HACCP food safety inspection: what the inspector checks and how to prepare

1. What is temperature mapping?

In effect, temperature mapping — also known as a temperature mapping study or warehouse study — involves measuring the temperature at multiple points simultaneously in a controlled environment. Additionally, this allows you to verify that the temperature everywhere in the space remains within the required specifications. In addition, a mapping identifies the warmest and coldest zones, known as hot spots and cold spots.

What does a mapping reveal?

First, all temperature variations in the space are made visible. In addition, the influences of external factors such as door movements, seasonal changes and HVAC failures are established. Furthermore, this gives a mapping a reliable picture of the actual conditions under which products are stored.

Why is it essential?

In other words, without temperature mapping, you simply do not know whether all products in the space are genuinely being stored within the required temperature range. A single sensor in the middle of a cold room does not give a representative picture of corners, doors or floor level. Moreover, temperature mapping solves this problem by providing a complete spatial picture.

2. When is temperature mapping required?

Temperature mapping is mandatory or strongly recommended in various sectors. Consequently, below we discuss per sector when a mapping is necessary.

Pharmaceutical (GDP)

Under the EU GDP guidelines (2013/C 343/01), temperature mapping is mandatory for all storage spaces where medicines are kept. Therefore, you carry out the mapping before commissioning and repeat it after significant modifications. Similarly, you also repeat the mapping when seasonal conditions change significantly.

Food industry (HACCP)

For HACCP applications, temperature mapping is not legally required, but it is a best practice. In particular, the NVWA asks questions during inspections about how you can demonstrate that cold rooms maintain the correct temperature. A completed mapping provides the best evidence for this.

Medical devices and laboratory environments

Under ISO 13485 and GMP guidelines, temperature mapping is required for storage spaces containing critical products. In addition, hospital pharmacies and blood banks structurally document storage conditions.

3. Preparation and planning

Good preparation is the foundation for a reliable mapping. Specifically, poor preparation leads to measurement results that are not representative of the actual situation.

Step 1: Establish the mapping protocol

First, you draw up a written protocol covering: the objective of the mapping, the space and locations to be measured, the number of sensors, the measurement duration, the acceptance criteria and the responsible persons. Indeed, without a protocol, the mapping is not audit-proof.

Step 2: Determine the number and location of sensors

As a rule of thumb: at least 1 sensor per 10 m² of floor area, with at least 1 sensor at the door, the HVAC outlet and in every corner. In addition, sensors must be placed at floor level, mid-level and ceiling level to measure vertical temperature differences. Notably, for GDP mapping, additional requirements apply based on room size.

Step 3: Calibrate the data loggers

All data loggers must then be calibrated with a valid ISO 17025 calibration certificate. Uncalibrated sensors simply render the mapping invalid for GDP or GMP compliance. Therefore, ensure that calibration certificates are available before the start of the measurement.

4. Carrying out the mapping

The mapping must take place under representative conditions. In practice, this means: normal operating conditions, including realistic door movements and normal occupancy of the space.

Measurement duration and conditions

The GDP guidelines do not prescribe a specific measurement duration. In practice, however, experts use a minimum of 24 hours as standard. As a result, for seasonally dependent spaces, however, a mapping in both summer and winter is required. However, this ensures the mapping covers the most extreme conditions.

Including worst-case scenarios

Worst-case scenarios must also be simulated during the mapping. In fact, consider door movements at peak times, a brief HVAC failure and opening of drawers or pallets. Evidently, this gives the mapping a realistic picture of the conditions under which the space actually operates.

Document everything continuously

In addition, all notable events during the measurement must be recorded in a logbook: time of door movements, outdoor ambient temperature, HVAC settings and any deviations. Accordingly, this logbook forms part of the final mapping report.

5. Analysis and reporting

After the measurement, the data is analysed and processed into a formal mapping report. Subsequently, this report is the evidence that the mapping was carried out correctly and serves as the basis for permanent sensor placement.

Contents of the mapping report

The report contains at minimum: the mapping protocol, calibration certificates of all data loggers used, a floor plan with all sensor positions, the complete measurement data per sensor, a statistical analysis (min, max, mean, standard deviation), an identification of hot and cold spots, conclusions and recommendations for sensor placement, and the signatures of responsible persons.

Assessing acceptance criteria

You then assess the results against the pre-established acceptance criteria. If the temperature at a measurement point falls outside the specifications, that is a finding requiring further investigation. In general, you then document the corrective measures before the space is commissioned or remains in use.

6. Permanent sensor placement after mapping

Based on the mapping results, the permanent sensors for continuous monitoring are placed. Overall, the principle here is: the hot spot (warmest zone) is the critical monitoring location, because temperature limit exceedances occur there first.

Minimum sensor coverage after mapping

For GDP compliance, at least the hot spot is continuously monitored. In addition, for larger spaces multiple sensors are placed to secure representative measurement points. Particularly, the sensor positions are recorded in the mapping documentation, so that at future inspections the relationship between mapping and monitoring can be demonstrated.

7. When do you repeat a mapping?

Temperature mapping is not a one-time activity. In fact, under GDP guidelines, there are multiple situations in which a repeat mapping is mandatory.

Mandatory repeat occasions

First, you carry out a repeat mapping after significant modifications to the space or the HVAC system. Second, GDP guidelines require seasonal mapping if the room temperature significantly follows outside temperatures. In addition, a repeat mapping is required after a serious temperature incident or a significant change in the storage or use of the space.

Recommended frequency

In addition to the mandatory occasions, most GDP consultants advise repeating mapping every 2 to 3 years as a periodic verification. For example, this keeps the mapping representative of the current situation and ensures changes to the building or installations are demonstrably taken into account.

8. Mapping for GDP vs. HACCP

Although the principles are similar, there are differences in approach and requirements between GDP mapping and HACCP mapping.

GDP mapping (pharmaceutical)

GDP mapping is formally required, fully documented and part of the validation system. For instance, the mapping report must be retained as part of the quality dossier and is retrievable during IGJ inspections. In addition, the mapping must have been carried out by or under the supervision of a qualified person (QPD).

HACCP mapping (food industry)

For HACCP, mapping is a best practice and supplementary evidence. Although not legally required, it is valued by the NVWA as part of the HACCP plan. A completed mapping demonstrates that you have systematically assessed cold storage conditions and that your monitoring points have been deliberately chosen.

9. Temperature mapping with Spotzone

Spotzone offers a complete temperature mapping service, including professional execution and audit-proof reporting. In addition, this means you do not need to focus on mapping alone, but also on the seamless transition to continuous monitoring.

What Spotzone offers

• Professional mapping study with calibrated data loggers
• Formal mapping report for GDP/GMP audits
• Recommendations for permanent sensor placement
• Optional integration with continuous monitoring via Spotzone sensors

After the mapping, we install the sensors at the optimal positions we have determined, so that your monitoring is immediately compliant. Likewise, more about our temperature mapping service or schedule a free demo.

Frequently asked questions about temperature mapping

Below you will find answers to the most frequently asked questions about temperature mapping. Nevertheless, this will prepare you well for audits and inspections.

Basic questions about temperature mapping

Questions about repeat mapping and reporting

Practical questions about execution