ASTM C225-85(2022)
(Test Method)Standard Test Methods for Resistance of Glass Containers to Chemical Attack
Standard Test Methods for Resistance of Glass Containers to Chemical Attack
SIGNIFICANCE AND USE
3.1 The solubility of glass in contact with food, beverages, or pharmaceutical products is an important consideration for the safe packaging and storage of such materials. Autoclave conditions are specified since sterilization is often employed for the packaging of the product. It also represents one of the most extreme conditions, particularly of temperature, that containers will ordinarily experience. Any of the three test methods described may be used to establish specifications for conformity to standard values, either as specified by a customer, an agency, or “The United States Pharmacopeia:”
3.1.1 Test Method B-A is intended particularly for testing glass containers primarily destined for containment of products with a pH under 5.
3.1.2 Test Method B-W is intended particularly for testing glass containers to be used for products with a pH of 5.0 or over.
3.1.3 Test Method P-W is a hydrolytic autoclave test primarily intended for evaluating samples from untreated glass containers. It is often useful for testing the resistance of containers of too small capacity to permit measurements of solubility on the unbroken article by the B-W test method. Yielding the water resistance of the bulk glass, it can also be used in conjunction with the B-W test method to distinguish whether the internal surface of a container has been treated to improve its durability.
3.2 All three test methods are suitable for specification acceptance.
SCOPE
1.1 These test methods cover the evaluation of the resistance of glass containers to chemical attack. Three test methods are presented, as follows:
1.1.1 Test Method B-A covers autoclave tests at 121 °C on bottles partially filled with dilute acid as the attacking medium.
1.1.2 Test Method B-W covers autoclave tests at 121 °C on bottles partially filled with distilled water as the attacking medium.
1.1.3 Test Method P-W covers autoclave tests at 121 °C on powdered samples with pure water as the attacking medium.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
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
Relations
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: C225 − 85 (Reapproved 2022)
Standard Test Methods for
Resistance of Glass Containers to Chemical Attack
This standard is issued under the fixed designation C225; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope D1125 Test Methods for Electrical Conductivity and Resis-
tivity of Water
1.1 These test methods cover the evaluation of the resis-
D1193 Specification for Reagent Water
tanceofglasscontainerstochemicalattack.Threetestmethods
E11 Specification for Woven Wire Test Sieve Cloth and Test
are presented, as follows:
Sieves
1.1.1 Test Method B-A covers autoclave tests at 121 °C on
E691 Practice for Conducting an Interlaboratory Study to
bottles partially filled with dilute acid as the attacking medium.
Determine the Precision of a Test Method
1.1.2 Test Method B-W covers autoclave tests at 121 °C on
bottles partially filled with distilled water as the attacking
3. Significance and Use
medium.
1.1.3 Test Method P-W covers autoclave tests at 121 °C on 3.1 The solubility of glass in contact with food, beverages,
powdered samples with pure water as the attacking medium. or pharmaceutical products is an important consideration for
the safe packaging and storage of such materials. Autoclave
1.2 The values stated in SI units are to be regarded as the
conditions are specified since sterilization is often employed
standard. The values in parentheses are for information only.
for the packaging of the product. It also represents one of the
1.3 This standard does not purport to address all of the
most extreme conditions, particularly of temperature, that
safety concerns, if any, associated with its use. It is the
containers will ordinarily experience. Any of the three test
responsibility of the user of this standard to establish appro-
methods described may be used to establish specifications for
priate safety, health, and environmental practices and deter-
conformity to standard values, either as specified by a
mine the applicability of regulatory limitations prior to use.
customer, an agency, or “The United States Pharmacopeia:”
1.4 This international standard was developed in accor-
3.1.1 Test Method B-A is intended particularly for testing
dance with internationally recognized principles on standard-
glasscontainersprimarilydestinedforcontainmentofproducts
ization established in the Decision on Principles for the
with a pH under 5.
Development of International Standards, Guides and Recom-
3.1.2 Test Method B-W is intended particularly for testing
mendations issued by the World Trade Organization Technical
glass containers to be used for products with a pH of 5.0 or
Barriers to Trade (TBT) Committee.
over.
3.1.3 Test Method P-W is a hydrolytic autoclave test primar-
2. Referenced Documents
ily intended for evaluating samples from untreated glass
2.1 ASTM Standards:
containers. It is often useful for testing the resistance of
A569/A569M Specification for Steel, Carbon (0.15
containers of too small capacity to permit measurements of
Maximum,Percent),Hot-RolledSheetandStripCommer-
solubility on the unbroken article by the B-W test method.
cial
Yielding the water resistance of the bulk glass, it can also be
used in conjunction with the B-W test method to distinguish
whether the internal surface of a container has been treated to
improve its durability.
These test methods are under the jurisdiction of ASTM Committee C14 on
Glass and Glass Products and are the direct responsibility of Subcommittee C14.02
3.2 All three test methods are suitable for specification
on Chemical Properties and Analysis.
acceptance.
Current edition approved July 1, 2022. Published July 2022. Originally approved
in 1949. Last previous edition approved 2014 as C225 – 85 (2014). DOI: 10.1520/
C0225-85R22.
4. Purity of Reagents
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4.1 Reagent grade chemicals shall be used in all tests.
Standards volume information, refer to the standard’s Document Summary page on
Unless otherwise indicated, it is intended that all reagents shall
the ASTM website.
conform to the specifications of the Committee on Analytical
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org. Reagents of the American Chemical Society, where such
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C225 − 85 (2022)
specifications are available. Other grades may be used, pro- phthalein indicator solution and titrate with the NaOH solution
vided it is first ascertained that the reagent is of sufficiently to the first persistent pink color. Adjust the standard NaOH
high purity to permit its use without lessening the accuracy of
solution to 0.020N strength.
the determination.
6.4.1 Calculate the normality N of the NaOH solution as
follows:
4.2 Unless otherwise indicated, references to water shall be
understood to mean distilled water or other water meeting the
N 5 0.9798/mL of NaOH (1)
requirements for one of the types of reagent water covered by
6.5 High-Purity Water—This water shall be free of heavy
Specification D1193.
metals, particularly copper, as shown by a dithizone test and
TEST METHOD B-A—RESISTANCE OF BOTTLES
have a conductivity (consult Test Methods D1125) not exceed-
TO ATTACK BY DILUTE ACID
ing 0.15 µS/cm.
6.5.1 The source water shall be distilled, then passed
5. Apparatus
through a deionizer cartridge packed with a mixed bed of
5.1 Autoclave or Steam Sterilizer, capable of withstanding a
nuclear-grade resin, then through a cellulose ester membrane
pressure of 165 kPa (24 psi) and, preferably, equipped with a
having openings not exceeding 0.45 µm. Pass the purified
constant-pressure regulator or other means for maintaining the
water through an in-line conductivity cell to verify its purity.
temperature at 121 °C 6 0.5 °C (250 °F 6 0.9 °F). This
After flushing discharge lines, suitable water should be dis-
temperature shall be checked by means of a suitably calibrated
pensed directly into the test vessels.
instrument. The autoclave shall be capable of accommodating
at least six and preferably twelve of the largest containers to be
NOTE 1—Copper tubing should not be used in the discharge lines.
TFE-fluorocarbon or pure tin are suitable.
tested. It shall be equipped with a rack for supporting the
NOTE 2—Reference should be made to Specification D1193. Type I
samples, a thermometer, a pressure gauge, and a vent cock.
reagent water as defined therein complies with the present 6.5.Inthe
interest of practicality and demonstrated sufficiency, 6.5 allows the
6. Reagents and Materials
following deviations from Type I reagent water specifications.
6.1 Acetone, USP grade.
(1) Source water is unspecified whereas Type I specifies source water
having a maximum conductivity of 20 µS/cm at 25 °C.
6.2 Methyl Red Indicator Solution—Dissolve 24 mg of the
(2) The final step is filtration through a membrane having openings not
sodium salt of methyl red in 100 mL of water. If necessary,
exceeding 0.45 µm. Type I directs filtration through a 0.2 µm membrane.
neutralizetheindicatorsolutionwith0.020Nsodiumhydroxide
(3) The conductivity immediately before dispensing is required not to
(NaOH) solution so that the titer of five drops of the indicator
exceed 0.15 µS/cm at 25 °C whereas Type I is limited to 0.06 µS/cm at
solution in 100 mL of the special distilled water does not 25 °C.
The distillation step is essential to minimize or avoid cultivation of
exceed 0.02 mL of 0.020N NaOH solution. In titrations using
microorganisms in the ion-exchange bed and consequent clogging of the
the methyl red indicator solution, the end point shall be taken
membrane filter. When preceded by distillation, the ion-exchange bed
at a pH of 5.6.
should have a long life, but as the conductivity begins to rise toward the
limit it should be replaced by a new bed.
6.3 Phenolphthalein Indicator Solution—Dissolve 0.5 g of
Distillation from phosphoric acid with a conductivity of the product
phenolphthalein in 60 mL of ethyl alcohol (95 %) and dilute
between 0.5 µS⁄cm and 1.0 µS/cm was specified as water for extraction in
with water to 100 mL.
Test Methods C225. Water prepared as described herein gave results
averaging about 8 % higher than water prepared by distillation from
6.4 Sodium Hydroxide Solution, Standard (0.020N)—
phosphoric acid when Test Method B-W was applied to soda-lime and
Dissolve 100 g of NaOH in 100 mL of water in a 150 mL test
borosilicate glass bottles in seven laboratories. The trend to slightly
tube. Avoid wetting the top of the test tube. Stopper the tube
greater extraction may be associated with the higher average purity of this
loosely with a stopper covered with tinfoil and allow to stand
water. The limit on conductivity of 0.15 µS/cm for water prepared by this
in a vertical position until the supernatant liquid is clear.
means was set because water of less conductivity is readily obtained and
Withdraw some of the clear solution in a measuring pipet and when0.15µS/cmisexceeded,theconductivityrisesrapidlyonfurtheruse
of the system.
deliver 1.3 mL into a paraffin-lined bottle containing 1 L of
carbon dioxide (CO )-free water. Stopper the bottle with a
6.6 Sulfuric Acid, Standard (0.020N) containing approxi-
two-hole stopper carrying a glass siphon tube (for delivering
mately 0.58 mL of concentrated sulfuric acid (H SO,spgr
2 4
the solution to a buret) and a soda-lime or soda-asbestos guard
1.84) in 1 L of solution. Prepare 0.1N H SO containing
2 4
tube. Standardize the 0.020N NaOH solution against the
3.0 mL of concentrated sulfuric acid (H SO , sp gr 1.84)/L.
2 4
National Institute of Standards and Technology Standard
Dilute 200 mL of the 0.1N H SO to 1 L and standardize
2 4
Sample No. 84h of acid potassium phthalate.Transfer 0.2000 g
against 0.020N NaOH solution, using methyl red indicator
of the phthalate to a 250 mL Erlenmeyer flask and dissolve in
solution.Finally,adjustthestandardH SO to0.020Nstrength.
2 4
about 75 mL of CO -free water. Add five drops of phenol-
6.7 Sulfuric Acid, Standard (0.0005N)—Mix 1 volume of
0.1N H SO with 199 volumes of water.Adjust the strength to
2 4
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
be 0.0005 6 0.000025N.
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
6.8 Sulfuric Acid, Standard (0.0002N)—Mix 1 volume of
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
0.1N H SO with 499 volumes of water.Adjust the strength to
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma- 2 4
copeial Convention, Inc. (USPC), Rockville, MD. be 0.0002 6 0.00001N.
C225 − 85 (2022)
7. Preparation of Sample TEST METHOD B-W—RESISTANCE OF BOTTLES
TO ATTACK BY WATER
7.1 If the bottles are 168 cm (6 oz) capacity or over, select
threebottles.Ifthebottlesaresmallerthan6 ozcapacity,select
10. Apparatus
a sufficient number so the contents can be combined to form
10.1 See Section 5.
three sets to give 100 mL/set. Rinse each container with two
portions of the high-purity water, follow with two similar
11. Reagents
rinsings using acetone and dry with a stream of clean dry air.
11.1 See 6.2 – 6.6.
8. Procedure
12. Preparation of Sample
8.1 Fill the containers, at room temperature, to 90 % of
12.1 Ifthebottlesare168 cm (6 oz)capacityorover,select
overflow capacity with the attacking medium.
three bottles. If the bottles are smaller than 168 cm capacity,
select a sufficient number so that the contents can be combined
NOTE 3—If the bottles to be tested will neutralize more than the
equivalent of 0.80 mL of 0.020N H SO , use 0.0005N H SO as the to form three sets to give 100 mL/set. Rinse each container
2 4 2 4
attacking medium. Otherwise, use 0.0002N H SO as the attacking
with two portions of the high-purity water as described in 6.5.
2 4
medium.
13. Procedure
8.2 Cover each container individually with a chemical-
resistant glass beaker or cap that has been digested with water
13.1 Fill the containers, at room temperature, to 90 % of
for at least 24 h at 90 °C (194 °F) or1hat121°C (250 °F). overflow capacity with the high-purity water. Continue as
These covers shall be of such size that the bottoms of the described in 8.2.
beakers or caps fit snugly down on the top rims of the
13.2 Titration of Bottle Extract—Using a graduated
containers. Place the containers on the rack in the autoclave.
cylinder, transfer 100 mLportions of the test solution from the
The sample rack must support the samples above water level.
containers to 250 mL flasks of chemical-resistant glass. Add
Closethecoversecurely,leavingtheventcockopen.Heatuntil
five drops of methyl red indicator solution to each flask and
steam issues vigorously from the vent. Allow steam to issue
titratewith0.020NH SO (Note4).Thetimeelapsingbetween
2 4
from the vent for 10 min; then close the vent cock and increase
opening the autoclave and titrating the solution should not
the temperature at the rate of 1 °C⁄min to 121 °C taking 19 to
exceed 1 h.
23 min. Maintain the temperature at 121 °C 6 0.5 °C (250 °F
13.3 Blank—Titrate 100 mL of the high-purity water at the
6 0.9 °F) for 1 h, counting from the time when the holding
same temperature and using the same amount of indicator as in
temperature is reached. At the end of the hour, cool at the rate
titration of the bottle extract in accordance with 13.2.
of 0.5 °C⁄min to atmospheric pressure, venting to prevent
formation of a vacuum. The time to cool from 121 °C to
14. Calculation and Report
atmospheric pressure should be from 38 to 46 min. Open the
14.1 Report the results as millilitres of 0.020N H SO
2 4
autoclave and remove the containers.
required for titration of the sample, minus millilitres required
for titration of the blank.
8.3 Titration of Bottle Extract—Cool the containers and
contents to room temperature. With a pipet, transfer 100 mL
TEST METHOD P-W—RESISTANCE
portions of the test solution from the containers to 250 mL
OF POWDERED SAMPLE TO ATTACK BY WATER
flasks of chemical-resistant glass.Add
...
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