ASTM E1874-22e1

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