It is quite common to hear the terms “validation” and “verification” used interchangeably amongst those of us who work in Food Safety and, up until the publication of ISO 16140-3, there was no globally accepted standard developed to help labs truly differentiate between the two. For context here, we define terms in the following way:
Validation is proof that the method “works.”
Verification is proof that the user can perform that method correctly.
Described another way using what I like to call the “airplane scenario”, the testing needed to determine that the airplane works is validation. Testing whether the flight crew can properly fly the aircraft is verification. Applying this to food safety, global air travel, or anything in between, the message is the same. Both terms and the work behind them are quite critical to the quality of a product or a service.
Background and Concept
The development of this standard is part of the larger ISO 16140 series of standards dedicated to validation and verification of methods. Whether these methods are alternative, rapid methods or cultural methods, the guidance covers a wide range of options for method developers, regulatory agencies, and end-users. To date, there have not been many protocols on verification available. There are only a few available online, and these are specific to government agencies or accreditation bodies. A standard created with an international view has been needed for some time.
Why does this matter? If you are an ISO 17025 accredited laboratory, it is a requirement to verify that you can properly perform each method under your accreditation. However, if you are not an ISO 17025-accredited laboratory, it is still important to conduct verification of the methods used in your laboratory.
This standard covers three types of validated methods: Qualitative, Quantitative, and Confirmation/Typing. That is, methods traditionally used for pathogen detection, indicator testing, or confirmation of presumptive results. If you are looking to onboard a new method or verify an existing one, Part 3 can be applied if it has been FULLY validated – meaning BOTH a comparative study AND an interlaboratory study have been conducted, compared to a reference method.
Methods that have been “fully validated”, are methods validated following the protocols:
Implementation
Two kinds of verification are distinguished in the standard, and you will need to perform BOTH, to complete method verification:
The standard includes excellent guidance on how to inoculate samples and how many replicates are appropriate for each product type. Clear acceptance criteria are also included.
Frequently Asked Questions
As a laboratory that is involved in Method Validation of alternative methods for both ISO and AOAC certification, we often receive questions about the proper way to approach verification and how it relates to validation. I have included here some Frequently Asked Questions that you and your team may have about the verification process or the standard itself:
Curious to learn more about Method Verification for your organization? Need assistance with the study design and organization? Contact Erin Crowley, Chief Scientific Officer at ecrowley@qlaboratories.com
If you would like to present this concept to your team or learn more, the ISO website has several presentations dedicated to this standard which are accessible here: https://committee.iso.org/sites/tc34sc9/home/essential-information/content-left-area/validation-of-methods/method-validation-and-method-ver.html