Virginia Administrative Code › Title 1 - ADMINISTRATION › Agency 30 - DEPARTMENT OF GENERAL SERVICES › Chapter 45 - CERTIFICATION FOR NONCOMMERCIAL ENVIRONMENTAL LABORATORIES › Part II - Standards › Article 4 - Proficiency Testing › Section 1VAC30-45-798 - Microbiology testing: constant and consistent test conditions

Current through Register Vol. 40, No. 24, July 15, 2024
A. Laboratory
					 facilities. Floors and work surfaces shall be nonabsorbent and easy to clean
					 and disinfect. Work surfaces shall be adequately sealed. Laboratories shall
					 provide sufficient storage space, and shall be clean and free from dust
					 accumulation. Plants, food, and drink shall be prohibited from the laboratory
					 work area.
B. Laboratory equipment.
1. Temperature measuring devices. Temperature
					 measuring devices such as liquid-in-glass thermometers, thermocouples, and
					 platinum resistance thermometers used in incubators, autoclaves and other
					 equipment shall be the appropriate quality to meet specifications in the test
					 method. The graduation of the temperature measuring devices shall be
					 appropriate for the required accuracy of measurement and they shall be
					 calibrated to national or international standards for temperature (see
					 1VAC30-45-740 C). Calibration shall
					 be done at least annually.
2.
					 Autoclaves.
a. The performance of each
					 autoclave shall be initially evaluated by establishing its functional
					 properties and performance, for example, heat distribution characteristics with
					 respect to typical uses. Autoclaves shall meet specified temperature
					 tolerances. Pressure cookers shall not be used for sterilization of growth
					 media.
b. Demonstration of
					 sterilization temperature shall be provided by use of continuous temperature
					 recording device or by use of a maximum registering thermometer with every
					 cycle. Appropriate biological indicators shall be used once per month to
					 determine effective sterilization. Temperature sensitive tape shall be used
					 with the contents of each autoclave run to indicate that the autoclave contents
					 have been processed.
c. Records of
					 autoclave operations shall be maintained for every cycle. Records shall include
					 date, contents, maximum temperature reached, pressure, time in sterilization
					 mode, total run time (may be recorded as time in and time out) and analyst's
					 initials.
d. Autoclave maintenance
					 shall be performed annually, either internally or by service contract, and
					 shall include a pressure check and calibration of temperature device. Records
					 of the maintenance shall be maintained in equipment logs. If the laboratory
					 demonstrates regular monitoring of pressure (e.g., for each autoclaved batch)
					 and annual calibration of the maximum registering thermometer, the annual
					 autoclave pressure and temperature device checks shall not be
					 required.
e. The autoclave
					 mechanical timing device shall be checked quarterly against a stopwatch and the
					 actual time elapsed documented.
3. Volumetric equipment. Volumetric equipment
					 shall be calibrated as follows:
a. Equipment
					 with movable parts such as automatic dispensers, dispensers/diluters, and
					 mechanical hand pipettes shall be verified for accuracy quarterly.
b. Equipment such as filter funnels, bottles,
					 nonclass A glassware, and other marked containers shall be calibrated once per
					 lot prior to first use.
c. The
					 volume of the disposable volumetric equipment such as sample bottles and
					 disposable pipettes shall be checked once per lot.
4. UV instruments. UV instruments used for
					 sanitization shall be tested quarterly for effectiveness with an appropriate UV
					 light meter or by plate count agar spread plates. Replace bulbs if output is
					 less than 70% of original for light tests or if count reduction is less than
					 99% for a plate containing 200 to 300 organisms.
5. Conductivity meters, oxygen meters, pH
					 meters, hygrometers, and other similar measurement instruments shall be
					 calibrated according to the method specified requirements (see
					 1VAC30-45-740 D 1 d).
6. Incubators, water baths, and ovens.
a. The uniformity of temperature distribution
					 in incubators and water baths shall be established. Temperature of incubators
					 and water baths shall be documented twice daily, at least four hours apart, on
					 each day of use.
b. Ovens used for
					 sterilization shall be checked for sterilization effectiveness monthly with
					 appropriate biological indicators. Records shall be maintained for each cycle
					 that include date, cycle time, temperature, contents and analyst's
					 initials.
7. Labware
					 (glassware and plasticware).
a. The laboratory
					 shall have a documented procedure for washing labware, if applicable.
					 Detergents designed for laboratory use shall be used.
b. Glassware shall be made of borosilicate or
					 other noncorrosive material, free of chips and cracks, and shall have readable
					 measurement marks.
c. Labware that
					 is washed and reused shall be tested for possible presence of residues that may
					 inhibit or promote growth of microorganisms by performing the Inhibitory
					 Residue Test annually, and each time the lab changes the lot of detergent or
					 washing procedures.
d. Washed
					 labware shall be tested at least once daily, each day of washing, for possible
					 acid or alkaline residue by testing at least one piece of labware with a
					 suitable pH indicator such as bromothymol blue. Records of tests shall be
					 maintained.