Deviating Samples - EcoResponse

Guidance From Laboratory Committee of the European Co-operation for Accreditation

Following guidance from The Laboratory Committee of the European Co-operation for Accreditation (EA LC) to member accreditation bodies including the United Kingdom Accreditation Service (UKAS), focus on the handling of potentially deviating samples has been strengthened.

UKAS Issued Guidance & Policy Statement

UKAS have issued their own guidance and ‘Technical Policy Statement 63: UKAS Policy on Deviating Samples’ to assist laboratories. Compliance will be assessed during UKAS visits to all accredited laboratories.

What is a Deviating Sample?

• Date (and time) not provided for soils (and waters)
• Sample taken in wrong container
• Inappropriate headspace present (e.g. Volatiles)
• Preservation not undertaken
• Holding time exceeded on receipt
• Holding time exceeded in laboratory
• Deviation from method
• Quality control check failure and sample cannot be repeated
• Sampling dates must be provided for every sample to enable assessment against holding times for each test. The time of sampling is also required for waters for tests with very short holding times.

Deviating Sample Holding Time

Use of Correct Sampling Containers

• Correct sample containers are used for each test
• Any special sampling instructions are followed, e.g. fill container to eliminate headspace
• Sample preservation is carried out where required
• Sampling dates (and times for waters) are provided
• Analysis is scheduled within the specified holding times for each test

Should a self-sample kit be requested it is the customers responsibility to ensure samples are taken with the above guidelines in mind. Within all reports where a self sample was taken, deviating sample information will be included. Where a deviating sample is analysed, the test report shall clearly state the reason and that the validity of the test result may have been compromised.