Understanding Clause 7.3.3 of ISO/IEC 17025:2017 – Retaining Sampling Records in Food Testing Labs

Clause 7.3.3 of ISO/IEC 17025:2017 emphasizes the importance of maintaining detailed and traceable records of sampling activities. In any accredited laboratory sampling is the foundation upon which all analytical results rest. If the sample is not collected, handled, and documented properly, even the most accurate analysis may be invalid or misleading.

This clause 7.3.3 mandates that every sampling event must be documented thoroughly, and the records should cover several key aspects to ensure transparency, traceability, and reproducibility of results.

The clause states that laboratories must retain sampling records that form part of the testing or calibration process. These records should include the following (where relevant):

a) Reference to the Sampling Method Used

The lab must document the exact sampling method used, whether it's an internal SOP, a national standard, or an international guideline. This provides clarity on the technique followed.

Example: A food testing lab may reference "FSSAI Manual on Milk Sampling, for raw milk sampling.

b) Date and Time of Sampling

Recording the precise date and time of sampling is essential to track sample stability and relevance of the test results, especially for perishable food products.

Example: Milk samples collected on 03/08/2025 at 10:30 AM must reflect this timestamp to validate freshness and compliance with holding time requirements.

c) Data to Identify and Describe the Sample

This includes sample code, product name, quantity, and batch number, helping to uniquely identify the sample among others.

Example: Sample Code: MILK-CHN-03AUG-01; Product: Pasteurized Milk; Quantity: 500 ml.

d) Identification of the Personnel Performing Sampling

The name or initials of the person who collected the sample ensures accountability and traceability.

Example: Sample collected by Mr. xxxxxxx, Senior Sampling Officer.

e) Identification of Equipment Used

Instruments used during sampling (e.g., scoops, sampling bottles, thermometers) must be recorded for quality tracking.

Example: Used Sterile Glass Sampling Bottle (ID: SGB-101) and Digital Thermometer (ID: DT-2025).

f) Environmental or Transport Conditions

Environmental conditions such as temperature, humidity, and transport conditions like refrigeration must be noted, especially for food samples sensitive to spoilage.

Example: Sample transported in an icebox at 4°C; ambient temperature during sampling: 32°C.

g) Diagrams or Location Identifiers

If location affects the result (like in environmental or field sampling), diagrams, sketches, or GPS coordinates should be included.

Example: Sampling point marked in factory layout map – “Raw Material Intake Bay – Point A”.

h) Deviations, Additions, or Exclusions

Any changes made to the sampling plan or method (and the reason why) must be documented.

Example: “Due to equipment failure, manual sampling performed instead of auto-sampler as per SOP No.xxxxxxxx.”

In food testing, sampling directly affects the validity of the test results. For example, testing the microbial load in dairy products is meaningful only if the sampling process has been carried out aseptically and under controlled conditions. Poor sampling documentation could lead to disputes with clients, invalid test results, or even loss of accreditation during audits.

Moreover, regulatory authorities such as FSSAI or export certification bodies often require a full sampling record to verify whether the tested product met compliance standards. Keeping complete records as per Clause 7.3.3 ensures the lab has a defensible and traceable process in place.

Best Practices to Follow

· Use pre-formatted sampling record sheets to ensure consistency.

· Train all personnel on how to document deviations properly.

· Maintain electronic or paper records securely with access control.

· Regularly review sampling records during internal audits.