ASTM E1874-22e1

Standard Practice for Recovery of Microorganisms From Skin using the Cup Scrub Technique

SIGNIFICANCE AND USE
5.1 The procedure can be incorporated into protocols used to evaluate test materials containing antibacterial ingredients that are intended to reduce significantly the number of organisms on intact skin. It also may be used to provide an indication of residual antibacterial activity (as in Guide E2752). Examples of test materials, for which this practice is applicable, include pre-operative skin preparations, hand-washes, surgical scrubs, acne reduction products, and others. For each type of test material, types of resident flora or surrogate organisms, or a combination thereof, may differ and should be considered (this is, aerobic bacteria, anaerobic bacteria, yeast, or mold).  
5.2 The procedure may be used in protocols intended to evaluate and identify resident flora from the skin.  
5.3 Performance of this technique may require the knowledge of regulations pertaining to the protection of human subjects if the protocol involves application of the technique to the skin of human subjects.
SCOPE
1.1 This practice is designed to recover microorganisms from the skin of human subjects or human subject surrogates (animal skin, isolated porcine skin, human skin equivalents, and other such surfaces).  
1.2 Knowledge of microbiological techniques is required for these procedures.  
1.3 It is the responsibility of the investigator to determine if Good Laboratory Practice (GLP) and Good Clinical Practice (GCP) is required.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2022
• ICS: 71.100.40 - Surface active agents
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.15 - Antimicrobial Agents

Relations

• Refers: ASTM E2756-19 - Standard Terminology Relating to Antimicrobial and Antiviral Agents
• Effective Date: 01-Nov-2019
• Refers: ASTM E2756-18 - Standard Terminology Relating to Antimicrobial and Antiviral Agents
• Effective Date: 01-Apr-2018
• Refers: ASTM E2752-10(2015) - Standard Guide for Evaluation of Residual Effectiveness of Antibacterial Personal Cleansing Products
• Effective Date: 01-Oct-2015
• Refers: ASTM E2756-10 - Standard Terminology Relating to Antimicrobial and Antiviral Agents
• Effective Date: 01-May-2010
• Refers: ASTM E2752-10 - Standard Guide for Evaluation of Residual Effectiveness of Antibacterial Personal Cleansing Products
• Effective Date: 01-Apr-2010
• Refers: ASTM E1054-08 - Standard Test Methods for Evaluation of Inactivators of Antimicrobial Agents
• Effective Date: 01-Apr-2008
• Refers: ASTM E1054-02 - Standard Test Methods for Evaluation of Inactivators of Antimicrobial Agents
• Effective Date: 10-May-2002

Overview

ASTM E1874-22e1: Standard Practice for Recovery of Microorganisms From Skin using the Cup Scrub Technique provides a standardized methodology for collecting and quantifying microorganisms-such as bacteria, yeast, and molds-from skin surfaces. Developed by ASTM International, this practice is applicable to human subjects as well as human skin surrogates (e.g., animal skin, isolated porcine skin, skin equivalents). It is a critical reference for researchers and product developers aiming to evaluate the effectiveness of antibacterial products and skin-cleansing agents.

This standard outlines proper use of the cup scrub technique, which enables reproducible recovery of both resident and transient microorganisms from the skin for laboratory analysis.

Key Topics

• Microorganism Recovery Technique: Describes the use of sterile scrub cups, recovery fluids with suitable neutralizers, and mechanical agitation to recover microorganisms from a defined skin area.
• Test Controls and Baseline Sampling: Highlights the importance of appropriate controls, such as test article controls, inert test samples, and baseline samples for accurate efficacy assessments.
• Sample Site Selection: Provides guidance for selecting and randomizing multiple sampling sites to minimize bias and ensure statistically reliable data.
• Safety and Regulatory Considerations: Reinforces the need for compliance with Good Laboratory Practice (GLP), Good Clinical Practice (GCP), and human subject protection regulations.
• Microbial Counts and Media: Details the process for preparing serial dilutions, plating samples, and selecting agar depending on the microorganisms targeted.

Applications

The cup scrub technique detailed in ASTM E1874-22e1 is widely adopted in microbiological and clinical research for:

• Evaluating Antibacterial Products: Used to test efficacy of pre-operative skin preparations, hand-washes, surgical scrubs, and dermatological treatments such as acne reduction products. The technique helps determine the capability of products to reduce skin microorganism loads.
• Assessing Residual Antibacterial Activity: Supports studies seeking to measure how long antibacterial effects persist on the skin after product application.
• Characterizing Skin Flora: Enables accurate identification and quantitation of resident and transient microbial populations on the skin, aiding research in dermatology and infection control.
• Protocol Integration: Compatible with both in situ (on living skin) and in vitro (on isolated or artificial skin) protocols for comprehensive evaluation in various scientific and regulatory contexts.

For each application, the standard allows flexibility in choosing test organisms and sample types, making it applicable to diverse research and product development needs.

Related Standards

• ASTM E2752: Guide for Evaluation of the Residual Effectiveness of Antibacterial Personal Cleansing Products – referenced for assessing residual activity.
• ASTM E1054: Practices for Evaluation of Inactivators of Antimicrobial Agents – outlines methods for ensuring that neutralizers effectively inactivate residual antimicrobial agents in the sampling fluid.
• ASTM E2756: Terminology Relating to Antimicrobial and Antiviral Agents – provides key definitions relevant to antimicrobial studies.
• Federal Regulations (CFR Parts 50 and 56): Protection of Human Subjects and Institutional Review Boards – essential for regulatory compliance in studies involving human participants.

Practical Value

ASTM E1874-22e1 serves as a foundational document for laboratories, clinical researchers, and product manufacturers, ensuring methodological rigor, reproducibility, and regulatory compliance. Proper use enhances data quality in the evaluation of antibacterial products, supports claims regarding skin hygiene efficacy, and safeguards human subject welfare in clinical settings.

Keywords: cup scrub, skin microbiome, microorganism recovery, antibacterial efficacy, skin cleansers, residual activity, clinical protocols, ASTM E1874-22e1

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
´1
Designation: E1874 − 22
Standard Practice for
Recovery of Microorganisms From Skin using the Cup
Scrub Technique
This standard is issued under the fixed designation E1874; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—The standard type was editorially corrected in April 2023.
1. Scope E2752 Guide for Evaluation of Residual Effectiveness of
Antibacterial Personal Cleansing Products
1.1 This practice is designed to recover microorganisms
E2756 Terminology Relating to Antimicrobial and Antiviral
from the skin of human subjects or human subject surrogates
Agents
(animal skin, isolated porcine skin, human skin equivalents,
2.2 Federal Document:
and other such surfaces).
CFR Parts 50 and 56 Code of Federal Regulations: Protec-
1.2 Knowledge of microbiological techniques is required
tion of Human Subjects; Institutional Review Boards
for these procedures.
1.3 It is the responsibility of the investigator to determine if 3. Terminology
Good Laboratory Practice (GLP) and Good Clinical Practice
3.1 Defintions—For definitions of terms used in this
(GCP) is required.
document, see Terminology E2756.
1.4 The values stated in SI units are to be regarded as
3.2 Definitions of Terms Specific to This Standard:
standard. No other units of measurement are included in this
3.2.1 contralateral, adj—on or relating to the opposite side
standard.
(of the body).
1.5 This standard does not purport to address all of the
3.2.2 scrub cups, n—sterile cylinders of suitable composi-
safety concerns, if any, associated with its use. It is the
tion (that is, glass, ceramic, stainless steel, plastic, etc.) used to
responsibility of the user of this standard to establish appro-
isolate a sample area of skin (or skin equivalent) and confine a
priate safety, health, and environmental practices and deter-
aliquot of liquid which is used to facilitate the scrubbing of the
mine the applicability of regulatory limitations prior to use.
skin and removal of microorganisms from the skin surface by
1.6 This international standard was developed in accor-
pipetting.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Summary of Practice
Development of International Standards, Guides and Recom-
4.1 This practice describes a technique suitable for the
mendations issued by the World Trade Organization Technical
recovery of resident and transient microorganisms from human
Barriers to Trade (TBT) Committee.
or animal skin; the technique may be used in situ within
clinical protocols or in vitro for studies using isolated skin or
2. Referenced Documents
skin equivalents.
2.1 ASTM Standards:
4.2 Resident and transient microorganisms and/or surrogate
E1054 Practices for Evaluation of Inactivators of Antimicro-
microorganisms (previously applied to a test site) are recovered
bial Agents
from the site by pressing a rigid cylinder against the skin with
sufficient pressure to form a seal and instilling recovery liquid
into the cylinder. The surface of the skin is then mechanically
This practice is under the jurisdiction of ASTM Committee E35 on Pesticides,
‘scrubbed’ with a polished glass rod, rubber policeman, or
Antimicrobials, and Alternative Control Agents and is the direct responsibility of
some other suitable device for a prescribed period of time. The
Subcommittee E35.15 on Antimicrobial Agents.
Current edition approved Nov. 1, 2022. Published January 2023. Originally
fluid is pipetted from the cylinder into a test tube, or other
approved in 1997. Last previous edition approved in 2014 as E1875–14. DOI:
suitable receptacle, for further analysis.
10.1520/E1874-22E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
the ASTM website. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E1874 − 22
5. Significance and Use 8.3 While designing a study following this practice, proper
controls must be taken into consideration. Some examples are:
5.1 The procedure can be incorporated into protocols used
8.3.1 Test article control—A formula similar to that under
to evaluate test materials containing antibacterial ingredients
test with antimicrobial ingredients removed.
that are intended to reduce significantly the number of organ-
8.3.2 Inert test sample—Sampling fluid used to measure the
isms on intact skin. It also may be used to provide an indication
amount of bacteria removed following sampling process.
of residual antibacterial activity (as in Guide E2752). Ex-
8.3.3 Surrogate microorganism—Similar to a baseline
amples of test materials, for which this practice is applicable,
sample including application of the study organism prior to
include pre-operative skin preparations, hand-washes, surgical
recovery.
scrubs, acne reduction products, and others. For each type of
test material, types of resident flora or surrogate organisms, or
9. Sample Site
a combination thereof, may differ and should be considered
(this is, aerobic bacteria, anaerobic bacteria, yeast, or mold). 9.1 Subjects—The number of subjects (human or animal)
required (if the protocol is in vivo) depends on the statistical
5.2 The procedure may be used in protocols intended to
confidence needed for the expected test results, the variability
evaluate and identify resident flora from the skin.
encountered in the study, and the relative efficacy of any
5.3 Performance of this technique may require the knowl-
antibacterial agent that may be evaluated. There may be
edge of regulations pertaining to the protection of human
multiple sites available on subjects; randomization is required
subjects if the protocol involves application of the technique to
to suppress sample bias.
the skin of human subjects.
9.2 Isolated Skin or Equivalents—The number of replicates
6. Apparatus
required to discriminate effects will depend in part on the
appropriateness and design of controls within the protocol.
6.1 Sterilizer—Any suitable steam sterilizer capable of pro-
9.2.1 The use of this technique on isolated skin or equiva-
ducing the conditions of sterilization.
lents is dependent on securing the test site in order to
7. Reagents and Materials
ef
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