What to do when temperature mapping fails partially

Yes, if you document it correctly.

When mapping data shows some measurement positions outside acceptable ranges, the answer is typically not "the entire facility failed." Instead, use a risk-based zoning approach that identifies:

• Green zones: Areas with all measurements within the acceptable range (fit for immediate use)
• Yellow zones: Areas with intermediate excursions (suitable for less-sensitive products or with additional monitoring)
• Red zones: Areas consistently outside acceptable range (require corrective action before use)

This approach aligns with ICH Q9 (Quality Risk Management) principles and is supported by ISPE guidance on risk-based facility qualification. You are making a compliant, documented decision based on actual data, not gambling with a binary pass or fail verdict.

Also see: Understanding acceptance criteria in temperature mapping

Regulators want to see that you understand your facility's performance and have controls in place. A thoughtful non-binary conclusion demonstrates exactly that.

This approach shows:

1. Data-driven decision making: You are using actual measurement data, not guesswork
2. Risk management: You are applying ICH Q9 principles to facility qualification
3. Product protection: You are matching storage zones to product sensitivity
4. Ongoing control: You are implementing appropriate monitoring strategies

ISPE's Controlled Temperature Chamber Mapping and Monitoring supports risk-based zoning approaches in GxP facilities. WHO TRS 961 Annex 9 allows for "designated storage areas" based on mapping results.

A binary conclusion (pass or fail) may be simpler, but it does not reflect the reality of how facilities perform or how products can be safely stored. Auditors recognize this – they want to see intelligent risk management, not arbitrary rejection of functional space.

Traditional mapping reports conclude with a simple verdict: "The facility is deemed compliant" or "The facility failed qualification."

But what happens when 85% of your measurement positions pass, and 15% fail? Declaring the entire warehouse unusable wastes both money and time.

A non-binary conclusion documents performance by zone. Here is how to structure it:

Step 1: Visualize your zones on the floor plan

Mark each measurement position based on its performance during the study:

• Green: All data within 2-8°C (or your specified range)
• Yellow: Occasional excursions beyond range (document frequency and duration)
• Red: Consistent non-conformance

Use your actual facility floor plan with color-coded zones. This visual becomes part of your validation report and your operational SOPs.

Step 2: Write zone-specific conclusions

Do not write: "The facility failed temperature mapping."

Instead, write conclusions like this:

Areas marked green were deemed fit for purpose, with all data measured within the acceptable range.

Areas marked yellow experienced intermediate excursions to the acceptable range and should not be used for sensitive products with low thermal mass.

Areas marked red show temperatures outside the acceptable range and should not be used for products sensitive to temperatures outside the acceptable range.

This language comes directly from Mastering Temperature Mapping by Jakob Konradsen, Eupry's Chief Quality Officer. Jakob explains: "Rather than stating that the entire facility or equipment is not fit for purpose, a more valuable conclusion is to clearly mark areas that are fit for purpose, areas which are at risk, and areas that are not fit for purpose."

Step 3: Document your risk-based storage strategy

Your mapping report should include:

• Approved storage locations: Which zones can be used for which product types
• Monitoring requirements: Increased monitoring frequency in yellow zones
• Corrective actions: Timeline and responsibility for addressing red zones
• Product placement restrictions: Thermal mass requirements for yellow zones

This turns your "partial failure" into a compliant, operational facility with documented controls.

Scenario 1: Door proximity issues

Measurement positions near the loading dock doors experience excursions during simulated operations, but the rest of the warehouse passes.

Solution: Mark near-door areas as yellow zones. Use them for staging (short-term storage) rather than long-term inventory. Document that products in these zones move within 24 hours.

Scenario 2: HVAC capacity limitations

Your facility performs well at current inventory levels, but some high shelves near the ceiling show borderline temperatures during peak summer testing.

Solution: Mark upper levels as yellow zones. Restrict them to products with wider acceptable ranges (15-25°C ambient storage) or increase air circulation. Schedule a re-mapping study after implementing corrective actions.

Scenario 3: Seasonal performance differences

Winter mapping passes completely, but summer mapping shows some positions exceeding upper limits during peak afternoon temperatures.

Solution: Document summer-specific restrictions for affected zones. Implement increased monitoring during warm months. Consider seasonal mapping strategies when planning facility qualification timelines.

Also read: How to conduct summer temperature mapping in GxP

Your mapping report conclusion section should include:

1. Summary statement: "Mapping identified zones with varying levels of compliance."
2. Zone-by-zone performance data: Table showing minimum, maximum, and average temperatures per zone
3. Visual floor plan: Color-coded zones (include this as a controlled document for operations)
4. Risk assessment: Why each zone received its classification
5. Operational controls: How each zone will be monitored and used
6. CAPA plan: Timeline for addressing red zones (if corrective action is planned)

This documentation provides auditors with evidence that you:

• Conducted thorough analysis
• Made risk-based decisions
• Implemented appropriate controls
• Planned corrective actions where needed

Also see: Temperature mapping services for GxP

Green zones require standard monitoring at identified hot and cold spots.

Yellow zones need additional monitoring points to track excursion frequency. Continuous monitoring in these areas can eliminate uncertainty by providing real-time visibility into whether excursions are increasing or stable.

Red zones should not be used until corrective actions (HVAC adjustments, door seal repairs, insulation improvements) are completed and a follow-up mapping study confirms compliance.

Do not use zoned compliance if:

• Regulatory requirements prohibit it: Some markets require full facility compliance (check local GDP requirements)
• Your products cannot tolerate variation: All products require the same tight temperature range
• The failure is systemic: The HVAC system is undersized, and no zone consistently performs well
• You cannot monitor adequately: You lack the monitoring infrastructure to track yellow zones appropriately

In these cases, address the root cause before taking the facility into operation.

Tip! Eupry's validation team can help you identify whether system improvements or facility modifications are needed.

1. Update your SOPs: Reflect zone restrictions in storage procedures
2. Train your team: Ensure warehouse staff understand which zones are approved for which products
3. Implement zoned monitoring: Deploy additional sensors in yellow zones with automated monitoring solutions**
4. Schedule corrective actions: Create a timeline for addressing red zones
5. Plan follow-up studies: Determine when to re-map corrected areas

Need help implementing a non-binary compliance strategy? Book a consultation with Eupry's validation experts to review your mapping data and develop a compliant path forward.