Laboratory of Pathology - Staff

Temperature Checks

Scope

Temperatures must be checked and recorded each day for all temperature-dependent equipment and environments using a calibrated or traceable thermometer. This includes the requirement for monitoring temperatures on days of patient testing, and on days the laboratory is closed to ensure the quality of the material stored within each temperature-dependent unit.

This Standard Operating Procedure (SOP) describes the correct procedures for monitoring/recording and addressing temperature variances of equipment and environments requiring a controlled temperature range. The SOP specifies requirements for documenting daily temperatures in accordance with regulatory standards, and ensuring appropriate corrective actions are taken in the event of a temperature deviation outside of accepted parameters. Temperature and min/max logs can be found on the Forms and Checklists page. 

Responsibilities

The Medical Director will ensure all laboratory staff adhere to temperature monitoring, addressing outliers, and appropriate documentation of laboratory temperature records. S/he will ensure adequate policies and procedures are implemented and used for laboratory temperature control.

The Section Technical Director/Supervisor will ensure all staff in their section(s) are adequately trained and comply with temperature control policies and procedures for their clinical area(s).

The Section General Supervisor will ensure all laboratory equipment are functioning appropriately, and will review temperature control logs monthly to ensure temperature checks are completed and appropriate corrective actions are taken if necessary.

All technical staff responsible for daily monitoring of laboratory temperatures should have initial training prior to performing their duties, and staff should be reassessed during annual competency assessments. It is recommended that annual technician/technologist competency assessments include some elements of quality assurance and preventative maintenance, and control documentation and corrective action would be a recommended competency element to include. 

Policy

Instruments, equipment, kits, or supplies that have specified temperature ranges for proper operation, storage, or use, must have records documenting that the specified ambient temperatures are/were maintained and corrective action taken when tolerance limits are exceeded.  Temperature-dependent equipment (e.g. refrigerators, freezers, incubators) containing reagents and/or patient/client specimens must be monitored daily, as equipment failures could affect accuracy of patient/client test results. Items such as water baths and heat blocks used for procedures need only be checked on days of patient/client testing. For heat blocks or dry baths, thermocouple probes may be used as an alternative method for checking the temperature. 

Temperature monitoring must be carried out by using a NIST-certified or traceable thermometer. If using a thermometer with a probe, the probe should be positioned towards the middle of the unit and away from the door, light and/or fan. If using a liquid thermometer, place the thermometer in a glycerin bottle or in an unobstructed location within the unit.

Acceptable temperature ranges must be defined and documented on the logs for all temperature-dependent equipment and environments (including ambient temperature) in accordance with manufacturer's instructions. Typical temperature ranges for clinical laboratory equipment and environments, unless otherwise specified by the manufacturer:

If a minimum/maximum thermometer is used to perform continuous monitoring of temperatures between daily temperature readings or following a laboratory downtime (e.g. laboratory closure for weekend or holiday), both the low and high temperatures must be recorded. To ensure correct temperature readings, the minimum/maximum thermometer device must be reset prior to the next monitoring period.

Corrective Action

If a temperature record exceeds the high or low limits for temperature-dependent equipment or environments, corrective action to resolve the temperature variance is required. The general or technical supervisor should be notified of any out-of-range temperatures, and of the corrective action step(s) taken. If the temperature variance does not resolve with simple troubleshooting techniques and if the time out-of-range places the contents at risk, the contents must be transferred to another temperature-controlled unit.

Corrective action could include, but is not limited to:

• If the unit was recently opened, allow it to remain closed for 15 minutes and recheck the temperature. If resolved, document in the corrective action section, and no further action is necessary.
• If the unit is a frost-free unit, it should not require defrosting. However, if there is ice buildup, remove excess ice and recheck the temperature after defrosting.
• If a refrigerator or freezer has a fan filter, clean dust/dirt from the filter. Consider also that the until may need coolant, which would require a service technician call.
• If the out-of-range high is the ambient room temperature, contact facility management (301) 435-8000 and request corrective action.
• If a recheck fails repeatedly post-troubleshooting, transfer the contents to another unit and contact biomedical services or the service provider vendor to request repair of the unit. 
• If a unit is out of service, place an Out-Of-Service sign on the front of the unit so that all staff know not to use the equipment.

Management of Reagents or Samples

If a temperature failure is identified for a period longer than 30 minutes, additional investigation to determine if any potential adverse effects resulted from the temperature error is required. For example:

• Temperature-dependent reagents, test kits, controls, calibrators or media stored in a refrigerator that failed min/max over the weekend must have an investigation of the accuracy of quality of the material before use for patient testing.
• Frozen tissue samples in the liquid nitrogen cryofreezer or ultralow freezer should be evaluated by the PI to determine how to test the sample.
• Consult the general or technical supervisor to seek guidance on how to investigate the quality of contents, and document all corrective actions taken on the temperature control log.

The unit must be re-certified within temperature range before any contents can be returned to the unit.

Records Management

Temperature logs must be kept on file in the laboratory for no less than 2 years.

NIST certificates for each thermometer and/or thermometer calibration records must be kept in the laboratory throughout the use of the thermometer. Thermometers will not be used beyond the calibration expiration date.