Quantity of soap as a variable in handwashing

Area of Science:

• Microbiology
• Infection Control
• Public Health

Background:

• Hand hygiene is critical for preventing healthcare-associated infections.
• The amount of handwashing product used can influence microbial reduction.
• Variability in soap usage among healthcare professionals is not well understood.

Purpose of the Study:

• To evaluate the impact of different handwashing product volumes (1 mL vs. 3 mL) on microbial load reduction.
• To assess the effectiveness of various handwashing agents, including antiseptic soaps and alcohol-based hand rinses.
• To quantify the amount of liquid soap dispensed and used by hospital personnel during handwashing.

Main Methods:

• Randomized controlled trial involving 40 subjects washing hands with four different products in 1 mL or 3 mL volumes.
• Microbial colony-forming units (CFU) were measured before and after handwashing over five days.
• A survey assessed liquid soap usage among 47 hospital staff and 10 general population individuals.

Main Results:

• All tested handwashing products significantly reduced log CFU compared to baseline.
• Using 3 mL of antiseptic soap resulted in greater microbial reduction than 1 mL (P < 0.001).
• Soap usage varied from 0.4 to 9 mL per wash, with higher use in high-risk clinical areas (P < 0.05).

Conclusions:

• The volume of handwashing product is a significant determinant of microbial reduction on hands.
• Antiseptic soap efficacy is dose-dependent, unlike non-antimicrobial soap.
• Healthcare personnel exhibit considerable variation in liquid soap consumption, impacting hand hygiene consistency.