Determination of Bacteria-Eliminating Effectiveness ASTM E2755

Scope:

ASTM E2755 is a test method used for evaluating health care personnel hand rubs (hand sanitizers) for their efficacy in eliminating bacteria from experimentally contaminated hands after a single application and after repeated applications. This test method can be used to test any form of hand rubs, including gels, rinses, sprays, foams, and wipes when used according to label directions at typical “in-use” doses.

Test Procedure:

ASTM E2755 test is conducted using the healthy hands of at least eight study participants who have not used antimicrobial products for at least one week before testing. Following an initial cleansing wash, the participants’ hands are thoroughly contaminated with a test microorganism such as Serratia marcescens or Staphylococcus aureus and the starting baseline number of microorganisms is determined. After the baseline bacterial sampling, participants’ hands are again subject to a cleansing wash and inoculation. A hand rub product is then applied full strength to dry contaminated hands and the hands are rubbed thoroughly until the product dries. A rinse step is not included. The activity of the product is determined following a single contamination/antiseptic exposure cycle, simulating a situation where hand sanitizers are used only occasionally. The multiple application test determines if there is any impact on the activity of the hand sanitizer due to a build-up of non-volatile components on the surface of the hands following repeated use. A reference control test procedure is included so that the effectiveness of different hand rub products can be compared. At last , the baseline and surviving microorganisms are recovered using glove or plastic bag methods and the bacteria are enumerated using standard techniques and then the average number of microorganisms recovered after each test is calculated.

Specimen Size:

According to ASTM E2755, plastic bags can be used in place of gloves and should be approximately 29 by 31 cm, and possesses no antimicrobial properties.

Tap water temperature should be maintained at 40 ± 2°C.

Sterilizable container having tight closure and sufficient capacity to hold 75 ml sampling solution.

Data:

The effectiveness of the hand rub is determined by comparing the number of microorganisms recovered from contaminated hands after the use of the antiseptic product to the number recovered from contaminated hands that were not exposed to a hand rub product.

The effectiveness of the hand rubs is reported in SI units and is considered as standard.