152 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 9.0- 8.5- 8.0- 7.5- 7.0- o•6.0 - -- 5.5- 5.0- 4.5- 4.0 3.5 3.0 1 2 3 110 17 24 31 38 45 52 59 t [dl Figure 3. Development of the counts of coagulase-negative staphylococci per square centimeter on the forehead from washing with synthetic detergent preparations at pH 5.5 and 8.5. 6.0- 5.5- 5.0- 4.5- t4.0- 3.5- 3.0- 2.5- 2.0- 1.5- 0.5- 0 T T , , , // ] , , , , , , , 1 2 3 10 17 24 31 38 45 52 59 t (dJ Figure 4. Development of the counts of coagulase-negative staphylococci per square centimeter on the forearm from washing with synthetic detergent preparations at pH 5.5 and 8.5.

pH EFFECTS ON SKIN 153 9.0 8.5' 8.0- 7.5- 7.0- 6.5- 6.0- 5.5- 5.0- 3.5- 3.0 • [ [ II [ ] [ ] [ [ [ ] 1 2 3 10 17 2LI 31 38 L$5 52 59 t (d] Figure 5. Development of the counts of propionibacteria per square centimeter on the forehead from washing with synthetic detergent preparations at pH 5.5 and 8.5. 5.5- 5.0- L$ 0- 3 5- 3o- 2 5- 2 0- 1 5- 1 0- 0.5- 0 T I I • /! I I I I [ , ' ' 1 2 3 10 17 2N 31 38 N5 52 59 t (d) Figure 6. Development of the counts of propionibacteria on the forearm from washing with synthetic detergent preparations at pH 5.5 and 8.5.