ASTM F1094-87(R2020) pdf free download

ASTM F1094-87(R2020) pdf free download.Standard Test Methods for Microbiological Monitoring of Water Used for Processing Electron and Microelectronic Devices by Direct Pressure Tap Sampling Valve and by the Presterilized Plastic Bag Method
4. Summary of Test Method
4.1 Test MethodA—Sample Tap—Direct Filtration—A sam- pling valve as or similar to that shown in Fig. 1 is installed in a pressurized line. The valve illustrated has a self closure and a male luer outlet fitting. This valve design minimized the chance of extraneous contamination. Any valve used for sampling should be constructed in a manner to reduce or prevent the retention of bacteria within its internal surfaces, and should be easily sanitized. The bacterial monitor is connected to either the luer outlet of the illustrated sampling valve, or in a suitable manner to an equivalent valve. The water sample is passed directly through the monitor, and the effluent volume is measured after this filtration. Test Methods F60 are then employed for bacteriological examination of the sample. 4.2 Test Method B—Presterilized Plastic Bag—The sam- pling valve is installed as in Test Method A, then flushed clean prior to taking the samples. The water sample is directly flowed into a presterilized, precalibrated plastic disposable bag. After sampling, the plastic bag is sealed and stored briefly prior to bacteriological analysis of the sample. The sample may be stored at room temperature if analyzed within 2 h, otherwise, it should be stored from 4 to to 10°C and analyzed within 6 h. 4.2.1 Sample analysis is conducted by either Test Methods F60 or Test Method F488 for bacterial content of the water.
5. Significance and Use
5.1 These test methods provide a field technique for the bacteriological analysis of electronic process waters. The sampling ofthese waters and subsequent bacteriological analy- sis may be critical to electronic product yields. Bacteria can be the prime source of harmful contamination which can signifi- cantly reduce the yield of satisfactory microelectronic device production. 5.2 The test methods described here may be used both to monitor the bacteriological quality of water used in microelec- tronic product processing, and to locate the source of bacterial contamination in a water purification system. 5.3 These test methods are simple field methods, combining sampling and bacteriological analysis techniques that do not require bacteriological laboratory facilities. 5.4 The test methods described employ culture techniques for bacteriological analysis. The user should be aware that such techniques cannot provide a complete count of the total viable bacteria present, since clumps and clusters of bacteria will appear as one single colony when cultured, and since some viable bacteria will not grow under the test conditions used. However, a meaningful comparative bacteria count will be achieved by this method ifthe culturing ofthe sample is always done at the same temperature, and for the same period of time. The temperature of incubation should always be at 28 6 2°C, and the period of incubation should be 48 h (or 72 h if time permits). The period of incubation and temperature should be the same for all comparative studies.
8. Procedure
8.1 Sampling: 8.1.1 Connect sampling valve to pressurized line as shown in Fig. 1. 8.1.2 With water system operating, open valve fully, flush for 60 s at fast flow rate, and close the valve. 8.1.3 Fill syringe with blunt nose No. 18 needle with 70 to 90 % isopropyl alcohol, (or 3 to 6 % semi-standard or reagent grade, hydrogen peroxide), and insert the 2-in. needle com- pletely into the sampling valve outlet port. 8.1.4 Inject 5 mL of the sanitizing agent chosen into the sampling port and allow to stand for 1 min. Remove the needle from the outlet port, and squirt some ofthe agent on the outside of the male luer connector. 8.1.5 Flush the valve again for 1 min and close the valve. 8.1.6 Remove inlet and outlet caps from a bacteriological monitor. Place caps aside on a clean surface, and avoid contaminating the inner surfaces. Connect the monitor to the male luer outlet of the sampling valve, as shown in Fig. 2. Avoid finger contacts of inlet and outlets of monitor. 8.1.7 Open sampling valve, by turning counter-clockwise the knurled outlet body, and allow 100 mL (Note 2) of sample to pass through the monitor into a volumetric container. Close the valve.