Section 465.400  Quality Controls for Media, Equipment and Supplies

The following minimum requirements shall apply to quality control checks of laboratory media, equipment, and supplies:

a)         The pH meter or meters shall be standardized before each use period with pH 7.0 and either pH 4.0 or pH 10.0 standard buffers, whichever range covers the desired pH of the media or reagent. A record of the standardization, including the percent slope, shall be maintained. Percent slope shall be 95 to 105%. If the pH meter does not have a feature to automatically calculate the slope, but can provide the pH in millivolts, the following formula shall be used: Slope (as %) = mV at pH 7 – mV at pH 4 or pH 10 X 1000/77. Each buffer aliquot shall be used only once. Commercial buffer solutions shall be dated. Do not use past the expiration date. Maintain electrodes according to manufacturer's recommendations.

b)         Balances shall be calibrated monthly using NIST standardized Class "S" or "S-1", or equivalent ASTM 1, 2, or 3 weights. A minimum of three weights that bracket the weighing requirements of the laboratory shall be used, and these weights shall be recertified every five years. A certificate listing correction data shall accompany the weights. Electronic balances shall be calibrated annually by a qualified service representative who is not affiliated with the laboratory. A certificate of calibration from the service representative shall be available for inspection.

c)         Glass and electronic thermometers and temperature-recording devices shall be calibrated annually at temperature of use against an NIST certified thermometer to within ± 1.0° C. NIST-certified thermometers shall be checked at the ice point annually and recalibrated at least every five years at each temperature of use. The calibration factor, date calibrated, temperature of calibration, and analyst's initials shall be tagged on each thermometer.  In addition, the laboratory shall record the following information in a Quality Control (QC) record book:

1)         Serial number or unique identifier of laboratory thermometer;

2)         Serial number of NIST-traceable thermometer;

3)         Temperature of laboratory thermometer;

4)         Temperature of NIST-traceable thermometer;

5)         Correction (or calibration) factor;

6)         Date of calibration; and

7)         Analyst's initials.

d)         Temperature in incubation equipment shall be recorded continuously by a temperature-recording device or recorded twice daily (at times separated by at least four hours) from in-place thermometers immersed in liquid and placed on the top and bottom shelves of the use area.  Documentation shall include the date and time of reading, temperature (as determined using the correction factor of the thermometer in use), and analyst's initials. Temperature readings from walk-in incubators with a continuous temperature reading device shall be supplemented by readings from in-place thermometers placed on various shelves other than where the recorder probe is located.

e)         Date, contents, sterilization time and temperature, total time in autoclave, and analyst's initials shall be recorded each time the autoclave is used. Charts, if used, are to accompany written records.

f)          Hot air ovens shall be equipped with a thermometer registering up to at least 180º C, or with a temperature-recording device. The oven thermometer shall be graduated in 10º C increments or less, with the bulb placed in sand during use. Date, contents, sterilization time and temperature, total time in oven, and analyst's initials shall be recorded each time the hot air oven is used.

g)         Only membrane filters recommended for water analysis by the manufacturer shall be utilized. Manufacturer data sheets containing information as to lot number, ink toxicity, recovery, retention, and absence of growth-promoting substances for membrane filters shall be entered into the laboratory's record system. Membrane filters with new lot numbers shall be compared with membrane filters previously found acceptable using student's t test as specified in Standard Methods. Unacceptable membranes shall be returned to the vendor. The lot numbers of membrane filters and date received shall be recorded.

h)         Washing processes shall provide clean glassware with no stains or spotting.  Use distilled or deionized water for final rinse.  Laboratory glassware shall be washed with a detergent designed for laboratory use. A glassware inhibitory residue test (Standard Methods, Section 9020B, under Laboratory Supplies) shall be performed, and acceptable results obtained, before the initial use of a detergent and whenever a different formulation, lot number, container or washing procedure is used. Results shall be recorded.  

i)          A representative piece of each type of glassware or plastic ware from each batch of clean, dried glassware or plastic ware shall be tested for residual alkaline or acid residue using bromothymol blue indicator.  If the result of the indicator test is not green, corrective action shall be taken by re-rinsing, then air drying and retesting.

j)          At least one bottle per batch of sterilized sample bottles shall be checked for sterility by adding approximately 25 ml of sterile non-selective broth media to each bottle. The bottle shall be capped and rotated so that the broth comes in contact with all surfaces and shall be incubated at 35º + 0.5º C and checked after 24 and 48 hours for growth.  Prepared sample bottles from each batch shall not be used unless satisfactory results are obtained from the tested bottle.

k)         At least one bottle per batch of sterilized sample bottles prepared with sodium thiosulfate shall be checked for sufficient amount of the dechlorinating reagent by collecting a potable sample at the laboratory tap, then checking for residual chlorine. Corrective action shall be taken if there is any residual chlorine, and bottles from the batch checked shall not be used until corrective action has been completed.

l)          Current service contracts or in-house protocols shall be maintained on balances, autoclaves, hot-air sterilization ovens, water stills, deionizers, reverse osmosis apparatus, water baths, incubators, etc. Service records on such equipment shall include the date, name of the servicing person, and a description of the service provided.

m)        Records shall be available for inspection on all batches of sterilized media showing type of medium, lot numbers, date, sterilization time and temperatures, final pH, and name of the persons responsible for all or any part of the recorded data. The final pH of the medium at 25° C shall be:

n)         Lactose broth may be used in lieu of LTB if the laboratory conducts at least 25 parallel tests between this medium and LTB using water normally tested and this comparison demonstrates that the false-positive rate and false-negative rate for total coliforms, using lactose broth, is less than 10%.

o)         A maximum registering thermometer shall be used during each autoclave and hot air oven cycle to verify sterilization temperatures.  The oven maximum registering thermometer shall be placed in sand. The autoclave maximum registering temperature shall be placed in a container of water. Use spore strips or ampules on a monthly basis, including a positive control. Spore strips shall be used monthly to confirm sterilization for the hot air oven. Do not use ampules because they may explode or melt. A record of these results shall be maintained to include the date, material sterilized, and the initials of the analyst involved. Check automatic timing mechanisms on autoclaves quarterly with a stopwatch. For a 15-minute sterilization period, the autoclave time shall be within 60 seconds of the clock time.

p)         When a media-dispensing apparatus is used, the media preparer shall check and maintain a record of the accuracy of the dispenser with a graduated cylinder at the start of each volume change and periodically throughout extended runs.

q)         The refrigerator temperature shall be determined daily by an accurate thermometer immersed in liquid and placed on the top shelf. The refrigerator unit shall be visibly clean. Outdated materials in the refrigerator and freezer compartments shall be discarded.

r)          Ultraviolet sterilization lamps shall be tested quarterly by exposing agar spread plates containing 200 to 250 microorganisms to the light for two minutes. If such irradiation does not reduce the count of control plates by 99 percent, the lamps shall be replaced. Alternatively, replace lamps if they emit less than 70% of the initial output. Cleaning of ultraviolet sterilization lamps shall be done at least monthly by disconnecting the unit and cleaning the lamps with a soft cloth moistened with ethanol. Use protective eye wear when checking the operation of a 254 nm lamp.

s)         Water baths shall be cleaned at least monthly. The use of distilled or deionized water for water baths is recommended.

t)          Media shall be used on a first in, first out basis. Records shall be kept of the kind, amount, date received, and date opened for bottles of media. The date opened and the date received shall be written on the bottles. Bottles of dehydrated media shall be used within six months after opening, except that media stored in a desiccator may be used up to one year after opening. It is recommended that media be ordered in quantities to last no longer than one year, and that media be ordered in quarter pound multiples rather than one pound bottles in order to keep the supply sealed and protected as long as possible. Any media that have passed the manufacturer's expiration date shall be discarded.

u)         Calibrate the conductivity meter at least monthly, following the manufacturer's recommendations, using a certified and traceable low level standard of 20 micromhos or less. The meter reading shall be within 2% of the value of the standard. If an in-line unit cannot be calibrated, it shall not be used to check reagent-grade water.

v)         A spectrophotometer or colorimeter (if used) shall have wavelengths in the visible range. A calibration standard and method specific blank shall be analyzed every day that the instrument is used prior to sample analysis. The calibration standard shall give a reading in the desired absorbance range and shall be obtained from an outside source.

w)        Check each batch of prepared or each lot of commercial dilution/rinse water for sterility by adding 50 mL of water to 50 mL of double-strength, nonselective broth. Incubate at 35° ± 0.5° C, and check for growth after 24 and 48 hours. Discard batch if growth is detected.

x)         Check each batch of prepared or each lot of commercial dilution water blanks for pH; pH shall be 7.2 ± 0.2.

y)         Check one of 25 dilution water blanks per batch of prepared lot of commercial dilution water blanks for volume using a Class A graduated cylinder or a MacCaffrey flask.  Volume shall be 99 mL ± 2 mL.

(Source:  Amended at 35 Ill. Reg. 14494, effective August 12, 2011)