JOURNAL OF COSMETIC SCIENCE 146 solvents using an ASE (automated solvent extraction) system. The extracts were analyzed by GC/MS using fl ame ionization detector (FID) and mass spectrometry (electron ioniza- tion (EI) mode). RESULTS AND DISCUSSION INFLUENCE OF COSMETIC TREATMENTS ON HAIR BREAKAGE After setting up the machine, hair strands treated in various cosmetic ways were tested. In Figure 2 the amount of hair breakage is given for virgin, bleached, bleached and permed, and persulfate bleached hair strands. It can be seen that the amount of broken hair fi bers increases by chemical treatments. While a bleaching with hydrogen peroxide increases the amount of broken hair by 54%, the combination of bleaching and perming more than doubles the level of hair breakage (213% related to virgin hair). By applying a persulfate bleach to the hair the amount of hair breakage is increased by 244%. All further examinations have been performed using bleached hair, as such hair is a good model for damaged hair. Using this type of pretreated hair the infl uence of the relative humidity was checked. In Figure 3 hair breakage of bleached hair is given for 40%, 60% and 75% relative humid- ity. It can be seen that the amount of hair breakage increases when going to more humid conditions by 14.5% (40% RH - 60% RH) and 20.3% (40% RH - 75% RH) Since all other tests in our lab are performed at 40% RH, this condition was kept throughout the work described in this paper. Figure 2. Hair breakage for hair strands of different cosmetic treatments. All results except for the difference of the last two columns are signifi cantly different (p0.05).

2008 TRI/PRINCETON CONFERENCE 147 DETERMINATION OF THE ANTI-BREAKAGE EFFICACY OF COMMERCIAL HAIR CARE PRODUCTS Several shampoos from major brands were tested for their anti-breakage effi cacy. The results of two shampoos from different brands, both containing dimethicone and cat- ionic polymer guar hydroxypropyltrimonium chloride, are given in Figure 4. Since the producers suggest using fi rst the anti breakage shampoo and then the related anti break- age conditioner from the same product line, this was also tested. It can be seen from Figure 3. Hair breakage of bleached hair at relative different humidities. The result for 40% is signifi cantly different from the data found for 60% and 75% RH ( p0.05). Figure 4. Hair breakage for hair strands treated with benchmark products. All results except for the differ- ence of the last two columns are signifi cantly different (p0.05).