ASTM D8196-18
(Practice)Standard Practice for Determination of Water Activity (aw) in Cannabis Flower
Standard Practice for Determination of Water Activity (<emph type="ital">a<inf>w</inf ></emph>) in Cannabis Flower
SIGNIFICANCE AND USE
5.1 This practice is designed for use on cannabis flower by cannabis producers, processors, dispensers, testing laboratories, and end users. aw testing at any point in the supply chain is an important element in ensuring the safety and quality of cannabis flower. Testing can occur spontaneously at any point in the supply chain by regulatory agencies, suppliers, and customers.
5.2 This practice is an important endpoint in determining whether a cannabis flower sample is being stored under optimal storage conditions (see Specification D8197).
5.3 Analysis of water activity should be considered an important quality control step in ensuring a cannabis flower sample is being stored under optimal storage conditions to prevent mold and/or other microbiological growth and/or breakage.
5.4 Maintaining the requisite aw throughout the supply chain from completion of drying through merchandising ensures safety and quality for the consumer.
5.5 Water activity is used in many cases as a critical control point for Hazard Analysis and Critical Control Points (HACCP) programs. Controlling aw should not be seen as a kill step.7 Rather control of aw focuses on preventing the growth and proliferation of microorganisms.
5.6 This practice is designed for use by trained technical individuals with minimal knowledge of complex analytical chemistry procedures.
SCOPE
1.1 This practice covers the recommended procedure for determining the water activity (aw) of a cannabis flower sample.
1.2 Units—The values stated in SI units are to be regarded as the standard. Water activity is a ratio, and thus is without unit designation.
1.3 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.
1.4 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
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D8196 − 18
Standard Practice for
1
Determination of Water Activity (a ) in Cannabis Flower
w
This standard is issued under the fixed designation D8196; 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
The concept of water activity is more than 50 years old. For many years, researchers tried to equate
bacterial growth potential with water content. William Jones Scott showed in 1953 that microorgan-
2
isms have a limiting a level for growth, thus being the first to establish that bacterial growth
w
correlated with water activity, not water content of organic materials. It is now generally accepted that
a is more closely related to the microbial, chemical, and physical properties of foods and other
w
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natural products than is total moisture. It is firmly established that growth of specific microbes is
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inhibited at or below specific water activity values.
Totalwatercontent(moisture)measurementsdonotnecessarilyreflectwateravailableformicrobial
growth and thus are an inaccurate means for controlling microbial growth, because the water content
sufficientformicrobialgrowthisdependentonthesubstancebeingtested.Wateractivitymeasurement
is more accurate than total water content (moisture) measurement as it relates directly to the water
available to microbes. Safe a levels are constant relative to particular microbes, regardless of the
w
substance being tested.
1. Scope Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This practice covers the recommended procedure for
Barriers to Trade (TBT) Committee.
determining the water activity (a ) of a cannabis flower
w
sample.
2. Referenced Documents
1.2 Units—The values stated in SI units are to be regarded 5
2.1 ASTM Standards:
as the standard. Water activity is a ratio, and thus is without
D8197 Specification for Maintaining Acceptable Water Ac-
unit designation.
tivity (a ) Range (0.55 to 0.65) for Dry Cannabis Flower
w
1.3 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1 Definitions of Terms Specific to This Standard:
priate safety, health, and environmental practices and deter-
3.1.1 cannabis flower, n—the flowering or fruiting tops of
mine the applicability of regulatory limitations prior to use.
the cannabis plant (excluding seeds and leaves when not
1.4 This international standard was developed in accor-
accompaniedbyfloweringorfruitingtop)fromwhichtheresin
dance with internationally recognized principles on standard-
has not been extracted. (adapted from the UN Single Conven-
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ization established in the Decision on Principles for the
tion on Narcotic Drugs, 1961 )
3.1.2 cultivator container, n—packaging used by cannabis
grower/harvestertostoreand/orshipproductinlargequantities
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This practice is under the jurisdiction of ASTM Committee D37 on Cannabis
after drying.
and is the direct responsibility of Subcommittee D37.04 on Processing and
Handling.
3.1.3 dispensary container, n—packaging used by a
Current edition approved May 15, 2018. Published May 2018. DOI: 10.1520/
cannabis-dispensing establishment to provide the cannabis
D8196-18.
2 flower consumer a satisfactory storage container.
Scott,W.J.,WaterrelationsofStaphylococcusaureusat30°. Australian Journal
of Biological Sciences6, 1953, pp 549-564.
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Chirife, J. and Fontana, A. J. (2007) Introduction: Historical Highlights of
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Water Activity Research, in Water Activity in Foods: Fundamentals and Applica- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
tions (eds G. V. Barbosa-Cánovas, A. J. Fontana, S. J. Schmidt and T. P. Labuza), contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Blackwell Publishing Ltd, Oxford, UK. doi: 10.1002/9780470376454.ch1 Standards volume information, refer to the standard’s Document Summary page on
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Russell, N.J., Leistner, L., and Gould, G.W. Solutes and Low WaterActivity in the ASTM website.
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Food Preservatives ed N.J. Russell and G.W. Gould, Springer 2012, pp119ff. www.unodc.org/pdf/convention_1961_en.pdf, p1, Accessed 2018.01.23
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D8196 − 18
3.1.4 packager container, n—packaging used by the pack- 7. Testing Facilities and Personnel
ager to store and ship product to dispensing establishments.
7.1 All testing shall be carried
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