ISO 17025 Clause 5.4.2 – Selection of Methods

Q: We are working with the Mexican Accreditation Entity (EMA) for certification to ISO/IEC 17025:2005 General requirements for the competence of testing and calibration laboratories. Clause 5.4.2 states: The laboratory shall confirm that it can properly operate standard methods before introducing the tests or calibrations.

We are a testing laboratory and work with Method 21 – Determination of Volatile Organic Compound, EPA 40 CFR Ch.1 ( 01/07/04 Edition ) Test: Monitoring of Fugitive Emissions.

The question is: What would be the best way or a way to confirm the method? Or, to put it another way, how can we satisfy the requirements in clause 5.4.2 ?

A: The questioner is referring to clause 5.4.2 from ISO/IEC 17025:2005. An excerpt of this clause is below. Please refer to ISO/IEC 17025:2005 for the full clause.

5.4.2 Selection of methods

“…Methods published in international, regional or national standards shall preferably be used….. Laboratory-developed methods or methods adopted by the laboratory may also be used if they are appropriate for the intended use and if they are validated…. The customer shall be informed as to the method chosen. The laboratory shall confirm that it can properly operate standard methods before introducing the tests or calibrations.…”

Since the questioner is using the published methods, there is no need for validation of the method unless the method is modified.

However, the proficiency of being able to apply the published method needs to be demonstrated. This can be demonstrated by a documented Gage R & R study, Analysis of Variance (ANOVA) or Design of Experiments (DOE) study as appropriate to show proficiency in being able to utilize the test method properly.

The results from these studies may also be used to estimate the uncertainty of measurement for the tests. Reporting uncertainty of measurement with both test and calibration results is a requirement in ISO/IEC 17025:2005. The ILAC P14 document is a good guidance document on reporting uncertainty.

Dilip A Shah
President, E = mc3 Solutions
Chair, ASQ Measurement Quality Division (2012-2013)
Secretary and Member of the A2LA Board of Directors (2006-2014)
Medina, Ohio

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