CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER d: LABORATORIES AND BLOOD BANKS
PART 465 CERTIFICATION AND OPERATION OF ENVIRONMENTAL LABORATORIES
SECTION 465.380 STANDARDS FOR LABORATORY PURE WATER
Section 465.380 Standards for Laboratory Pure Water
The following standards shall apply to all laboratory pure water:
a) Laboratory pure water shall have these characteristics:
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Value |
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Conductivity |
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Less than 2.0 micromhos/cm resistivity greater than 0.5 megohm-cm) + 1% at 25° C |
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Trace metals: |
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Individual metals (Cd, Cr, Cu, Ni, Pb, Zn) |
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Less than or equal to 0.05 mg/1 |
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Total metals |
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Less than or equal to 0.1 mg/1 |
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Test for bactericidal properties |
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of distilled water |
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Ratio of 0.8 to 3.0 |
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Free chlorine residual |
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None |
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Heterotrophic plate count |
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Less than 500/ml |
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b) Laboratory pure water shall be analyzed initially and annually thereafter by the test for bacteriological quality of distilled water as specified in "Standard Methods for the Examination of Water and Wastewater." Purchased laboratory pure water shall be sampled in-house; manufacturer's test results shall not be used to establish compliance. Only satisfactorily tested water shall be used in preparing media, reagents, rinse, and dilution water. If the water tested does not meet the testing requirements, the water shall not be used until corrective action has been taken and retesting determines the testing requirements have been met.
c) Laboratory pure water shall be analyzed monthly for conductance, chlorine residual, and heterotrophic plate count. Heterotrophic plate counts shall be performed as specified in "Standard Methods for the Examination of Water and Wastewater." If the water tested exceeds requirements for these properties, the water shall not be used until corrective action has been taken and retesting determines the testing requirements have been met.
d) Laboratory pure water shall not be in contact with heavy metals, and shall be analyzed initially and annually thereafter for trace metals (especially Pb, Cd, Cr, Cu, Ni, and Zn) in the quantities specified in subsection (a) of this Section. If the water tested exceeds requirements for trace metals, the water shall not be used until corrective action has been taken and retesting determines the testing requirements have been met.
e) The following quality control tests for heterotrophic plate count shall be utilized:
1) Sterility controls shall be poured for each bottle of sterile, melted, tempered medium used.
2) Sterility of pipets and petri dishes shall be determined.
3) Microbial density of the air during plating procedures shall be determined for each series of samples plated. When 15 or more colonies appear on an exposed plate after a 15 minute exposure period and 48 hours of incubation at 35º C, corrective action shall be taken.
4) The sterility of dilution water, if used, shall be determined.
5) Records of all sterility test results shall be maintained.