ASTM E2471-05

Standard Test Method for Using Seeded-Agar for the Screening Assessment of Antimicrobial Activity In Carpets

SIGNIFICANCE AND USE
This test method provides for rapid screening of antimicrobial treatments located in or on the carpet face fiber or incorporated into the backing structure of the carpet (or both).
This test method simulates actual use conditions that may occur on carpets (for example, food and beverage spills, soiling from foot traffic, prolonged moisture exposure).
This test method provides a means to screen for activity and durability of an antimicrobial treatment under conditions of organic loading.
This test method provides for the simultaneous assessment of multiple carpet components for antimicrobial activity.
Carpets may be cleaned prior to testing with this test method in order to assess the durability of the antimicrobial effect.
SCOPE
1.1 This test method is designed to evaluate (qualitatively) the presence of antimicrobial activity in or on carpets. Use this test method to qualitatively evaluate both antibacterial and antifungal activity.
1.2 Use half strength (nutrient and agar) tryptic soy agar as the inoculum vehicle for bacteria and half strength potato dextrose agar as the inoculum vehicle for mold conidia. Use of half strength agars may reduce undue neutralization of an antimicrobial due to excessive organic load.
1.3 This test method simultaneously evaluates (both visual and stereo-microscopic) antimicrobial activity both at the fiber layer and at the primary backing layer of carpet.
1.4 Use this test method to assess the durability of the antimicrobial treatments on new carpets, and on those repeatedly shampooed or exposed to in-use conditions.
1.5 Knowledge of microbiological techniques is required for the practice of this test method.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Oct-2005
• ICS: 07.100.99 - Other standards related to microbiology
• ICS: 97.150 - Floor coverings
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.15 - Antimicrobial Agents

Relations

• Replaced By: ASTM E2471-05(2011)e1 - Standard Test Method for Using Seeded-Agar for the Screening Assessment of Antimicrobial Activity In Carpets
• Effective Date: 01-Mar-2011
• Referred By: ASTM E3152-23 - Standard Guide for Standard Test Methods and Practices Available for Determining Antifungal Activity on Natural or Synthetic Substrates Treated with Antimicrobial Agents
• Effective Date: 01-Nov-2005
• Referred By: ASTM E2966-14(2019) - Standard Test Method for Quantitative Assessment of Sanitizing Solutions for Carpet
• Effective Date: 01-Nov-2005
• Referred By: ASTM D7799-12a(2021) - Standard Specification for Tufted and Woven Broadloom Carpet Adhesives Without Homogenous PVC or Non-PVC Backings
• Effective Date: 01-Nov-2005

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2471 – 05
Standard Test Method for
Using Seeded-Agar for the Screening Assessment of
Antimicrobial Activity In Carpets
This standard is issued under the fixed designation E2471; 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.
INTRODUCTION
Today’s modern commercial carpets (especially modular carpet tile) often incorporate antimicrobial
agents either in or on the face fibers or incorporated into the primary backing (attachment point of
carpet fiber to the backing structure). The American Association of Textile Colorists and Chemists
(AATCC) Method 174 permits both qualitative and quantitative antibacterial assessment and
antifungal assessment (qualitative only) of antimicrobial treatments in or on carpet. However, the
method is not suited for rapid screening of antimicrobials low in water solubility or that have slow
diffusion rates when incorporated into the carpet’s primary backing layer. The test method described
here provides a rapid screen of antimicrobial activity in or on carpets and allows for the simultaneous
assessment of multiple components of the carpet (not just the fibers).
1. Scope 2. Referenced Documents
1.1 This test method is designed to evaluate (qualitatively) 2.1 American Association of Textile Colorists and Chemists
the presence of antimicrobial activity in or on carpets. Use this (AATCC) Standard:
test method to qualitatively evaluate both antibacterial and Method 174-1998, Antimicrobial Activity Assessment of
antifungal activity. Carpets
1.2 Use half strength (nutrient and agar) tryptic soy agar as
3. Terminology
the inoculum vehicle for bacteria and half strength potato
dextrose agar as the inoculum vehicle for mold conidia. Use of 3.1 Definitions:
3.1.1 face fiber, n—the wear layer of the carpet; can be
half strength agars may reduce undue neutralization of an
antimicrobial due to excessive organic load. composed of nylon, polypropylene, wool, or other natural or
synthetic polymers. Typically, face fiber is tufted into a woven
1.3 This test method simultaneously evaluates (both visual
and stereo-microscopic) antimicrobial activity both at the fiber ornon-wovenscrimandthencoatedwithlatextobondtheface
fiber securely to the backing; this latex coated scrim forms the
layer and at the primary backing layer of carpet.
1.4 Use this test method to assess the durability of the primary backing.
3.1.2 inoculum vehicle, n—carrier solution used to transport
antimicrobial treatments on new carpets, and on those repeat-
edly shampooed or exposed to in-use conditions. bacterial cells or mold conidia to the test substrate.
3.1.3 primary backing, n—the uppermost layer of carpet
1.5 Knowledge of microbiological techniques is required
backing where carpet fiber bundles are physically attached at
for the practice of this test method.
1.6 This standard does not purport to address all of the the base to the backing structure. This layer is typically
constructed of synthetic latex (ethylene vinyl acetate, styrene
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- butadiene, or a thermo-polymer; that is, ethylene vinyl acetate
hot-melt adhesive).
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 3.1.4 seeded agar, n—a thin layer of molten (liquid) micro-
biologicalagarcontainingeitherbacterialcellsormoldconidia
(spores) used to challenge a test substrate.
This test method is under the jurisdiction of ASTM Committee E35 on
Pesticides and is the direct responsibility of Subcommittee E35.15 onAntimicrobial
Agents. Available from American Association of Textile Chemists and Colorists
Current edition approved Nov. 1, 2005. Published November 2005. DOI:
(AATCC), One Davis Dr., P.O. Box 12215, Research Triangle Park, NC 27709-
10.1520/E2471-05.
2215.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E2471 – 05
4. Summary of Test Method 6.18 Sterile Funnel, with a glass wool plug.
6.19 Counting Chamber (hemocytometer).
4.1 Cut carpet samples into small rectangular pieces either
6.20 Light Microscope, 10 and 403 objectives
via a carpet knife or mechanical die and press. Shave half of
6.21 Disposable Latex Examination Gloves.
the face fiber on each sample using electric hair clippers and
arrange in sterile Petri dishes (typically with the shaven half of
7. Reagents
thesamplefacingthecenterofthedish.Coolmoltenagars(full
or partial complement) to 45 6 2°C and inoculate with the
7.1 Media:
challenge bacteria or mold conidia. Following wrist action
7.1.1 Tryptic Soy Broth.
mixing, immerse samples into the seeded-molten agar, place
7.1.2 Tryptic Soy Agar.
into a Petri dish and pour additional seeded agar into the dish
7.1.3 Potato Dextrose Agar.
to surround but not cover the test sample. Incubate the Petri
7.1.4 Sterile 0.85 % Saline, with 0.1 % Tween 80.
dish for 24 to 72 h at 30 6 2°C. Visually and microscopically
7.2 Test Organisms—Specific organisms are recommended
examine both at the face fiber and shaven (primary backing)
however other microorganisms may be used to mimic those
layer for inhibition of the challenge microorganisms. Report
found in a specific environment or those expected contami-
the presence of carpet surface inhibition (for low water soluble
nants which may be present where the carpet is expected to
or slow migrating antimicrobials) or zone of inhibition for
perform.
water soluble antimicrobials.
7.2.1 Gram-positive bacteria Staphylococcus aureus ATCC
6538.
5. Significance and Use
7.2.2 Gram-negative bacteria Serratia marcescens ATCC
5.1 This test method provides for rapid screening of anti-
14756.
microbial treatments located in or on the carpet face fiber or 7.2.3 Fungus Aspergillus niger ATCC 9642.
incorporated into the backing structure of the carpet (or both).
5.2 This test method simulates actual use conditions that
8. Procedure
may occur on carpets (for example, food and beverage spills,
8.1 Grow 18 hour tryptic soy broth cultures of Staphylococ-
soiling from foot traffic, prolonged moisture exposure).
cus aureus at 37 6 2°C and Serratia marcescens in tryptic soy
5.3 This test method provides a means to screen for activity
broth at 30 6 2°C. These cultures should originate from 18 to
and durability of an antimicrobial treatment under conditions
24 h growth
...