A Study of Effective Shampoo Technique to Decrease Bacterial Contamination

Abstract

Purpose: To devise and verify the effective shampoo technique to decrease bacterial contamination and causes little stress in the recumbent state.

Methods: We set up four different conditions which vary in hot water quantity (5/10 L) and the way of rinsing (cupping one’s hands to hold hot water and then gently shake hair in it/brushing hair with fingers in hot water). We then divided twenty healthy adults into four groups, so that five participants were tested under each of the four different conditions. Hair and scalp bacterial counts (Staphylococcus) and triglyceride (TG) levels were investigated before and after hair washing. The rate of change was calculated using before hair washing “1” as a reference.

Results: Bacterial counts decreased by 0.34 ± 0.05 when 10 L of hot water was used and the hair was gently shaken (p < 0.05). While the scalp bacterial counts decreased to below 1 for all methods, a greater decrease was seen when a larger quantity of hot water was used (p < 0.05). TG level decreased in both the hair and scalp when 10 L of hot water was used, regardless of how the hands were used. Although no significant differences were observed for subjective evaluation, rinsing after cupping the hands to hold the water tended to cause the participants to feel highly refreshed.

Conclusions: Using a large amount (10 L) of hot water and cupping the hands to hold the water to rinse the hair while gently shaking it is an effective method of hair washing to eliminate bacterial contamination.