Demonstrating the persistent antibacterial efficacy of a hand sanitizer containing benzalkonium chloride on human skin at 1, 2, and 4 hours after application

Am J Infect Control. 2019 Aug;47(8):928-932. doi: 10.1016/j.ajic.2019.01.004. Epub 2019 Feb 16.


Background: Use of hand sanitizers has become a cornerstone in clinical practice for the prevention of disease transmission between practitioners and patients. Traditionally, these preparations have relied on ethanol (60%-70%) for bactericidal action.

Methods: This study was conducted to measure the persistence of antibacterial activity of 2 preparations. One was a non-alcohol-based formulation using benzalkonium chloride (BK) (0.12%) and the other was an ethanol-based formulation (63%) (comparator product). The persistence of antibacterial activity was measured against Staphylococcus aureus using a technique modification prescribed in American Society for Testing and Materials protocol E2752-10 at up to 4 hours after application.

Results: The test product (BK) produced a marked reduction in colony-forming units at each of the 3 time points tested (3.75-4.16-log10 reductions), whereas the comparator produced less than 1-log10 reduction over the same time. The differences were highly significant.

Discussion: In the course of patient care or examination, there are instances where opportunities exist for the practitioner's hands to become contaminated (eg, key boards and tables). Persistent antibacterial activity would reduce the chances of transfer to the patient.

Conclusions: These results show a major improvement in persistent antibacterial activity for the BK formulation compared to the comparator ethanol-based formulation.

Keywords: ASTM E2752-10; Antibacterial; Ethanol; Nosocomial infection; Persistence; Staphylococcus aureus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Infective Agents, Local / pharmacology*
  • Bacteria / drug effects*
  • Benzalkonium Compounds / pharmacology*
  • Disinfectants
  • Female
  • Hand Disinfection / methods*
  • Hand Sanitizers / pharmacology*
  • Humans
  • Male
  • Middle Aged
  • Skin / microbiology
  • Time Factors
  • Young Adult


  • Anti-Infective Agents, Local
  • Benzalkonium Compounds
  • Disinfectants
  • Hand Sanitizers