29 O.M.C. vs PADIMATE 0 SPF vs PERCENT SCREEN 28 27 26 25 24 23 22 21 20 19 18 17 16 15 26 2 ,3 4 5 6 7 8 9 10 PERCENT SUNSCREEN PAD.O-oxy + PAD.O-O.S. o PAD.O-HMS A OMC-OXY v OMC-HMS Figure 1A. SPF values of both groups of test lotions. CINNAMATE W/ OXY,O.S.,HMS SPF vs PERCENT SCREEN I i 11 12 x OMC-O.S. 25 24 25 22 21 2O 19 18 17 16 15 2 ,3 4 5 6 7 8 9 10 11 12 % SCREEN [] OXY + O.S. o HMS Figure lB: SPF values of octyl methoxycinnamate combinations.

SUNSCREEN COMBINATIONS AND SPF 145 29 PADIMATE 0 W/ OXY,O.S.,HMS SPF vs PERCENT SCREEN 28 27 26 25 24 25 22 21 20 19 18 17 16 15 2 5 4 5 6 7 8 % SCREEN [] OXY + O.S. o HMS Figure 1C. SPF values of padimate O combinations. I I I I 9 10 11 12 sunscreen combination. The higher the number, the most cost-effective the product. Since no two SPF numbers were exactly the same, three ranges of SPFs were evaluated. In the 15-to-18 SPF range, the padimate O/octyl salicylate combination is the most effective. The next best combination was padimate O/HMS. In the 21-to-28 SPF range, the padimate O/HMS combination was still the most cost-effective, but the second most effective was the padimate O/oxybenzone combination. By looking at all the data of Table II, one can observe that the padimate O combina- tions were clearly the most cost-effective. SUMMARY Based on these tests, we can draw the following conclusions: 1. Combinations with octyl methoxycinnamate yielded higher SPFs in the 15-to-21 SPF range than the same combinations using padimate O. 2. The highest SPF for each set was achieved using 6 percent oxybenzone. 3. The highest SPFs overall were with the padimate O combinations. 4. Octyl salicylate was more effective with padimate O than with octyl methoxycinna- mate. 5. Homosalate performed the same with padimate O and octyl salicylate.