ASTM D4576-16(2021)

Standard Test Method for Mold Growth Resistance of Wet Blue and Wet White

SIGNIFICANCE AND USE
4.1 This test method provides a technique for evaluating mold growth resistance characteristics of Wet Blue and Wet White, and should assist in the prediction of storage time before molding occurs.  
4.2 The degree of correlation between this test and commercial quantities of Wet Blue and Wet White in storage or shipment situations, or both, has not been fully determined.
SCOPE
1.1 This test method covers the determination of mold growth resistance of Wet Blue and Wet White subject to storage and shipping requirements and intended for use in leather manufacturing. This test method may not be suitable to evaluate fungicides that are inactivated by proteins. This includes alkyldimethylbenzyl ammonium chlorides.  
1.2 Conclusions about mold growth resistance are drawn from the results by comparing the test with a simultaneously run control of known resistance. Success or failure is determined by the amount of mold growth relative to the control.  
1.3 To allow use of this test method by any laboratory, flexibility has been permitted in times, temperature, and humidity of incubation, inoculum, hide sampling area, and choice of control. These may be adjusted to fit local conditions but must be standardized.  
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-Aug-2021
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.02 - Wet Blue

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.
Designation: D4576 − 16 (Reapproved 2021)
Standard Test Method for
1
Mold Growth Resistance of Wet Blue and Wet White
This standard is issued under the fixed designation D4576; 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 2.1.2 Wet White—a hide or skin, or split of a hide or skin
tanned with organic or non-organic tanning agents (excluding
1.1 This test method covers the determination of mold
chromium or iron containing agents and vegetable extracts),
growthresistanceofWetBlueandWetWhitesubjecttostorage
containing approximately 50 % moisture.
and shipping requirements and intended for use in leather
manufacturing. This test method may not be suitable to
3. Summary of Test Method
evaluate fungicides that are inactivated by proteins. This
3.1 Wet Blue and Wet White test specimens are surrounded
includes alkyldimethylbenzyl ammonium chlorides.
by but not covered with agar, inoculated, and incubated.
1.2 Conclusions about mold growth resistance are drawn
3.2 After various incubation periods, mold growth is rated
from the results by comparing the test with a simultaneously
run control of known resistance. Success or failure is deter- asapercentageoftheWetBlueandWetWhitesurfacecovered
by mold.
mined by the amount of mold growth relative to the control.
1.3 To allow use of this test method by any laboratory, 3.3 ResistancetomoldgrowthoftheWetBlueorWetWhite
test specimen is determined by comparison with Wet Blue or
flexibility has been permitted in times, temperature, and
humidity of incubation, inoculum, hide sampling area, and Wet White of known resistance characteristics (the control),
that is tested simultaneously.
choiceofcontrol.Thesemaybeadjustedtofitlocalconditions
but must be standardized.
4. Significance and Use
1.4 The values stated in SI units are to be regarded as
4.1 This test method provides a technique for evaluating
standard. No other units of measurement are included in this
mold growth resistance characteristics of Wet Blue and Wet
standard.
White, and should assist in the prediction of storage time
1.5 This standard does not purport to address all of the
before molding occurs.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 4.2 Thedegreeofcorrelationbetweenthistestandcommer-
priate safety, health, and environmental practices and deter-
cial quantities of Wet Blue and Wet White in storage or
mine the applicability of regulatory limitations prior to use. shipment situations, or both, has not been fully determined.
1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard- 5. Interferences
ization established in the Decision on Principles for the
5.1 Acommon interference is contamination of plates, agar,
Development of International Standards, Guides and Recom-
or samples by unwanted organisms that settle in from the
mendations issued by the World Trade Organization Technical
environment.
Barriers to Trade (TBT) Committee.
5.2 Volatility and Leachability of Biocides—A “zone of
inhibition” where no mold grows on the agar adjacent to the
2. Terminology
specimen indicates that the fungicide may leach.
2.1 Definitions of Terms Specific to This Standard:
2.1.1 Wet Blue—hide or skin, or split of a hide or skin,
6. Apparatus
tanned with basic chromium sulfate, containing approximately
6.1 Petri Dishes, 120 mm diameter. Sterile plastic dispos-
50% moisture and having an acidic pH.
able dishes are preferred.
6.2 Incubator, or location providing similar conditions be-
1 ing free of drafts, and capable of a constant (62 °C) tempera-
ThistestmethodisunderthejurisdictionofASTMCommitteeD31onLeather
and is the direct responsibility of Subcommittee D31.02 on Wet Blue. ture within the 26 to 30 °C range.
Current edition approved Sept. 1, 2021. Published October 2021. Originally
6.3 Medicine droppers,disposableplastictypedelivering30
approved in 1986. Last previous edition approved in 2016 as D4576-16. DOI:
10.1520/D4576-16R21. to 35 drops per mL.
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D4576 − 16 (2021)
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7. Reagents and Materials 9.3.1 Reduce working stock of 1×10 spores per mL to
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2 1×10 by diluting 1 volume to 10 volumes with water.
7.1 Potato Dextrose Agar, a dehydrated plating
...