ASTM E640-06(2019)

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.
Designation: E640 − 06 (Reapproved 2019)
Standard Test Method for
Preservatives in Water-Containing Cosmetics
This standard is issued under the fixed designation E640; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance
1.1 This test method covers the determination of the suit- 4.1 This test method should be used to determine if a
abilityofpreservativesforuseincosmeticformulations.Itsets preservative or preservative system has application for the
preservation of water-miscible cosmetic products.
minimal requirements for preservative performance in model
formulations.
5. Materials
1.2 The values stated in SI units are to be regarded as
5.1 Test Formulations—Formulations that the submitter
standard. No other units of measurement are included in this
feels are appropriate for demonstration of preservative activity
standard.
shall be included in the test. Non-preserved (control) samples
1.3 This standard does not purport to address all of the
of these formulas shall also be included. Incompatibility of the
safety concerns, if any, associated with its use. It is the
preservative(s) with any of the formulations or formulation
responsibility of the user of this standard to establish appro-
components shall be noted.
priate safety, health, and environmental practices and deter-
5.2 Test Microorganisms (Suggested Panel):
mine the applicability of regulatory limitations prior to use.
5.2.1 Other test microorganisms or equivalent species may
1.4 This international standard was developed in accor-
be included as appropriate and if standardized cultures from
dance with internationally recognized principles on standard-
cosmetic isolates become available. The primary function of
ization established in the Decision on Principles for the
these cultures is to provide a common basis for comparison of
Development of International Standards, Guides and Recom-
different preservatives.
mendations issued by the World Trade Organization Technical
5.2.1.1 Pseudomonas aeruginosa ATCC 9027.
Barriers to Trade (TBT) Committee.
5.2.1.2 Burkolderia cepacia ATCC 25416.
5.2.1.3 Escherichia coli ATTC 8739.
2. Referenced Documents
5.2.1.4 Staphylococcus aureus ATCC 6538.
2.1 ASTM Standards:
5.2.1.5 Candida albicans ATCC 10231.
E1054Test Methods for Evaluation of Inactivators of Anti-
5.2.1.6 Enterobacter gergoviae ATCC 33028.
microbial Agents
5.2.1.7 Aspergillus niger ATCC 16404.
5.2.1.8 Eupenicillium levitum ATCC 10464.
3. Summary of Method
5.2.2 If available, cosmetic spoilage microorganisms and/or
3.1 This test method involves a microbiological challenge
microorganisms obtained from the cosmetic manufacturing
test of preservatives incorporated into model formulations at
environment may be used in addition to those microorganisms
recommended efficacy levels. Routine microbiological proce-
suggested in 5.2.
dures are used to determine the antimicrobial activity of
5.3 Culture Maintenance—The microorganisms listed in
preservativesinformulations.Thismethodrequirestheknowl-
5.2.1 shall be maintained as specified by ATCC.
edge of standard microbiological techniques.
5.3.1 PlatingDiluents—Platingdiluentsareusedtodisperse
the test sample in preparation for plating and, if necessary, aid
in neutralizing the preservative present to permit the optimum
This test method is under the jurisdiction of ASTM Committee E35 on
recovery of surviving microorganisms. The choice of diluents
Pesticides, Antimicrobials, and Alternative Control Agentsand is the direct respon-
is dependent of the diluents ability to meet the neutralization
sibility of Subcommittee E35.15 on Antimicrobial Agents.
requirements specified in 5.3.3. The following suggested di-
Current edition approved Jan. 1, 2019. Published January 2019. Originally
luents have been found to be suitable for this purpose:
approvedin1978.Lastpreviouseditionapprovedin2012asE640–06(2012).DOI:
10.1520/E0640-06R19.
5.3.1.1 Buffered 1% Peptone in physiological saline
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(0.85% NaCl).
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.3.1.2 Dey/Engley (D-E) neutralizing broth.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.3.1.3 Eugon Broth.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
E640 − 06 (2019)
5.3.1.4 Letheen Broth. using a verified aerobic fungal plate count. Harvested mold
5.3.1.5 Modified Letheen Broth. spore cultures may be used immediately or stored at 2 to 5°C
for up to four weeks.
5.3.1.6 Nutrient Broth.
6.1.4 Preparation of Inocula:
5.3.1.7 Phosphate Buffer (pH 7.0).
6.1.4.1 Mixed Culture Method:
5.3.1.8 TAT Broth.
(1)Mixed Bacteria—Mix equal portions of selected bacte-
5.3.1.9 Trypticase Soy Broth.
ria and label “Bacteria 1.”
5.3.2 Recovery Media—Arecovery medium should provide
(2)Optional Mixed Bacteria Pools—Mix separate bacteria
adequate nutritional support for the growth of the selected test
pools for gram-positive bacteria, gram-negative fermenter
microorganisms.Thefollowingsuggestedagarrecoverymedia
bacteria, and gram-negative non-fermenter bacteria. Pooled
have been found to be suitable for this purpose:
cultures may be used immediately or stored at 2 to 5°C for up
5.3.2.1 For Bacteria:
to 72 hours.
EugonAgar
LetheenAgar (3)Fungi (Mold and Yeast)—Mix equal parts of fungal
Microbial ContentAgar
suspensions thoroughly and label “Fungi #2.”
Modified LatheenAgar
6.1.4.2 Pure Culture Method—Optionally, challenges may
Plate CountAgar
Trypticase SoyAgar
also be performed using single (pure) cultures. If this method
ischosen,preparetheculturesusedforchallengesasdescribed
in 6.1 and use directly as described in 6.3. Label sample jars
5.3.2.2 For Fungi:
appropriately according to the test microorganisms used to
MaltAgar
challenge that sample.
MaltAgar Extract
6.1.5 Determination of Challenge Inocula Levels—Pre pare
MycophilAgar
Potato DextroseAgar
serial dilutions of the challenge inocula (6.1.4.1). Plate out in
duplicate using Letheen agar. Incubate bacteria and yeast at
5.3.3 Preservative Neutralization—
...