In light of the guidance provided by the Laboratory Committee of the European co-operation for Accreditation (EA), UKAS would like to re-iterate its position relating to the handling of deviating samples by accredited laboratories and the disclaimers required in test reports or certificates.
Deviating samples are samples which are not (correctly) preserved, for example they may have exceeded their maximum preservation time, lack the date and time of sampling, are not cooled, have inappropriate headspace and so on. As a result, deviating samples may jeopardise the validity of the reported test result.
Accreditation bodies which are members of EA have previously observed that laboratories, in particular those operating in highly competitive markets, were not critical about the samples they receive. Large numbers of deviating samples were accepted, analysed and test reports were issued without any remark. The EA Laboratory Committee members concluded that such practice does not meet the requirements of ISO17025 and is not in the interest of the laboratories, their customers or other end-users of the test result(s). Guidance was provided as detailed below;
- Upon receipt of each sample, a competent laboratory shall assess whether the sample is suitable with regard to the requested test(s);
- When the sample is deviating, a competent laboratory shall contact the customer for further instructions;
- When the customer wants the deviating sample to be analysed, a competent laboratory shall include a disclaimer in the report, clearly stating that the sample was deviating and that, as a result, the test result(s) may be invalid;
UKAS, as an accreditation body, will be strengthening its focus on handling of deviating samples and the inclusion of disclaimers in the corresponding test reports during assessment visits to laboratories.
The EA Laboratory Committee and the EA peer evaluation system will also ensure the continuation of this focus as deviating samples play a role in many fields: such as environment, food, medicine and agriculture.