1、Designation: C225 85 (Reapproved 2009)Standard Test Methods forResistance of Glass Containers to Chemical Attack1This standard is issued under the fixed designation C225; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the evaluati
3、on of the resis-tance of glass containers to chemical attack. Three test methodsare presented, as follows:1.1.1 Test Method B-A covers autoclave tests at 121C onbottles partially filled with dilute acid as the attacking medium.1.1.2 Test Method B-W covers autoclave tests at 121C onbottles partially
4、filled with distilled water as the attackingmedium.1.1.3 Test Method P-W covers autoclave tests at 121C onpowdered samples with pure water as the attacking medium.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 This standard
5、 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM
6、Standards:2A569/A569M Specification for Steel, Carbon (0.15 Maxi-mum, Percent), Hot-Rolled Sheet and Strip Commercial3D1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterD1193 Specification for Reagent WaterE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE691 Prac
7、tice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Significance and Use3.1 The solubility of glass in contact with food, beverages,or pharmaceutical products is an important consideration forthe safe packaging and storage of such materials. Autoclaveconditions
8、are specified since sterilization is often employedfor the packaging of the product. It also represents one of themost extreme conditions, particularly of temperature, thatcontainers will ordinarily experience. Any of the three testmethods described may be used to establish specifications forconform
9、ity to standard values, either as specified by a cus-tomer, an agency, or “The United States Pharmacopeia:”3.1.1 Test Method B-A is intended particularly for testingglass containers primarily destined for containment of productswith a pH under 5.3.1.2 Test Method B-W is intended particularly for tes
10、tingglass containers to be used for products with a pH of 5.0 orover.3.1.3 Test Method P-W is a hydrolytic autoclave test prima-rily intended for evaluating samples from untreated glasscontainers. It is often useful for testing the resistance ofcontainers of too small capacity to permit measurements
11、 ofsolubility on the unbroken article by the B-W test method.Yielding the water resistance of the bulk glass, it can also beused in conjunction with the B-W test method to distinguishwhether the internal surface of a container has been treated toimprove its durability.1These test methods are under t
12、he jurisdiction of ASTM Committee C14 onGlass and Glass Products and are the direct responsibility of Subcommittee C14.02on Chemical Properties and Analysis.Current edition approved Nov. 1, 2009. Published January 2010. Originallyapproved in 1949. Last previous edition approved 2004 as C225 85 (2004
13、). DOI:10.1520/C0225-85R09.2For 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 standards Document Summary page onthe ASTM website.3Withdrawn. The last approved vers
14、ion of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 All three test methods are suitable for specificationacceptance.4. Purity of Reagents4.1 Reagent grade chemicals shall b
15、e used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the re
16、agent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.4.2 Unless otherwise indicated, references to water shall beunderstood to mean distilled water or other water meeting therequirements for one of the types of reagent water covered bySpecification
17、 D1193.TEST METHOD B-ARESISTANCE OF BOTTLESTO ATTACK BY DILUTE ACID5. Apparatus5.1 Autoclave or Steam Sterilizer, capable of withstanding apressure of 165 kPa (24 psi) and, preferably, equipped with aconstant-pressure regulator or other means for maintaining thetemperature at 121 6 0.5C (250 6 0.9F)
18、. This temperatureshall be checked by means of a suitably calibrated instrument.The autoclave shall be capable of accommodating at least sixand preferably twelve of the largest containers to be tested. Itshall be equipped with a rack for supporting the samples, athermometer, a pressure gage, and a v
19、ent cock.6. Reagents and Materials6.1 Acetone, USP grade.6.2 Methyl Red Indicator SolutionDissolve 24 mg of thesodium salt of methyl red in 100 mL of water. If necessary,neutralize the indicator solution with 0.020N sodium hydroxide(NaOH) solution so that the titer of five drops of the indicatorsolu
20、tion in 100 mL of the special distilled water does notexceed 0.02 mL of 0.020N NaOH solution. In titrations usingthe methyl red indicator solution, the end point shall be takenat a pH of 5.6.6.3 Phenolphthalein Indicator SolutionDissolve 0.5 g ofphenolphthalein in 60 mL of ethyl alcohol (95 %) and d
21、ilutewith water to 100 mL.6.4 Sodium Hydroxide Solution, Standard (0.020N)Dissolve 100 g of NaOH in 100 mL of water in a 150-mL testtube. Avoid wetting the top of the test tube. Stopper the tubeloosely with a stopper covered with tinfoil and allow to standin a vertical position until the supernatant
22、 liquid is clear.Withdraw some of the clear solution in a measuring pipet anddeliver 1.3 mL into a paraffin-lined bottle containing 1 L ofcarbon dioxide (CO2)-free water. Stopper the bottle with atwo-hole stopper carrying a glass siphon tube (for deliveringthe solution to a buret) and a soda-lime or
23、 soda-asbestos guardtube. Standardize the 0.020N NaOH solution against theNational Institute of Standards and Technology StandardSample No. 84h of acid potassium phthalate. Transfer 0.2000 gof the phthalate to a 250-mL Erlenmeyer flask and dissolve inabout 75 mL of CO2-free water. Add five drops of
24、phenol-phthalein indicator solution and titrate with the NaOH solutionto the first persistent pink color. Adjust the standard NaOHsolution to 0.020N strength.6.4.1 Calculate the normality N of the NaOH solution asfollows:N 5 0.9798/mL of NaOH (1)6.5 High-Purity WaterThis water shall be free of heavy
25、metals, particularly copper, as shown by a dithizone test andhave a conductivity (consult Test Methods D1125) not exceed-ing 0.15 S/cm.6.5.1 The source water shall be distilled, then passedthrough a deionizer cartridge packed with a mixed bed ofnuclear-grade resin, then through a cellulose ester mem
26、branehaving openings not exceeding 0.45 m. Pass the purifiedwater through an in-line conductivity cell to verify its purity.After flushing discharge lines, suitable water should be dis-pensed directly into the test vessels.NOTE 1Copper tubing should not be used in the discharge lines.TFE-fluorocarbo
27、n or pure tin are suitable.NOTE 2Reference should be made to Specification D1193. Type Ireagent water as defined therein complies with the present 6.5.Intheinterest of practicality and demonstrated sufficiency, 6.5 allows thefollowing deviations from Type I reagent water specifications.(1) Source wa
28、ter is unspecified whereas Type I specifies source waterhaving a maximum conductivity of 20 S/cm at 25C.(2) The final step is filtration through a membrane having openings notexceeding 0.45 m. Type I directs filtration through a 0.2-m membrane.(3) The conductivity immediately before dispensing is re
29、quired not toexceed 0.15 S/cm at 25C whereas Type I is limited to 0.06 S/cm at25C.The distillation step is essential to minimize or avoid cultivation ofmicroorganisms in the ion-exchange bed and consequent clogging of themembrane filter. When preceded by distillation, the ion-exchange bedshould have
30、 a long life, but as the conductivity begins to rise toward thelimit it should be replaced by a new bed.Distillation from phosphoric acid with a conductivity of the productbetween 0.5 and 1.0 S/cm was specified as water for extraction in TestMethods C225. Water prepared as described herein gave resu
31、lts averagingabout 8 % higher than water prepared by distillation from phosphoric acidwhen Test Method B-W was applied to soda-lime and borosilicate glassbottles in seven laboratories. The trend to slightly greater extraction maybe associated with the higher average purity of this water. The limit o
32、nconductivity of 0.15 S/cm for water prepared by this means was setbecause water of less conductivity is readily obtained and when 0.15S/cm is exceeded, the conductivity rises rapidly on further use of thesystem.6.6 Sulfuric Acid, Standard (0.020N) containing approxi-mately 0.58 mL of concentrated s
33、ulfuric acid (H2SO4,spgr1.84) in 1 L of solution. Prepare 0.1N H2SO4containing 3.0mL of concentrated sulfuric acid (H2SO4, sp gr 1.84)/L. Dilute200 mL of the 0.1N H2SO4to 1 L and standardize against0.020N NaOH solution, using methyl red indicator solution.Finally, adjust the standard H2SO4to 0.020N
34、strength.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States P
35、harmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.C225 85 (2009)26.7 Sulfuric Acid, Standard (0.0005N)Mix 1 volume of0.1N H2SO4with 199 volumes of water. Adjust the strength tobe 0.0005 6 0.000025N.6.8 Sulfuric Acid, Standard (0.0002N)Mix 1 volume of0.1N H2S
36、O4with 499 volumes of water. Adjust the strength tobe 0.0002 6 0.00001N.7. Preparation of Sample7.1 If the bottles are 168cm3(6-oz) capacity or over, selectthree bottles. If the bottles are smaller than 6-oz capacity, selecta sufficient number so the contents can be combined to formthree sets to giv
37、e 100 mL/set. Rinse each container with twoportions of the high-purity water, follow with two similarrinsings using acetone and dry with a stream of clean dry air.8. Procedure8.1 Fill the containers, at room temperature, to 90 % ofoverflow capacity with the attacking medium.NOTE 3If the bottles to b
38、e tested will neutralize more than theequivalent of 0.80 mL of 0.020N H2SO4, use 0.0005N H2SO4as theattacking medium. Otherwise, use 0.0002N H2SO4as the attackingmedium.8.2 Cover each container individually with a chemical-resistant glass beaker or cap that has been digested with waterfor at least 2
39、4 h at 90C (194F) or1hat121C (250F). Thesecovers shall be of such size that the bottoms of the beakers orcaps fit snugly down on the top rims of the containers. Placethe containers on the rack in the autoclave. The sample rackmust support the samples above water level. Close the coversecurely, leavi
40、ng the vent cock open. Heat until steam issuesvigorously from the vent. Allow steam to issue from the ventfor 10 min; then close the vent cock and increase thetemperature at the rate of 1C/min to 121C taking 19 to 23min. Maintain the temperature at 121 6 0.5C (250 6 0.9F)for 1 h, counting from the t
41、ime when the holding temperatureis reached. At the end of the hour, cool at the rate of 0.5C/minto atmospheric pressure, venting to prevent formation of avacuum. The time to cool from 121C to atmospheric pressureshould be from 38 to 46 min. Open the autoclave and removethe containers.8.3 Titration o
42、f Bottle ExtractCool the containers andcontents to room temperature. With a pipet, transfer 100-mLportions of the test solution from the containers to 250-mLflasks of chemical-resistant glass. Add five drops of methyl redindicator solution to each flask and titrate with 0.20N NaOHsolution.NOTE 4When
43、 titrations are under 1 mL, a microburet should be used.9. Calculation and Report9.1 Report the results as millilitres of 0.020N acid con-sumed in the test, A. Calculate as follows:A 5 V 2 0.98B (2)where:V = 0.020N NaOH solution equivalent to 100 mL of theattacking medium, mL;B = 0.020N NaOH solutio
44、n used in the titration of 100mL of bottle extract, mL; and0.98 = factor applied to the titration of the bottle extract tocorrect that titration for loss of attacking mediumduring cooling of the autoclave.TEST METHOD B-WRESISTANCE OF BOTTLESTO ATTACK BY WATER10. Apparatus10.1 See Section 5.11. Reage
45、nts11.1 See 6.2-6.6.12. Preparation of Sample12.1 If the bottles are 168-cm3(6-oz) capacity or over,select three bottles. If the bottles are smaller than 168cm3capacity, select a sufficient number so that the contents can becombined to form three sets to give 100 mL/set. Rinse eachcontainer with two
46、 portions of the high-purity water asdescribed in 6.5.13. Procedure13.1 Fill the containers, at room temperature, to 90 % ofoverflow capacity with the high-purity water. Continue asdescribed in 8.2.13.2 Titration of Bottle ExtractUsing a graduated cylin-der, transfer 100-mL portions of the test solu
47、tion from thecontainers to 250-mL flasks of chemical-resistant glass. Addfive drops of methyl red indicator solution to each flask andtitrate with 0.020N H2SO4(Note 4). The time elapsing betweenopening the autoclave and titrating the solution should notexceed 1 h.13.3 BlankTitrate 100 mL of the high
48、-purity water at thesame temperature and using the same amount of indicator as intitration of the bottle extract in accordance with 13.2.14. Calculation and Report14.1 Report the results as millilitres of 0.020N H2SO4required for titration of the sample, minus millilitres requiredfor titration of th
49、e blank.TEST METHOD P-WRESISTANCE OFPOWDERED SAMPLE TO ATTACK BY WATER15. Apparatus15.1 AutoclaveSee 5.1.15.2 FlasksErlenmeyer flasks of 250-mL capacity, madeof chemical-resistant glass and suitably aged by previoustreatment similar to the test or by previous use.15.3 Crushing DeviceEither a special steel mortar or aspecial steel jar mill may be used as alternative means ofpreparing a crushed sample of glass.15.3.1 MortarA hardened steel mortar of special designmade in accordance with Fig. 1, and a hammer weighing about0.9 kg (2 lbs)
