1、Designation:D819721Standard Specification forMaintaining Acceptable Water Activity(aw)Range(0.55 to0.65)for Dry Cannabis Flower Intended for Human/AnimalUse1This standard is issued under the fixed designation D8197;the number immediately following the designation indicates the year oforiginal adopti
2、on or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe concept of water activity is more than 50 years old.For many years,researche
3、rs tried to equatebacterial growth potential with water content.William Jones Scott showed in 1953 that microorgan-isms have a limiting awlevel for growth(1),2thus being the first to establish that bacterial growthcorrelated with water activity,not water content of organic materials.It is now genera
4、lly accepted thatawis more closely related to the microbial,chemical,and physical properties of foods and othernatural products than is total moisture(2).It is firmly established that growth of specific microbes andmetabolism of microbe associated toxins are inhibited at or below specific water acti
5、vity values(3,4).Total water content(moisture)measurements do not necessarily reflect water available for microbialgrowth and thus are an inaccurate means for controlling microbial growth,because the water contentsufficient for microbial growth is dependent on the substance being tested.Water activi
6、ty measurementis more accurate than total water content measurement as it relates directly to the water available(inliquid form)to microbes and is constant relative to the particular microbe,regardless of the substancebeing tested.1.Scope1.1 This specification covers the recommended range of awsuita
7、ble for safe and efficacious storage of cannabis flowers orportions thereof.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices
8、and deter-mine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom
9、-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D8196 Practice for Determination of Water Activity(aw)inCannabis Flower3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 water activity,aw,nthe pa
10、rtial vapor pressure ofwater in a substance divided by the partial vapor pressure ofpure water at the same temperature which is calculated bydividing the partial vapor pressure of water in the substance(P)by the partial vapor pressure of pure water at the sametemperature(Po),that is,aw=P/(Po).This d
11、escribes quantita-tively the capability of the cannabis flower in a sealed containerto affect the humidity of the containers headspace air.4.Significance and Use4.1 This specification is designed for use on cannabis flowerby cannabis producers,processors,dispensers,testinglaboratories,and end users.
12、1This specification is under the jurisdiction of ASTM Committee D37 onCannabis and is the direct responsibility of Subcommittee D37.04 on Processing andHandling.Current edition approved Feb.15,2021.Published March 2021.Originallyapproved in 2018.Last previous edition approved in 2018 as D8197 18.DOI
13、:10.1520/D8197-21.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the stand
14、ards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision
15、on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.14.2 Analysis and control of water activity should be consid-ered an important quality control step in ensuring a cannabisflower sam
16、ple is being stored under optimal storage conditionsto prevent mold or other microbiological growth and breakage.4.3 All constituent testing,other than water activity inaccordance with Practice D8196,shall be carried out on thecannabis flower sample that has been equilibrated to thisspecification in accordance with 6.1 and 6.2.4.4 Maintaining the requisite awthroughout the supplychain from completion of drying through merchandising en-sures safety and quality for the consumer.4.5 Water activity(
