The key details to know:
1. Benzalkonium chloride hand sanitizer was associated with a reduction in colony-forming units at three different time points.
2. Ethanol hand sanitizer was significantly less effective.
3. Researchers concluded, "These results show a major improvement in persistent antibacterial activity for the benzalkonium chloride formulation compared to the comparator ethanol-based formulation."
Researchers sought to determine the persistence of antibacterial activity of hand sanitizers by comparing one with a non-alcohol-based formulation using benzalkonium chloride (BK) (0.12%) vs one with an ethanol-based formulation (63%) (comparator product). They used a technique modification prescribed in American Society for Testing and Materials protocol E2752-10 to measure the persistence of antibacterial activity against Staphylococcus aureus at up to 4 hours after application. Outcomes revealed a noticeable reduction in colony-forming units with the application of the test product (BK) at each of the three-time points tested (3.75-4.16-log10 reductions), while the comparator produced less than 1-log10 reduction over the same period. These results indicate that the BK formulation has significantly improved persistent antibacterial activity vs the comparator ethanol-based formulation.
Evaluation of a benzalkonium chloride hand sanitizer in reducing transient Staphylococcus aureus bacterial skin contamination in health care workers: The results showed a significant reduction in total bacterial colony counts of S aureus during the week of BZK use as compared with the week of 70% ethanol sanitizer use. Read Report
PDF study performed by the American Journal of Infection control also shares the benefits of using BK rather than an alcohol-based sanitizer.