Comparative Efficacy of Hand Rubs Containing Alcohol or Quaternary Ammonium Compounds Sarah Edmonds 1, Collette Duley 2, Robert McCormack 2, David Macinga 1 1 GOJO Industries, Inc, 2 BioScience Laboratories, Inc.
Background Typical active ingredients in hand rubs include alcohol (ethanol, isopropanol) or quaternary ammonium compounds (benzalkonium chloride, benzethonium chloride) Hand rubs containing alcohol at a concentration of 70%-90% are recommended for use when hands are not visibly soiled 1 In healthcare hand rubs based on quaternary ammonium compounds are not recommended and should not be used 1 Quaternary ammonium compounds are occasionally used in special healthcare populations due to concerns of flammability and ingestion 1 Provincial Infectious Diseases Advisory Committee (PIDAC) Best Practices for Hand Hygiene In All Health Care Settings, December 2010.
Study Objectives Compare the efficacy of various hand rub formulations, including alcohol-based and quaternary ammonium compound based formulations
Test Products Product Code Active Ingredient Product A 70% ethanol gel Product B 0.13% benzalkonium chloride foam Product C 0.20% benzalkonium chloride gel Product D 0.13% benzalkonium chloride foam Product Format
Test Method: ASTM E 1174 Contaminate hands with 10 9 cfu Serratia marcescens Sample hands to obtain baseline level Contaminate hands again and apply test product Sample hands to obtain post exposure level Perform a total of 9 additional contamination and product application cycles Sample hands after final (10 th ) product application Products A, B, and C tested at a volume of 2 ml, rubbed in until dry Health Canada Endpoints: Bacterial Reduction (log 10 ) 1st Application: 3 log 10th Application: 3 log ASTM International. E-1174-06: Standard test method for evaluation of the effectiveness of health care personnel or consumer handwash formulations. 5
Test Method: ASTM E 2755 2 1 Centrifuge culture at 7000 G for 10 minutes and resuspend in 1:10 volume of fresh broth 3 Grow S. marcescens at 35 C with vigorous shaking (~ 10 10 cfu/ml) 4 Dispense 0.2 ml of S. marcescens into the subjects cupped hands. Rub contamination into all surfaces of hands for 30 sec. Products A and D tested at a volume of 1.5 ml, rubbed in until dry Product applications repeated 11x with sampling after Applications 1 and 11 ASTM International. E-2755-10: Standard test method for determining the bacteria-eliminating effectiveness of hand sanitizer formulations using hands of adults.
E 1174 Results (2 ml dose) Log 10 Reduction from Baseline 5 4 3 2 1 0 4.22 4.09 3.57 3.35 2.99 2.02 1.81 1.68 Product A 1 Product B 1 Product A 2 Product C 2 Health Canada Requirement Application 1 Application 10 1 Tested in Study 1, 2 Tested in Study 2 Error Bars Represent 95% Confidence Intervals Only the alcohol hand rub met Health Canada requirements 1 for a 3 log reduction Product A with 70% ethanol was statistically superior to Products B and C at applications 1 and 10 1 Health Canada Guidance Document Human-Use Antiseptic Drugs, November 2009.
E 2755 Results (1.5 ml dose) Log 10 Reduction from Baseline 6 4 2 0 2.34 4.37 Product A 1.70 1.28 Product D Application 1 Application 11 Error Bars Represent 95% Confidence Intervals Product A with 70% ethanol was statistically superior to Product D at applications 1 and 11
Summary & Conclusions The 70% ethanol ABHR, Product A, was the only product to meet Health Canada requirements for antiseptic drugs used in healthcare. The ABHR was statistically superior to all 3 quaternary ammonium based hand rubs tested after both a single use and multiple uses, using 2 different test methods These results help support PIDAC recommendations to only use 70-90% ABHR in hospital settings and to not use quaternary ammonium compounds in healthcare settings.
Summary & Conclusions If you choose to use a quaternary ammonium compound based hand rub in your facility you should do so cautiously as the antimicrobial efficacy of the product may not be sufficient
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