The following tests are designed to determine the resistance to water attack of new (not previously used)glass containers.The degree of attack is determined by the amount of alkali released from the glass under the influence of the attacking medium under the conditions specified.This quantity of alkali is extremely small in the case of the more resistant glasses,thus calling for particular attention to all details of the tests and the use of apparatus of high quality and precision.The tests should be conducted in an area relatively free from fumes and excessive dust.

Type	General Description1	Type of Test	Limits
			Size,2 mL	mLof 0.020 N Acid
I	Highly resistant, borosilicate glass	Powdered Glass	All	1.0
II	Treated soda-lime glass	Water Attack	100or less	0.7
			Over 100	0.2
III	Soda-lime glass	Powdered Glass	All	8.5
NP	General-purpose soda-lime glass	Powdered Glass	All	15.0
1  The description applies to containers of this type of glass usually available. 2  Size indicates the overflow capacity of the container.

Autoclave— For these tests,use an autoclave capable of maintaining a temperature of 121±2.0,equipped with a thermometer,a pressure gauge,a vent cock,and a rack adequate to accommodate at least 12test containers above the water level.

Mortar and Pestle— Use a hardened-steel mortar and pestle,made according to the specifications in the accompanying illustration.

Other Equipment— Also required are 20.3-cm (8-inch)sieves made of stainless steel including the Nos.20,40,and 50sieves along with the pan and cover (see Sizes of Standard Sieve Series in Range of Interestunder Particle Size Distribution Estimation by Analytical Sieving á786ñ),250-mLconical flasks made of resistant glass aged as specified,a 900-g (2-lb)hammer,a permanent magnet,a desiccator,and an adequate volumetric apparatus.

High-Purity Water— The water used in these tests has a conductivity at 25,as measured in an in-line cell just prior to dispensing,of not greater than 0.15µSper cm (6.67Megohm-cm).There must also be an assurance that this water is not contaminated by copper or its products (e.g.,copper pipes,stills,or receivers).The water may be prepared by passing distilled water through a deionizer cartridge packed with a mixed bed of nuclear-grade resin,then through a cellulose ester membrane having openings not exceeding 0.45µm.3Do not use copper tubing.Flush the discharge lines before water is dispensed into test vessels.When the low conductivity specification can no longer be met,replace the deionizer cartridge.

Methyl Red Solution— Dissolve 24mg of methyl red sodium in Purified Waterto make 100mL.If necessary,neutralize the solution with 0.02Nsodium hydroxide or acidify it with 0.02Nsulfuric acid so that the titration of 100mLof High-Purity Water,containing 5drops of indicator,does not require more than 0.020mLof 0.020Nsodium hydroxide to effect the color change of the indicator,which should occur at a pHof 5.6.

Powdered Glass Test

Procedure— Transfer 10.00g of the prepared specimen,accurately weighed,to a 250-mLconical flask that has been digested (aged)previously with High-Purity Waterin a bath at 90for at least 24hours or at 121for 1hour.Add 50.0mLof High-Purity Waterto this flask and to one similarly prepared to provide a blank.Cap all flasks with borosilicate glass beakers that previously have been treated as described for the flasks and that are of such size that the bottoms of the beakers fit snugly down on the top rims of the containers.Place the containers in the autoclave,and close it securely,leaving the vent cock open.Heat until steam issues vigorously from the vent cock,and continue heating for 10minutes.Close the vent cock,and adjust the temperature to 121,taking 19to 23minutes to reach the desired temperature.Hold the temperature at 121±2.0for 30minutes,counting from the time this temperature is reached.Reduce the heat so that the autoclave cools and comes to atmospheric pressure in 38to 46minutes,being vented as necessary to prevent the formation of a vacuum.Cool the flask at once in running water,decant the water from the flask into a suitably cleansed vessel,and wash the residual powdered glass with four 15-mLportions of High-Purity Water,adding the decanted washings to the main portion.Add 5drops of Methyl Red Solution,and titrate immediately with 0.020Nsulfuric acid.If the volume of titrating solution is expected to be less than 10mL,use a microburet.Record the volume of 0.020Nsulfuric acid used to neutralize the extract from 10g of the prepared specimen of glass,corrected for a blank.The volume does not exceed that indicated in Table 2for the type of glass concerned.

Water Attack at 121

Procedure— Fill each container to 90%of its overflow capacity with High-Purity Water,and proceed as directed for Procedureunder Powdered Glass Test,beginning with “Cap all flasks,”except that the time of autoclaving shall be 60minutes instead of 30minutes,and ending with “to prevent the formation of a vacuum.”Empty the contents from 1or more containers into a 100-mLgraduated cylinder,combining,in the case of smaller containers,the contents of several containers to obtain a volume of 100mL.Place the pooled specimen in a 250-mLconical flask of resistant glass,add 5drops of Methyl Red Solution,and titrate,while warm,with 0.020Nsulfuric acid.Complete the titration within 60minutes after opening the autoclave.Record the volume of 0.020Nsulfuric acid used,corrected for a blank obtained by titrating 100mLof High-Purity Waterat the same temperature and with the same amount of indicator.The volume does not exceed that indicated in Table 2for the type of glass concerned.

Arsenic

Arsenic á211ñ— Use as the Test Preparation35mLof the water from one Type Iglass container or,in the case of smaller containers,35mLof the combined contents of several Type Iglass containers,prepared as directed for Procedureunder Water Attack at 121:the limit is 0.1µg per g.