 Treatment Shine 3 SODS Conditioner A4/SODS Conditioner A/TEALS 2.57 (0.28) 2.58 (0.06} 2.08 (0.05) Shine values connected by a vertical line were not significantly different. The angle of incidence in these experiments was 45 ø . Numbers in parentheses are standard deviations. This is a commercial conditioner containing SAC and ceteth-2. Commercial conditioner half-head tests. A series of half-head tests was run with conditioner A to determine if the treatment differences noted for tresses could be observed on heads of permed hair. In these experiments, following conditioner treatment, one side of the head was washed with TEALS while the other side was washed with SODS. Overall, a total of 26 half-head tests evaluating cleaning of conditioner A were run. The most consistent subjective differences found in these tests were associated with shine and the existence of a coated feel to the hair on one side of the head. In 23 of the 26 half-head tests, the evaluators chose the SODS-treated half of the head as being the cleaner side. In the three cases where this was not true, the TEALS side may have been chosen because of the previously mentioned orientation effects. Even dis- counting this possibility, however, statistical analysis indicates a difference between the TEALS and SODS sides at a greater than 99% level of confidence. The greater shine of the SODS-washed hair was also supported by the light-scattering results. Table VIII lists those half-head tests for which instrumental measurements were performed. For 10 of the 11 measurements, the SODS side had the higher shine value, while for the eleventh test, the shine values were essentially equal. Table VIII Commercial Conditioner (Conditioner A) Half-Head Tests. • (SODS vs TEALS) Test no. Subjective 2 shine Delta 3 shine 11 + 0.74 114 q- 0.50 124 - 0.74 13 + 0.15 14 + 0.37 144 + 0.88 154 + 0.61 164 + 0.26 174 + 0.23 184 + -- O. 07 194 + 0.23 • The angle of incidence in these experiments was 45 ø. All subjects had permed hair. 2 A positive sign means SODS-treated side judged shinier. 3 This is the difference between shine values measured for SODS and TEALS-treated sides. A positive value means SODS side had greater shine. 4 Conditioner was last treatment prior to viewing and hair sampling.

276 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS These results confirm that for commercial products as well as for SAC, the superior cleaning of conditioners by shorter-chain surfactants such as those found in SODS can be observed under conditions similar to actual consumer use. Commercial conditioner/detergent radiotracer experiments. As was done with conditioner ac- tives, radiotracer experiments were run with conditioner A doped with [•4C]SACL in order to confirm the light-scattering results and also to obtain an idea of relative amounts of deposition. The results of these experiments are tabulated in Tables IX and X. Unlike the case with conditioner actives, it is seen that both ALS and SODS are equally effective in cleaning SAC deposited from conditioner A. In addition, the amount of SAC left on the hair is approximately the same after one or two treatment cycles, indicating that, at least in this limited case, SAC did not build up on the surface of the swatch. Interaction between ALS and the SAC in conditioner A still occurs, however. This is indicated by the fact that binding of ALS to conditioner A-treated swatches was more than three times greater than binding to clean swatches. Such deposition, replacing as it does, cleaned conditioner, greatly reduces the net cleaning by ALS. This situation is made worse by buildup of ALS with repeated treatment: after three conditioner/wash cycles, ALS deposition was 28% greater than after one cycle. The increased binding of ALS to conditioner-treated swatches was not exhibited by SDES-3. In Table IX it is seen that the same amount of SDES-3 was deposited on clean swatches as on conditioner A-treated swatches, indicating, as was seen in the light- scattering experiments, that SDES-3 does not interact with conditioner A to form insoluble complexes on keratin surfaces. Table IX also lists the results of experiments in which the conditioner A/SDES-3 treatment cycle was applied to swatches three times. No increase in SDES-3 deposition Table IX Deposition From Detergent Cleaning of Commercial Conditioner: Radiotracer Measurements •'2 Treatment SAC per gram wool (mg) Detergent per gram wool (mg) No. cycles Conditioner A 3 -- Cond. M5% SODS 3 Cond. M5% hLS 3 -- Cond. M5% SODS 3 -- Cond. M5% ALS 3 -- 5% ALS 4 1.18 (0.08) Cond. M5% ALS 4 3.57 (0.13) Cond. M5% ALS 4 3.79 (0.18) Cond. M5% ALS 4 4.58 (0.19) 5% SDES-34 1.11 (0.19) Cond. A/5% SDES-34 1.08 (0.08) Cond. A/5% SDES-34 1.17 (0.30) Cond. M5% SDES-34 0.98 (0.31) 4.27 (0.59) 1.83 (0.67) 1.67 (0.24) 2.05 (0.56) 2.03 (0.55) -- -- -- -- -- __ -- -- Numbers in parentheses are standard deviations. Measured values connected by a vertical line were not significantly different. 0.3 ml of each treatment was applied. 0.15 ml of each treatment was applied.