Calibration of temperature-controlled trucks and trailers (used for GDP-compliant transportation of pharmaceutical, biopharmaceutical, and healthcare products) is a critical requirement under Good Distribution Practice (GDP) to ensure that the temperature monitoring and control systems accurately maintain and record product storage conditions during transit.

Here’s a comprehensive explanation of what calibration means in this context — including objectives, processes, regulatory expectations, documentation, and best practices.

Good Distribution Practice (GDP) Trainings | GxP Cellators

 1. Purpose of Calibration

Calibration of temperature-controlled trucks and trailers is a critical quality and compliance activity under Good Distribution Practice (GDP). It ensures that the temperature monitoring and control devices used during pharmaceutical transport are accurate, reliable, and traceable to recognized standards.

1.1 Why Calibration Is Necessary

Temperature-sensitive pharmaceutical and biopharmaceutical products — such as vaccines, biologics, insulin, blood products, and certain antibiotics — must be maintained within defined temperature ranges throughout storage and transportation.
Any deviation from these limits can impact product quality, potency, or stability, leading to:

• Product degradation or loss of efficacy
• Regulatory non-compliance
• Product recalls or destruction
• Potential patient safety risks

Calibration provides documented assurance that all temperature measuring, monitoring, and controlling devices installed in the vehicle are performing accurately and reflecting true temperature conditions.

1.2 Calibration Ensures Accurate Readings

Objective:
To confirm that all temperature sensors, controllers, and data loggers used in trucks/trailers are providing accurate and precise temperature measurements within defined tolerances.

Explanation:

Each sensor or probe inside the refrigerated compartment continuously monitors the internal air temperature. Over time, due to mechanical wear, environmental stress, or sensor drift, these instruments may lose accuracy.

Calibration verifies that the readings from these devices match the readings of a certified reference standard (traceable to NIST, NRC, or equivalent).

Example:

Here, Sensor B deviates by +1.2°C, exceeding the allowable tolerance of ±0.5°C. This means the rear zone sensor must be recalibrated or replaced before use.

1.3 Ensures Consistent Temperature Maintenance

Objective:
To confirm that the temperature control system of the truck or trailer can consistently maintain the required temperature range throughout the transport cycle.

Explanation:

A calibrated system ensures that:

• The set point on the controller accurately reflects the actual air temperature.
• The refrigeration unit maintains uniform temperature distribution across all zones.
• Temperature deviations trigger alarm systems at the correct thresholds.

Calibration therefore minimizes risk of temperature excursions (e.g., going above +8°C or below +2°C for refrigerated transport).

Example (Refrigerated Truck, 2–8°C):

During a temperature mapping study:

• Front sensor: 4.8°C
• Middle sensor: 5.2°C
• Rear sensor: 7.6°C
  If calibration confirms all sensors are accurate within ±0.5°C, the system can be trusted to maintain stability.
  If one sensor shows drift, it may give false assurance — potentially masking a real excursion.

1.4 Ensures Data Integrity and Reliability

Objective:
To verify that the data loggers, monitoring systems, and recording devices generate accurate, reliable, and traceable data that can withstand regulatory scrutiny.

Explanation:

Regulators expect all temperature records (electronic or printed) used in product release and QA decisions to be accurate and trustworthy.
If a data logger or onboard recorder is not properly calibrated, even minor measurement errors could:

• Misrepresent actual storage conditions
• Lead to incorrect release decisions
• Compromise data integrity under GDP or FDA Part 11 expectations

Example:

• Data logger (Logger ID: LOG-001) shows: 8.1°C maximum during shipment
• Reference standard calibration shows true temperature: 9.0°C
• Result: Actual temperature exceeded 8°C limit → potential temperature excursion
  This example demonstrates how an uncalibrated logger can mask a real deviation, leading to non-compliance and potential product failure.

1.5 Ensures Compliance with Global GDP and Regulatory Requirements

Objective:
To ensure that the transportation process meets international GDP regulatory requirements that mandate regular calibration of all monitoring and control instruments.

Regulatory References:

Example of Compliance:

A Canadian distributor using 10 refrigerated trucks ensures:

• All sensors are calibrated annually using ISO 17025-accredited laboratory.
• Calibration certificates are traceable to NIST/NRC standards.
• QA reviews all calibration certificates before the vehicles are released for GDP operations.

During an MHRA GDP inspection, auditors may request:

• Last calibration date and certificate for each truck
• Proof of traceability to recognized standards
• Calibration procedure and tolerance acceptance limits

Failure to provide evidence results in GDP deficiency observations (e.g., “Equipment not calibrated at defined intervals,” “Certificates not traceable to national standards”).

1.6 Summary of Purpose

In summary, calibration ensures that:

1. Temperature readings are accurate → protecting product quality.
2. Temperature control systems are reliable → preventing excursions.
3. Recorded data are trustworthy → supporting release and audit decisions.
4. GDP and global regulatory requirements are met → maintaining compliance and avoiding warnings.

Practical Industry Example

A pharmaceutical logistics company transports mRNA vaccines (storage requirement: –70°C ±10°C).

• The truck’s digital display shows –72°C.
• After calibration against a certified probe, true temperature found to be –60°C.
• The discrepancy of 12°C indicates the display unit drifted significantly.
• The company immediately stops shipments using this vehicle, recalibrates sensors, and requalifies the system.
• QA documents deviation, investigates product impact, and implements tighter calibration frequency (every 6 months).

This action not only prevents regulatory non-compliance but also protects millions of dollars’ worth of sensitive vaccine product.

Good Distribution Practices (GDP) Certification

 2. Calibration Scope

Calibration of temperature-controlled trucks and trailers is not limited to a single instrument. It applies to all devices that monitor, control, or record environmental conditions, ensuring that pharmaceutical products remain within specified temperature and humidity ranges during transport. The following equipment is included in the calibration scope:

2.1. Temperature and Humidity Sensors / Probes

Purpose:
These sensors measure the actual conditions inside the cargo area. They are critical for ensuring the environment meets product-specific requirements.

Details:

• Temperature probes: Measure air or product temperature inside refrigerated, frozen, or controlled room temperature compartments.
• Humidity sensors: Monitor relative humidity for products sensitive to moisture (e.g., certain biologics, vaccines, or lyophilized products).
• Examples:
  • PT100 or PT1000 temperature probes installed at the front, middle, and rear of the cargo area.
  • Capacitive humidity sensors maintaining 40–60% RH for hygroscopic materials.

Calibration Requirement:

• Must be calibrated against traceable reference standards.
• Check readings at multiple points across operational ranges (e.g., –20°C, 0°C, 5°C, 25°C for temperature; 30%, 50%, 70% for RH).

Example Table:

2.2.  Temperature Controllers and Display Units

Purpose:
Controllers regulate the HVAC/refrigeration unit to maintain the target temperature. Display units provide real-time readings for operators.

Details:

• Controllers: PID controllers or integrated refrigeration system controllers that maintain setpoint temperature.
• Displays: Digital or analog displays showing real-time compartment temperature.
• Examples:
  • Controller setpoint: 5°C (2–8°C refrigerated transport)
  • Display shows 5.2°C → verify against calibrated reference probe.

Calibration Requirement:

• Verify that the display reading matches reference standards.
• Confirm that controller accurately triggers alarms when temperature deviates from the setpoint.

Example:

• Set controller to 5°C, reference probe reads 5.0°C, display shows 5.3°C → Deviation +0.3°C → Pass.

2.3.  Recorders / Data Loggers Integrated with the Truck System

Purpose:
These devices provide continuous electronic records of environmental conditions during transport. Records are critical for regulatory audits, batch release decisions, and excursion investigations.

Details:

• Types: Standalone loggers, integrated telematics, or cloud-based systems.
• Function: Log temperature at defined intervals (e.g., every 1–5 minutes).
• Examples: ELPRO, Sensitech, or TempTale loggers installed at multiple locations within the trailer.

Calibration Requirement:

• Must record accurate values within defined tolerances.
• Verify logger output against reference thermometer or simulator at multiple points.
• Include as-found and as-left readings for audit documentation.

Example:

• Logger shows 4.8°C at front zone, reference reads 5.0°C → deviation –0.2°C → Pass.
• Logger records at 10-minute intervals → verified for timestamp accuracy and memory integrity.

2.4.  Wireless Monitoring Systems or Mapping Sensors Used During Transit

Purpose:
Wireless sensors and mapping devices track environmental conditions in real time and may transmit data to a central monitoring system.

Details:

• Wireless sensors often include temperature, humidity, and GPS location tracking.
• Mapping sensors simulate product locations to verify temperature uniformity across all zones.
• Examples:
  • Bluetooth-enabled temperature probes for live tracking.
  • RFID-based or IoT-enabled environmental sensors for cold chain monitoring.

Calibration Requirement:

• Each sensor must be verified against a reference standard.
• Ensure signal integrity, timestamp synchronization, and data consistency with logger systems.

Example:

• A wireless probe in the rear cargo zone reads 5.5°C while reference reads 5.0°C → deviation +0.5°C → Pass.
• Check data transmission to the monitoring dashboard for accurate real-time recording.

2.5.  Any Alarm System Sensors

Purpose:
Alarms alert operators when temperature/humidity deviates outside predefined limits, preventing product compromise.

Details:

• Alarm sensors may be integrated with controllers, displays, or data loggers.
• Alarms include audible, visual, or remote notifications.
• Examples:
  • Low-temperature alarm <2°C in refrigerated compartment.
  • High-temperature alarm >8°C for 2–8°C transport.

Calibration Requirement:

• Verify that alarms activate at correct thresholds.
• Test both local alarm function and remote notification (if applicable).

Example:

• Simulate high temperature at 9°C → verify alarm activates and event is logged.
• Simulate low temperature at 1.5°C → alarm triggers within 1 minute → Pass.

Summary

Calibration of temperature-controlled trucks and trailers applies to all instruments critical to maintaining environmental conditions, including:

By calibrating all these devices, the transport system ensures GDP-compliant, reliable, and auditable temperature control for sensitive pharmaceutical and biopharmaceutical products.

Good Distribution Practices (GDP)

3. Calibration Frequency

Proper calibration frequency is essential to ensure that all temperature and humidity monitoring, control, and recording devices continue to operate accurately throughout the vehicle’s service life. The frequency is determined based on regulatory requirements, risk assessment, manufacturer recommendations, and product sensitivity:

3.1.  Annual Calibration (Standard GDP Practice)

Purpose:

• To maintain compliance with Good Distribution Practice (GDP) guidelines.
• Ensures that all sensors, controllers, and data loggers maintain their accuracy over time.

Rationale:

• Temperature sensors may drift gradually due to mechanical wear, vibration, environmental stress, or electronic aging.
• Annual calibration provides documented assurance for regulators that all equipment is operating within defined tolerance.

Regulatory Reference:

• EU GDP (2013/C 343/01): Equipment used for monitoring must be calibrated at defined intervals.
• WHO GDP (TRS 957, Annex 5): Calibration should occur at regular intervals.

Example:

• Truck TRK-001 has three sensors and one data logger. Last calibration was 10-Mar-2025.
• Next calibration is scheduled 10-Mar-2026 (12-month interval).

3.2.  Before Initial Qualification of the Vehicle

Purpose:

• To verify that the vehicle and all installed monitoring devices meet operational and regulatory requirements before first use for GDP transport.

Rationale:

• Ensures that sensors, controllers, and loggers are accurate and functioning properly during initial qualification studies, such as:
  • Temperature mapping (Operational Qualification, OQ)
  • Performance Qualification (PQ) during simulated transport

Example:

• A new refrigerated trailer is delivered to the warehouse.
• Calibration is performed on all installed sensors and controllers before performing temperature mapping.
• Reference thermometer readings match sensors within ±0.5°C → Vehicle qualifies for initial use.

3.3.  After Any Repair, Sensor Replacement, or System Modification

Purpose:

• To ensure that the repair or modification does not impact measurement accuracy or system functionality.

Rationale:

• Changes to the refrigeration unit, replacement of sensors, or software/firmware upgrades may affect the performance of temperature control and monitoring systems.
• Regulatory agencies expect re-validation or calibration after such changes.

Examples:

• Sensor Replacement: Rear cargo temperature sensor S3 replaced → calibration verifies new sensor matches reference readings.
• Refrigeration Unit Repair: Compressor replaced → post-repair calibration ensures system maintains uniform temperature.
• Controller Firmware Upgrade: Digital controller updated → calibration confirms setpoints and alarms function as expected.

Process:

• Perform calibration as soon as the system is restored.
• Record “as-found” and “as-left” readings for documentation and audit purposes.

3.4.  After Out-of-Tolerance (OOT) Calibration Results

Purpose:

• To confirm that the system has been corrected and is now within acceptable tolerance.

Rationale:

• When a sensor, controller, or data logger is found out-of-tolerance, it may compromise product integrity.
• Calibration must be re-performed after corrective actions (recalibration, adjustment, or replacement) to ensure compliance.

Example Scenario:

• During routine calibration: Sensor S2 reads 6.2°C, reference is 5.0°C → deviation +1.2°C (OOT, tolerance ±0.5°C).
• Corrective Action: Sensor S2 replaced and system stabilized.
• Post-correction calibration performed: Sensor now reads 5.1°C, reference 5.0°C → deviation +0.1°C → Pass.
• Vehicle cleared for product transport only after OOT resolution documented.

Additional Considerations for Determining Calibration Frequency

1. Risk Assessment:
   • Highly temperature-sensitive products (e.g., mRNA vaccines, biologics) may require more frequent calibration (every 6 months).
   • Low-risk products (e.g., CRT-stable items) may follow standard annual schedule.
2. Manufacturer Recommendations:
   • Some sensor or controller manufacturers specify calibration intervals shorter than 12 months.
   • Example: PT100 sensors recommend recalibration every 6–9 months due to possible drift.
3. Regulatory Expectations:
   • Inspections by FDA, MHRA, or EU GDP auditors expect evidence of calibration at regular intervals.
   • Missing calibration or lapses may result in observations, warning letters, or shipment holds.
4. Operational Events:
   • Accidental exposure to extreme temperatures or mechanical shock may require unscheduled calibration.
   • Example: A trailer exposed to –5°C ambient overnight → sensors should be checked before resuming shipments.

Summary Table of Typical Calibration Frequency

This detailed guidance ensures that all calibration activities are proactive, traceable, and compliant with GDP and regulatory expectations, preventing product excursions and regulatory non-compliance.

4. Calibration Process (Step-by-Step)

Step 1: Preparation

Objective:
Ensure all prerequisites, documentation, and equipment are ready before starting calibration activities.

Detailed Procedure:

1. Review Calibration SOP and Equipment List
   • Review the current version of the Calibration Standard Operating Procedure (SOP) to understand the scope, frequency, methods, and acceptance criteria.
   • Verify that the list of instruments and sensors installed in the truck/trailer (such as temperature probes, digital display sensors, and data loggers) is up to date.
   • Example:
     • Truck ID: TT-002
     • Installed Sensors:
       • Sensor-1 (Return Air)
       • Sensor-2 (Supply Air)
       • Sensor-3 (Door Zone)
       • Controller Display Sensor
     • All will be included in the calibration activity.
2. Identify All Sensors and Instruments Requiring Calibration
   • Prepare a calibration checklist identifying:
     • Sensor location
     • Sensor ID / Serial number
     • Manufacturer details
     • Last calibration date
     • Calibration due date
   • Example:

1. Verify Calibration Reference Standards
   • Ensure the reference standards (e.g., reference thermometers or simulators) used for calibration are traceable to national/international standards such as:
     • NIST (National Institute of Standards and Technology – USA)
     • NRC (National Research Council – Canada)
     • PTB (Physikalisch-Technische Bundesanstalt – Germany)
   • Confirm the reference instrument’s calibration certificate is valid and not expired.
   • Example:
     • Reference Thermometer Model: Fluke 1523
     • Calibration Certificate No.: FLK/2025/CT-011
     • Valid until: 15-Dec-2025

Step 2: Calibration Environment

Objective:
Ensure the calibration is conducted under stable, controlled conditions to minimize measurement error.

Detailed Procedure:

1. Vehicle Placement
   • Park the truck/trailer in a shaded or covered area, away from direct sunlight, strong wind, or rain to prevent temperature fluctuations.
   • Avoid locations with ambient temperature changes greater than ±2°C during the calibration activity.
   • Example:
     • Perform calibration in a temperature-controlled garage (ambient 20 ±2°C).
2. Temperature Control System
   • Ensure the truck/trailer’s refrigeration unit is turned off before calibration unless calibration is intended for the active system (i.e., verifying system function during operation).
   • If the calibration includes operational verification, set the unit to the intended temperature range (e.g., 2–8°C) and allow it to stabilize for at least 30–60 minutes before recording measurements.

Step 3: Calibration Execution

Objective:
Perform accurate calibration using certified reference standards and document all results.

Performed by:

• An accredited external calibration laboratory (ISO/IEC 17025 certified)
  or
• A qualified in-house technician trained in calibration procedures.

Detailed Procedure:

1. Compare Readings with Reference Standards
   • Use a calibrated reference thermometer or temperature simulator to compare against each installed sensor.
   • Record both readings (display and reference) and calculate deviation.
   • Example:
     • Sensor Reading: +4.8°C
     • Reference Reading: +5.0°C
     • Deviation = –0.2°C (within ±0.5°C tolerance → PASS)
2. Check at Multiple Temperature Points
   • Verify sensor accuracy at several key points across the operational range.
   • Example Temperature Points:
     • –20°C → for frozen transport validation
     • 0°C → for freezing point check
     • +5°C → for refrigerated range (2–8°C)
     • +25°C → for ambient storage (15–25°C)
   • Example Table:

1. Document and Adjust
   • Record all results on the Calibration Data Sheet or Vehicle Calibration Record Form.
   • If the deviation is outside acceptable tolerance, adjust or recalibrate the sensor as per manufacturer’s instructions.
   • Post-adjustment, recheck accuracy to confirm compliance.

Step 4: Post-Calibration Verification

Objective:
Ensure calibration results are properly documented, traceable, and system functionality is restored.

Detailed Procedure:

1. Affix Calibration Labels
   • Attach a calibration status label on each calibrated instrument, indicating:
     • Calibration Date
     • Next Due Date
     • Calibrated By
     • Equipment ID
   • Example Label:

• Calibrated: 01-Feb-2025
• Due: 31-Jan-2026
• By: Q-Tech Labs
• Equipment ID: T002

1. Update Calibration Certificates and Logs
   • File the calibration certificates in the Equipment Calibration File.
   • Update the Master Calibration Log to reflect the completion date and next due date.
2. Record All Results in the Vehicle Calibration Record
   • Maintain calibration data as per Good Documentation Practices (GDP) — entries must be legible, signed, and dated.
   • Example documentation includes:
     • Raw data sheets
     • Deviation reports
     • Certificates of calibration
     • Adjustments performed (if any)
3. Confirm System Alarms and Displays Function Properly
   • After calibration, restart the refrigeration unit (if applicable) and confirm:
     • Temperature display is accurate
     • Alarm system activates at pre-set limits (e.g., <2°C or >8°C)
     • Data logger records data correctly
   • Example:
     • Simulate over-temperature by setting controller to 10°C.
     • Verify alarm activates and event is recorded by data logger.

Example Reference Standards and Tolerances

5. Acceptance Criteria

Calibration acceptance criteria define the maximum allowable deviation between the readings of vehicle-installed sensors/data loggers and the reference standards. Correctly defined criteria ensure that temperature-sensitive products are protected from excursions, while also being auditable and compliant with regulatory requirements.

5.1 Basis for Acceptance Criteria

• Tolerance limits are derived from:
  • GDP Guidelines (EU, WHO, PIC/S)
  • ISO 17025 standards for calibration accuracy
  • Manufacturer specifications for sensors and data loggers
  • Product-specific stability requirements
• The key principle: All readings must be within defined limits across the entire operational range of the vehicle.
• Note: For highly sensitive products (e.g., mRNA vaccines), tolerances may be tightened further.

5.2 Typical Tolerance Limits

5.3 Examples of Application

Example 1: Refrigerated Truck (2–8°C)

• Sensor readings during calibration:

Interpretation: Middle zone sensor exceeds ±0.5°C → recalibration required before vehicle can be released for product transport.

Example 2: Controlled Room Temperature Vehicle (15–25°C)

• During CRT calibration:

Interpretation: Rear compartment sensor deviation exceeds ±1.0°C tolerance → adjustment needed.

Example 3: Frozen Vehicle (≤ –20°C)

• Frozen transport validation:

Interpretation: Rear zone sensor exceeds ±1.5°C → repair/replacement required. Critical for products like mRNA vaccines or monoclonal antibodies.

5.4 Factors Affecting Tolerance Limits

1. Product Sensitivity
   • Highly temperature-sensitive products may require tighter tolerances.
   • Example: mRNA vaccines → ±0.3°C for refrigerated transport instead of ±0.5°C.
2. Client SLA Agreements
   • Some clients specify stricter limits for monitoring and reporting.
   • Example: A contract requires data logger deviations ≤ ±0.2°C.
3. Sensor Type and Location
   • Air vs. product temperature sensors may have different acceptable deviations.
   • Example: Probe directly in product load may have ±0.3°C; ambient air sensor ±0.5°C.

5.5 Regulatory and Audit Relevance

• Regulators review calibration records and acceptance criteria during inspections.
• Deviations outside defined tolerance without documented corrective action may result in:
  • Observation (EU GDP, WHO GDP)
  • Warning Letter (FDA, MHRA)
  • Product Hold or Recall if transport conditions cannot be verified

Audit Example:
During an EU GDP inspection, auditors check a refrigerated truck:

• Sensor deviation: +0.8°C (tolerance ±0.5°C)
• Finding: Vehicle released without recalibration → Non-compliance noted → Corrective action required.

5.6 Summary Table for Quick Reference

6. Required Documentation

Proper documentation is a critical component of calibration activities. It ensures traceability, accountability, and compliance with regulatory requirements such as GDP, FDA, WHO, MHRA, EMA, and Health Canada. Well-maintained records provide evidence during audits, inspections, and internal quality reviews.

6.1.  Calibration SOP (Approved and Current)

Purpose:

• Establishes the standardized procedure for calibration of all temperature monitoring, controlling, and recording devices.
• Ensures uniformity across all vehicles and personnel performing calibration.

Details:

• Must include: scope, responsibilities, calibration steps, acceptance criteria, and post-calibration activities.
• Should be reviewed periodically and updated to reflect regulatory changes or process improvements.

Example:

• SOP No.: GDP/ENG/002
• Effective Date: 01-Jan-2025
• Revision No.: 02
• Approved by QA Head and Engineering Manager

Importance:

• Auditors often check whether calibration was performed according to an approved procedure.

6.2.  List of Calibrated Instruments with ID and Due Date

Purpose:

• Provides a master record of all sensors, data loggers, controllers, and reference instruments used in the fleet.
• Helps track calibration schedules and due dates, preventing lapses in compliance.

Details:

• Instrument ID / Serial Number
• Location in vehicle (front, rear, middle, supply air, return air)
• Manufacturer / Model
• Last calibration date
• Next due date

Example Table:

Importance:

• Prevents assignment of uncalibrated vehicles for product transport.
• Simplifies audit verification of calibration compliance.

6.3.  Calibration Certificates (Traceable to Standards)

Purpose:

• Provides official evidence that each device has been calibrated against a recognized reference standard.
• Ensures traceability to national/international standards (e.g., NIST, NRC, PTB).

Details:

• Issued by ISO 17025-accredited laboratory or qualified in-house technician.
• Must include:
  • Instrument ID and model
  • Reference equipment details
  • Calibration date
  • Tolerance limits
  • Measured deviations
  • Pass/Fail result

Example:

• Certificate No.: NIST/2025/056
• Instrument: Sensor T001
• Reference: PT100-021
• Result: Pass (±0.3°C deviation within ±0.5°C tolerance)
• Validity: 12 months

Importance:

• Regulatory inspectors (FDA, MHRA, EU GDP) require traceable certificates to ensure measurement accuracy and compliance.

6.4.  Calibration Status Labels

Purpose:

• Provides visual confirmation that a device has been calibrated and is fit for use.
• Helps operational personnel quickly identify calibrated and non-calibrated instruments.

Details:

• Label should include:
  • Calibration date
  • Next due date
  • Technician initials or lab name
  • Status (Pass / Fail)

Example Label:

CALIBRATED

Date: 01-Feb-2025

Next Due: 31-Jan-2026

Tech: ABC Lab

Status: PASS

Instrument ID: T002

Importance:

• Prevents use of out-of-calibration equipment, reducing risk of temperature excursions.

6.5.  Calibration Report

Purpose:

• Consolidates all calibration activities, measurements, and outcomes into a formal record for review, traceability, and audits.

Contents of Calibration Report:

1. Reference Equipment Details
   • Type, model, serial number, certificate number, and traceability.
   • Example: Fluke 1523 Reference Thermometer, Certificate FLK/2025/CT-011, Traceable to NIST.
2. Calibration Points
   • Record readings at multiple points across the operational range.
   • Example: –20°C, 0°C, +5°C, +25°C depending on vehicle type.
3. As-Found / As-Left Data
   • As-Found: Initial readings before adjustments.
   • As-Left: Final readings after calibration or adjustment.
4. Acceptance Decision
   • Indicates whether the device passes tolerance limits and is ready for use.
   • Example: PASS / FAIL
5. Technician Signature
   • Confirms that the calibration was performed by qualified personnel.
   • Includes date and contact info.

Importance:

• Serves as the primary document for QA review before vehicles are cleared for GDP operations.

6.6.  Change Control or Deviation Reports (if Calibration Out-of-Tolerance)

Purpose:

• Documents any issues when calibration results are out-of-tolerance (OOT) and the corrective/preventive actions (CAPA) taken.

Details:

• Initiate a Deviation Report for OOT readings.
• Conduct Impact Assessment for any product that may have been exposed to improper temperature.
• Record corrective actions: sensor repair/replacement, recalibration, updated frequency.
• Close the deviation only after QA review and approval.

Example:

• OOT Deviation Report: DR-2025-021
• Sensor S3 measured +6.1°C (tolerance ±0.5°C)
• Action: Sensor replaced, recalibrated, vehicle requalified
• QA Approval: 05-Mar-2025

Importance:

• Ensures regulatory traceability of all non-conformances.
• Prevents shipment of temperature-sensitive products under uncertain conditions.

Summary Table of Required Documentation

7. Regulatory References

EU GDP Guidelines (2013/C 343/01)

• Chapter 3.2.3: “Equipment used for monitoring of storage and transportation conditions should be calibrated at defined intervals.”
• Annex 15 (Qualification & Validation): Calibration of critical instruments shall be traceable to national standards.

WHO GDP (TRS 957, Annex 5)

• Section 5.3.2: “Temperature monitoring devices should be calibrated at regular intervals against a certified reference standard.”

Health Canada GUI-0069

• Requires periodic calibration and validation of temperature-controlled transport equipment.

FDA 21 CFR Part 211.68 & 211.160(b)(4)

• Instruments must be routinely calibrated, inspected, and checked for accuracy.

PIC/S PE 009-16 (Annex 15)

• Calibration and maintenance records must be retained and traceable.

8. Related Qualification Activities

Calibration is a fundamental activity, but it is closely linked to vehicle qualification studies, which ensure that transport conditions consistently meet the required temperature specifications. Qualification demonstrates that vehicles can maintain product integrity during real-world operations:

8.1.  Temperature Mapping Study (Operational Qualification, OQ)

Purpose:

• To verify the internal temperature distribution and sensor accuracy under controlled conditions before the vehicle is used for product transport.
• Ensures that the vehicle’s temperature monitoring and control system can maintain uniform conditions across all zones.

Key Activities:

1. Sensor Placement:
   • Install multiple sensors or data loggers at critical points inside the cargo area.
   • Typical zones: front, middle, rear, door area, top, bottom, supply air, return air.
2. Temperature Profiling:
   • Operate the refrigeration or heating system to reach target temperatures (e.g., 2–8°C for refrigerated products).
   • Record temperature readings over a defined period to capture steady-state conditions.
3. Data Analysis:
   • Compare sensor readings across all zones.
   • Identify any hot/cold spots or uneven distribution.
   • Evaluate the accuracy of installed sensors against calibrated reference instruments.

Example:

• Vehicle: Refrigerated truck (2–8°C)
• Front zone: 4.8°C
• Middle zone: 5.2°C
• Rear zone: 7.6°C
• Reference thermometers show ±0.2°C accuracy.
• Finding: Rear zone slightly warmer → calibration verified; airflow may be adjusted for uniformity.

Outcome:

• Confirms that the installed sensors accurately monitor temperature.
• Provides baseline data for operational and performance qualification.

8.2.  Performance Qualification (PQ) During Actual Transport Simulation

Purpose:

• To validate the vehicle’s performance under real transport conditions, including variations in ambient temperature, loading/unloading operations, and door openings.
• Ensures the system maintains target temperature throughout the entire transit cycle, not just in controlled static conditions.

Key Activities:

1. Simulated Transport:
   • Load the truck with representative product or thermal load simulators (e.g., water-filled containers, thermal packs).
   • Include variations in load distribution to mimic real scenarios.
2. Monitoring:
   • Use calibrated sensors and data loggers to record temperature throughout transit.
   • Record ambient conditions outside the vehicle.
3. Evaluation:
   • Compare temperature readings against predefined acceptance criteria (e.g., 2–8°C ±0.5°C for refrigerated).
   • Confirm alarms and data logging function correctly during transit events such as door opening or route changes.

Example:

• Vehicle: Frozen truck (–20°C)
• Simulation: 6-hour transit with door opening at 2 hours
• Data logger readings: –19.6°C to –20.4°C
• Result: All readings within ±1.5°C → Pass PQ

Outcome:

• Confirms vehicle performance under dynamic conditions.
• Demonstrates compliance with GDP requirements for product safety during actual transport.

8.3.  Periodic Requalification

Purpose:

• Ensures that the vehicle continues to meet operational and performance standards over time.
• Addresses potential drift in sensors, system wear, or environmental changes that could affect temperature control.

Frequency:

• Typically every 1–3 years, or as determined by risk assessment and regulatory requirements.
• Also required after modifications, repairs, or replacement of sensors/controllers.

Key Activities:

1. Repeat Calibration and Mapping:
   • Recalibrate all sensors and controllers.
   • Perform a temperature mapping study to verify OQ compliance.
2. Performance Validation:
   • Conduct a PQ simulation if required by risk assessment.
   • Evaluate historical performance data from temperature logs.
3. Document Review:
   • Update calibration certificates, validation reports, and vehicle qualification files.

Example:

• Truck ID: TRK-007
• Last PQ: 2022
• Requalification 2025:
  • Sensor calibration verified
  • OQ mapping shows temperature deviation within ±0.4°C
  • PQ simulation confirms performance under real conditions
• Result: Vehicle re-qualified and ready for GDP transport

Integration with Calibration

• Calibration supports qualification: Accurate sensors and controllers are the foundation for OQ and PQ studies.
• Qualification validates calibration: Mapping and PQ studies ensure that calibration results translate to reliable vehicle performance under operational conditions.
• Regulatory Compliance:
  • EU GDP Annex 15 and WHO GDP TRS 957 require that calibration and qualification activities be documented and traceable.
  • Calibration certificates and qualification reports serve as evidence during audits.

Summary Table of Related Qualification Activities

9. Common Deficiencies in Audits

Auditors from regulatory agencies (FDA, MHRA, EMA, Health Canada, ANVISA, WHO) often inspect transportation operations to ensure that temperature-sensitive products are handled according to GDP requirements. Calibration-related deficiencies are frequent findings and can lead to observations, warning letters, or corrective action requirements. Understanding these deficiencies helps companies prevent compliance issues.

9.1.  Calibration Overdue or Missing for Temperature Sensors

Issue:

• Vehicles are being used for product transport even though sensors, controllers, or data loggers have not been calibrated within the scheduled interval.

Regulatory Risk:

• EU GDP Annex 15 / WHO TRS 957: Requires calibration at defined intervals.
• FDA 21 CFR 211.68: Equipment must be routinely calibrated and inspected.

Example:

• Truck TRK-005 has sensors with last calibration on 01-Jan-2024, due 31-Dec-2024.
• The truck was used for shipping vaccines in Feb 2025 without recalibration.
• Audit finding: Overdue calibration → Non-compliance.

Mitigation:

• Maintain a Calibration Master List with due dates.
• Set automated reminders in the QMS to schedule calibration before expiration.

9.2.  Certificates Not Traceable to National Standards

Issue:

• Calibration certificates are available but cannot demonstrate traceability to recognized national or international standards (e.g., NIST, NRC, PTB).
• Certificates issued by non-accredited or unqualified vendors may not meet GDP expectations.

Regulatory Risk:

• ISO 17025 and GDP guidance require calibration to be traceable to certified reference standards.
• Certificates lacking traceability are considered invalid for regulatory compliance.

Example:

• Data logger calibration certificate shows “Calibration performed” but no reference to NIST or ISO 17025 accreditation.
• MHRA inspector notes: “Calibration not traceable to national standards.”

Mitigation:

• Use ISO 17025-accredited labs for calibration.
• Verify and archive traceable certificates for each sensor and device.

9.3.  Data Loggers Used in Transport Not Verified or Calibrated

Issue:

• Data loggers or integrated recording devices installed in trucks/trailers are assumed accurate without calibration verification.
• This is common for rented or third-party vehicles.

Regulatory Risk:

• WHO GDP Annex 5: Monitoring devices should be calibrated.
• FDA 21 CFR Part 11: Data integrity requires validated measurement devices.

Example:

• A rented refrigerated truck uses an onboard logger that has no calibration certificate.
• Upon inspection, the auditor finds that recorded temperatures could not be verified.

Mitigation:

• Always request calibration certificates from third-party vendors.
• Include verification step in SOP before releasing vehicles for shipments.

9.4.  Incorrect Calibration Range (Not Covering Operational Limits)

Issue:

• Sensors or controllers are calibrated only at one point or within a range narrower than the vehicle’s operational limits.
• Critical for vehicles that transport multiple product types with different temperature ranges.

Regulatory Risk:

• GDP requires calibration across the entire operational range to ensure accurate monitoring during excursions.

Example:

• Refrigerated truck 2–8°C
• Sensor calibrated only at 5°C → unknown accuracy at 2°C or 8°C.
• Auditor finds calibration insufficient → observation issued.

Mitigation:

• Calibrate sensors at multiple points:
  • For refrigerated: 2°C, 5°C, 8°C
  • For frozen: –20°C, –15°C, –10°C
  • For CRT: 15°C, 20°C, 25°C

9.5.  Missing Calibration Record for Replaced Sensors

Issue:

• After sensor replacement, no new calibration record or certificate is available.
• Sometimes old calibration certificates are incorrectly assumed valid.

Regulatory Risk:

• GDP, ISO 17025, and FDA require each instrument to be individually calibrated before use.

Example:

• Truck TRK-009 replaced rear zone sensor on 01-Mar-2025.
• During audit, the new sensor had no calibration record.
• Auditor observation: “Vehicle used without verified calibration → corrective action required.”

Mitigation:

• Update Calibration Master List immediately after sensor replacement.
• Perform calibration before vehicle is used for product transport.
• Maintain records in QMS and vehicle files.

Summary Table of Common Deficiencies

10. Best Practices

• Establish a calibration matrix for all GDP vehicles and devices.
• Use ISO 17025-accredited labs for external calibration.
• Integrate calibration schedules into Quality Management System (QMS).
• Review calibration certificates during vendor qualification.
• Implement preventive maintenance along with calibration.
• Include calibration verification during transport validation.

Contact Us

Good Distribution Practice (GDP) Trainings

GxP Cellators Consultants offers comprehensive Good Distribution Practice (GDP) training programs aligned with global regulatory standards, including Health Canada, EU GMP, US FDA, TGA, MCC, and MHRA. These programs are available both on-site and remotely to meet client needs across the life sciences industry.

The training covers key GDP elements such as:

• GDP principles and global regulatory expectations

• Qualification of trailers and transport vessels

• Temperature mapping requirements and study design

• Establishing GDP Quality Management Systems (QMS)

• Auditing and self-inspection practices

These sessions are designed to ensure safe, compliant, and efficient distribution of pharmaceutical products throughout the supply chain, focusing on practical, real-world applications of GDP requirements.

GxP Cellators Consultants are experts in GDP operations and provide full support for organizations seeking guidance, training, or compliance assistance in distribution activities as per international standards.