Dr James Arbogast1, Mrs. Georgia Oxley-Smith2, Dr. Florian H. H. Brill3, Mr. Kevin Ormandy2
1JW Arbogast Advanced Science Consulting LLC, Akron, United States, 2SCJ Professional, Denby, England, 3Dr. Brill Institutes, Germany
Biography:
Dr. Arbogast has >25 years of consumer product development experience. He makes many technical conference presentations, has invented >70 patents and co-authored >55 peer-reviewed publications. All driven by his passion for reducing health outcomes risk and infection prevention, public health education, and advancing hygiene science + improving policies and practices.
Abstract:
Introduction
Effective alcohol-based hand rubs (ABHRs) are required in healthcare hand hygiene guidelines globally to prevent infections via reduced pathogen transmission. The evidence is clear that ABHR formulation impacts efficacy, and dose size impacts hand coverage. However, further study is needed to determine the optimal ABHR dose to achieve acceptable pathogen reduction, whilst balancing coverage, wet-time and user acceptance.
Methods
This study evaluated two doses of the same ABHR foam formulation on bacteria reduction with a robust in vivo method (ASTM E2755, “Determining the Bacteria-Eliminating Effectiveness of Healthcare Personnel Hand Rub Formulations Using Hands of Adults”). Test subjects’ hands were contaminated with Serratia marcescens in practicelike studies in two parts (20 people used ~1.0mL and 10 people used ~1.5mL). Mean log10 reduction of bacteria per subject was statistically analyzed by independent t-test.
Results
The 1.48 mL ABHR dose achieved a mean log₁₀ reduction of 3.30, significantly higher than the 1.03 mL dose, which achieved 2.17 (p < 0.001). Additionally, the higher dose showed reduced variability (0.56 vs. 0.86 standard deviation), indicating more consistent performance. There is no significant difference in log10 reduction between right and left hands (p > 0.05).
Conclusion
The 1.48 mL ABHR dose provided superior and more consistent antimicrobial efficacy than 1.03 mL. These findings support a 1.5 mL minimum dose to ensure effective hand hygiene performance, aligning with hand coverage requirements and in vivo reduction targets. This new evidence urges reexamination of existing ABHR dose per usage risk assessment, guidance and monitoring requirements in healthcare practice.