US Environmental Protection Agency Office of Pesticide Programs Office of Pesticide Programs Microbiology Laboratory Environmental Science Center, Ft. Meade, MD Standard Operating Procedure for Performance Verification of the Yamato Drying Oven (Mechanical Convection Oven) SOP Number: QC-23-01 Date Revised: 07-23-09 ------- Initiated By: Technical Review: QA Review: SOP No. QC-23-01 Date Revised 07-23-09 Page 1 of 10 EPA/OPP MICROBIOLOGY LABORATORY ESC, Ft. Meade, MD Standard Operating Procedure for Performance Verification of the Yamato Drying Oven (Mechanical Convection Oven) SOP Number: QC-23-01 Date Revised: 07-23-09 Print Name: Print Name: Technical Staff Print Name: QA Officer Date: / / Date: / / Date: / / Approved By: Print Name: Branch Chief Date: / / Effective Date: / / Controlled Copy No.: Withdrawn By: Date: / / ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 2 of 10 TABLE OF CONTENTS Contents Page Number 1.0 SCOPE AND APPLICATION 3 2.0 DEFINITIONS 3 3.0 HEALTH AND SAFETY 3 4.0 CAUTIONS 3 5.0 INTERFERENCES 3 6.0 PERSONNEL QUALIFICATIONS 3 7.0 SPECIAL APPARATUS AND MATERIALS 4 8.0 INSTRUMENT OR METHOD CALIBRATION 4 9.0 SAMPLE HANDLING AND STORAGE 4 10.0 PROCEDURE AND ANALYSIS 4 11.0 DATA ANALYSIS/CALCULATIONS 7 12.0 DATA MANAGEMENT/RECORDS MANAGEMENT 7 13.0 QUALITY CONTROL 7 14.0 NONCONFORMANCE AND CORRECTIVE ACTION 7 15.0 REFERENCES 8 16.0 FORMS AND DATA SHEETS 8 ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 3 of 10 1.0 SCOPE AND APPLICATION: 1.1 This protocol describes procedures for the verification of performance for the Yamato drying oven. 2.0 DEFINITIONS: 2.1 NIST = National Institute of Standards and Technology 3.0 HEALTH AND SAFETY: 3.1 When operating ovens, always observe the following safety precautions: • Wear insulated gloves • Use tongs • Never stand in front of an open operating oven • Use safety glasses 3.2 As a safety precaution, disconnect the power cord from the power source when inspecting or maintaining this unit. Prior to each use, perform inspection and maintenance procedures. To clean, wipe the unit with a soft cloth dampened with de-ionized water. Using tap water on this unit may attract dirt. 4.0 CAUTIONS: 4.1 Since drying ovens use high temperatures, it is necessary to exercise extreme caution around the device. High-temperature surfaces can be encountered even when the device is not in a sterilizing cycle. 4.2 Be cautious when opening and closing the door. 4.3 Do not place items directly on bottom plate of the oven. This will disturb the performance and furthermore, the internal temperature and will cause malfunctions. Be sure to utilize the shelves provided. 5.0 INTERFERENCES: 5.1 Follow storage conditions for Dry Heat and Biological Indicator Spore Strips as specified in section 9.0. 6.0 PERSONNEL QUALIFICATIONS: 6.1 Personnel are required to be knowledgeable of the procedures in this SOP. Documentation of training and familiarization with this SOP can be found in the training file for each employee. ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 4 of 10 7.0 SPECIAL APPARATUS AND MATERIALS: 7.1 Drying oven located in B209, Yamato Mechanical Convection Oven, Model DKN810, Serial Number DKN811B4600129 7.2 Raven Biological Laboratories Dry Heat Indicator Labels 7.3 Drytrol Sterilization Monitors for Dry Heat 7.4 Raven Biological Laboratories Spore Strips with 106 spores of Bacillus atrophaeus (ATCC #9372) 7.5 Raven Biological Laboratories Soybean Casein Digest Broth 7.6 Incubator with temperature at 30°C ± 1°C 7.7 NIST traceable digital thermocouple: Fisher Scientific Thermocouple, Model Number 15-077-14, Serial Numbers 230317798 and 41299983 8.0 INSTRUMENT OR METHOD CALIBRATION: 8.1 Thermocouples are calibrated annually by Control Company, an ISO 17025 accredited laboratory. 9.0 SAMPLE HANDLING AND STORAGE: 9.1 Soybean Casein Digest Broth must be stored according to manufacturer's specifications to insure shelf life. Care must be taken to insure that the box of broth tubes is unpacked immediately upon arrival and placed in the refrigerator. 9.2 Dry Heat Indicator Labels are to be stored according to manufacturer's specifications. Take care to protect from moisture and excessive humidity. 9.3 Biological Indicator Spore Strips are to be stored according to manufacturer's specifications. Take care to protect from sterilizing agents, avoid sunlight, and all other forms of UV light. DO NOT REFRIGERATE. 10.0 PROCEDURE AND ANALYSIS: 10.1 Summary: 10.1.1 Drying Oven performance will be verified by examining the spore strips, Drytrol sterilization monitors, and Dry Heat Indicator Labels. Specifically, ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 5 of 10 the indicator labels and Drytrol sterilization monitors will be used with every sterilization run. The indicator labels, Drytrol sterilization monitors, and spore strips will be used for the monthly performance verifications described in Section 10.2. Table 10.1.1 Performance Verification Elements for the Drying Oven Room and Unit ID Dry Indi< La Heat :ator aels Drytrol Sterilization Monitors Spore Strips R* M* R* M* R* M* B209 Drying Oven ~ ~ N/A ~ * R = Routine (per load) M = Monthly N/A = Not Applicable 10.2 Performance Verification Procedures for the Drying Oven. 10.2.1 Entering/Verifying Settings for Digital Temperature Logger (To be performed with each cycle) 10.2.1.1 Press set button. It will display a warning message, press set again. "Set time/Div" is displayed. At this point logger will reset. 10.2.1.2 At the "Set time/Div" select the 1 hour/div. Press set again. 10.2.1.3 At the "Set V Scale" select the 0 to 250. Press set again. 10.2.1.4 At the "Set F or C" select Celsius. Press set again. 10.2.1.5 At the "Set Date" enter in date using the arrow keys. Press set again. 10.2.1.6 At the "Set Time" enter in time using the arrow keys. Press set again. 10.2.2 Entering/Verifying Settings for Drying Oven 10.2.2.1 Press timer button. "AStp" (auto-stop) will be displayed. Press enter. ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 6 of 10 10.2.2.2 "SV" (set temperature) will be displayed. Use arrow keys to set to 180. Press enter. 10.2.2.3 "Tim" (set time) will be displayed. Use arrow keys to set to 2.00. Press Start/Stop till oven clicks on. 10.2.3 Routine Runs (Per Load) 10.2.3.1 Dry Heat Indicator Labels. Place one label on each item to be sterilized. Do not attach to glass. Indicator label will turn black then exposed to heat. NOTE: Dry Heat Indicator Labels are used to visually verify that items have been through a drying cycle. Labels DO NOT indicate sterilization. 10.2.3.2 Drytrol Sterilization Monitors. Randomly place two indicators per shelf being utilized. Place inside glassware. Sterilization occurs when the pellet inside changes color from blue to pink. 10.2.3.3 Record results on the appropriate forms. (See 16.1) Results of the Dry Heat Indicator labels are observed only; a deviation is documented if any of these indicators fail to turn black. Those items with labels that did not turn black must be re-sterilized. 10.2.4 Procedures for Monthly Performance Verification for the Drying Oven. 10.2.4.1 Follow section 10.2.3.1. 10.2.4.2 Place three Drytrol sterilization monitors on each shelf being used. Place one towards the front, one in the middle, and one towards the back inside the various glassware. Sterilization occurs when the pellet inside changes color from blue to pink. 10.2.4.3 In addition, use spore strips: 10.2.4.3.1 Place two strips in glass Petri dishes between two pieces of filter paper. Place a strip in a 100 mL flask and one more in a 1000 mL screw top bottle with both tops wrapped in foil. Randomly place the glassware with spore strips throughout the oven. 10.2.4.3.2 Remove strips and aseptically place each one into a separate vial of Raven Biological Laboratories Soybean Casein Digest Broth. Place an untreated ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 7 of 10 spore strip into a separate vial of broth to serve as a positive control. Place vials into a 30°C ± 1°C incubator for up to 7 days. 10.2.4.3.3 Observe daily for growth. If turbidity is present in the broth, proper sterilization was not achieved. Confirm the growth as the test organism by Gram stain (Gram positive large rods). If growth of the test organism is confirmed, then that sterilization cycle failed and all glassware from that cycle must be resterilized. Refer to Table 14.1. 10.2.4.3.4 Refer to Table 14.1 for interpretation of results. Record results on the appropriate forms (See 16.2). 11.0 DATA ANALYSIS/CALCULATIONS: 11.1 See Table 14.1 for interpretation of results. 12.0 DATA MANAGEMENT/RECORDS MANAGEMENT: 12.1 Data will be recorded promptly, legibly, and in indelible ink. Information on daily drying oven runs will be recorded on the Routine Sterilization Record Information Form (see 16.1). Information on monthly QC drying oven runs will be recorded on the Monthly Sterilization Record Information Form (see 16.2). Completed forms are archived in notebooks kept in secured file cabinets in file room D217. Only authorized personnel have access to the secured files. Archived data is subject to OPP=s official retention schedule contained in SOP ADM-03, Records and Archives. 13.0 QUALITY CONTROL: 13.1 Performance verification of the Yamato drying oven is conducted with each load as described in sections 10.2.3, and is conducted monthly as described in sections 10.2.4. See Table 10.1 for a summary of performance verification requirements. 14.0 NONCONFORMANCE AND CORRECTIVE ACTION: 14.1 Refer to Table 14.1 for interpretation of results and appropriate corrective actions for nonconformance. ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 8 of 10 Table 14.1 Interpretation of Results Drytrol Spore Strips Interpretation of Results and Corrective Action for the Yamato Drying Oven Pass Pass Indicates all parameters have passed. Fail Fail Indicates that oven did not reach sterilization temperature for the required time. Repeat monthly performance verification. If still nonconformance, tag out of service and call for service. Fail Pass Indicates that oven has sterilized contents. Drytrol failed. No corrective action needed. Pass Fail Indicates that oven has reached sterilization temperature but has not sterilized contents. Repeat monthly performance verification. Fail N/A Indicates that oven did not reach sterilizing temperature. Repeat daily cycle. 15.0 REFERENCES: 15.1 Instruction Manual for Yamato Mechanical Convection Oven DKN-810, Yamato Scientific America, Inc. Ver.3 December 27, 2003. 15.2 Eaton, A.D., Clesceri, L.S., Rice, E.W., Greenberg, A.E. eds. Standard Methods for the Examination of Water and Wastewater, Online Edition. American Public Health Association, American Water Works Association, Water Environment Federation, Section 9020 approved 2005. 16.0 FORMS AND DATA SHEETS: 16.1 Routine Sterilization Record Log Form for Drying Oven. 16.2 Monthly Sterilization Record Log Form for Drying Oven. ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 9 of 10 16.1 Routine Sterilization Record Log Form for Drying Oven OPP Microbiology Laboratory Drytrol Sterilization Monitor Results' Items Processed Sterilization No." Temp' Init. 1. Record the results for each of the Drytrol Sterilization Monitors as "P" for pass or "F" for fail, i.e., for 6 monitors, enter 6 P's. 2. The Sterilization No. indicates the date as well as the unit location and the run number. (S-MMDDYY-9XX, S=sterilization, 9=room 209, XX=run number) 3. Record the temperature reading of the thermocouple at approximately the mid-point of the cycle. ------- SOP No. QC-23-01 Date Revised 07-23-09 Page 10 of 10 16.2 Monthly Sterilization Record Log Form for Drying Oven OPP Microbiology Laboratory Init. Sterilization Run No.1 Drytrol Sterilization Monitor Results Soybean Casein Digest Broth Control No. Temp3 Date/ Init Spore Strip Results4 Spore Strip Control No. 1 2 3 4 1. The Sterilization No. indicates the date as well as the unit location and the run number. (S-MMDDYY-9XX, S=sterilization, 9=room 209, XX=run number) 2. Record the results for each of the Drytrol Sterilization Monitors as "P" for pass or "F" for fail, i.e., for 6 monitors, enter 6 P's. 3. Record the temperature reading of the thermocouple at approximately the mid-point of the cycle. 4. Record positive results of the spore strips for up to 7 days as "G" for Growth (Fail) and on the 7th day if no growth record negative results as "N" for No Growth (Pass). ------- |