The Effect of pH on Sodium Lauryl Sulfate Irritancy Potential

Five volunteers received patch tests with 5% sodium lauryl sulfate (SIS) in solutions of differing pH. The irritant effect was monitored by visual scoring as well as by a laser Doppler vlelocimeter, evaporimeter, cutometer, and colorimeter.

The non-invasive methods used in this study with the exception of the cutometer were effective in the evaluation of skin irritation. No significant differences in the skin responses to SIS in different pH solutions were found either clinically or by the non-invasive methods used for quantification. It was concluded that the pH of SIS is not a major factor in the degree of skin irritation produced by SIS.