OOS Results - Very helpful Q&As published on the MHRA Website
Recommendation

17/18 November 2026
Heidelberg, Germany
Enhanced Approach using AQbD Principles
The FDA Guidance on OOS Results from 2006 is well known among the pharmaceutical industry. Guidance from the MHRA on how to handle out-of-specification results during laboratory analysis is - on the contrary - pretty unknown although an own webpage on the MHRA website is dedicated to the OOS topic.
This webpage lists 20 questions. Here are some of the topics dealt with:
- When is it acceptable to declare test results invalid?
- How many repeat tests should be conducted?
- Can OOS results and pass results be combined?
- How the certifying QP should handle unclear results
- Averaging of separate test results
- Retesting
- Re-sampling
- Outlier tests
To read all the 20 questions and answers please see "Out of specification (OOS) FAQs".
On the MHRA website, you can find a complete presentation on Out Of Specification Investigations. The presentation ends with the following statement: "Microbiological expectations will be provided at a later date."
At ECA's OOS Forum on 19/20 June 2012 in Prague, Di Morris, GMP Inspector for Medicines and Healthcare products, MHRA, UK, will give a presentation about "OOS in Microbiology". For the first time ever, she will present the requirements of a European authority regarding the GMP-compliant handling of OOS results in the microbiological laboratory.
Author:
Dr Günter Brendelberger
CONCEPT HEIDELBERG (a service provider entrusted by the ECA Foundation)
Related GMP News
02.11.2026FDA Warning Letter: When Test Procedures Allow Retesting Until an Acceptable Result is Obtained
21.10.2026EMA Updates Information Page on Bioequivalence Guidelines
21.10.2026BP Publishes new Draft Texts
21.10.2026FDA Identifies Critical Deficiencies in Analytical Testing and CGMP Oversight
07.10.2026Analytical Quality Group Developments May through August 2026
07.10.2026Two New FDA Warning Letters Put OOS Investigations in Focus


