surgical scrub with brushASTM E1115 Evaluation of Surgical Hand Scrub Formulations

The ASTM E1115 test uses what are called glove juice sampling techniques to measure the reduction of immediate and persistent bacteria on hands after single or multiple treatments using Surgical Hand Scrub products. For this testing a supervised surgical scrub is completed before one hand for each subject is immediately tested. 6 hours after the surgical scrub treatment the second hand is tested for surviving microorganisms. If the cumulative antibacterial effect of the surgical scrub is to be evaluated, testing may be continued over the course of a 5-day period to profile the cumulative effect of using the product.

ASTM E1115: Procedure at a glance

In this study, healthy subjects with high levels of bacterial flora are chosen from a group of study participants who have not used antimicrobial products for the week preceding the test. An initial 7-day "Baseline Period," which includes three non-antimicrobial washing, sampling, and enumeration steps is used to obtain the baseline hand bacterial populations. Subjects with ≥ 1 x 105 CFU/hand at each sampling time are selected as test subjects.

A balanced randomized plan is then used to test a group of at least six test subjects. These subjects must have completed the "Baseline Period" 24-96 hours before they perform the perscribed surgical scrub treatment with the test formulation. Subject hands are then sampled for surviving microorganisms zero, three, and six hours after the treatment wherein the three hour sampling interval is optional and where samples are recovered using the glove juice sampling technique. The immediate activity measurements are the results obtained immediately following a single scrub (zero hour sampling interval). Persistent activity, or a continuing antimicrobial effect, is measured using the data from the later samplings. In order to obtain cumulative effect measurements, the hands may be sampled after completing 11 additional scrubs with the antimicrobial product over a 5 day period.

The average number of surviving microorganisms recovered for each hand sampled at each sampling time are calculated, and the changes from the baseline counts are determined. The mean log10 reduction, coupled with 95% confidence intervals for the test formulation performance are calculated. For persistent and cumulative activity, analysis of variance techniques are used to evaluate differences between sampling intervals. The validity of the test method within a study is determined using an internal reference formulation and a negative control.

ASTM E1115: EUROFINS CRL’S EXPERTISE

Eurofins CRL was founded in 2017 as a collaborative effort between two specialty contract testing facilities. ECRL combines the expertise derived from its legacy with the innovative methods and quality focus that makes the Eurofins name a leader in third-party testing world-wide. 

Eurofins CRL Is:

A contract testing laboratory designed to support the hand hygiene and infection control industry. Testing is carried out in compliance with current FDA, Good Laboratory Practice (GLP), and Good Clinical Practice (GCP) regulations by skilled, experienced microbiologists and chemists, to quickly meet your project testing goals.

Eurofins CRL Is:

An FDA GLP and GCP-compliant testing organization staffed by skilled, experienced microbiologists and subject recruiters.  ECRL can help speed your project to completion.