ISO/IEC 17025 laboratory accreditation vs product certification

A laboratory described as ISO/IEC 17025 accredited has been assessed for competence to perform specified testing or calibration activities within its accredited scope.

That is valuable evidence about the laboratory. It is not the same thing as certifying that a steel product complies with a material standard or purchase order.

What ISO/IEC 17025 is about

ISO/IEC 17025 sets requirements for the competence, impartiality and consistent operation of testing and calibration laboratories.

In steel work, an accredited laboratory may perform tests such as:

• chemical analysis;
• tensile testing;
• Charpy impact testing;
• hardness testing;
• metallographic examinations;
• corrosion or specialized mechanical tests.

The critical phrase is within the accredited scope. A laboratory can be accredited for some test methods but not others.

Therefore, do not stop at:

“The laboratory is ISO 17025 accredited.”

Check whether the specific test and method you require appear in the laboratory's current scope of accreditation.

What an accredited test report proves

A properly issued report from an accredited laboratory can provide strong confidence that the stated test was carried out under a competent laboratory system and according to the identified method.

But the report normally proves the test result for the submitted specimen or sample.

It does not by itself establish:

• where the sample came from;
• whether the sampled steel is the material delivered to the project;
• whether the product was manufactured using the required route;
• whether all production-stage requirements were met;
• whether the complete material standard has been satisfied;
• whether an EN 10204 3.1 or 3.2 certificate can legitimately be issued.

Sample identity and traceability are therefore just as important as laboratory competence.

Laboratory accreditation is not an MTC type

EN 10204 defines inspection-document types for metallic products. ISO/IEC 17025 concerns laboratory competence.

They answer different questions:

A 17025-accredited laboratory can support the evidence behind a certificate. It does not automatically turn a test report into an EN 10204 certificate.

See EN 10204 certificate types 2.1, 2.2, 3.1 and 3.2.

ISO/IEC 17025 vs ISO/IEC 17020

Another common confusion is between laboratory accreditation and inspection-body accreditation.

• ISO/IEC 17025 concerns testing and calibration laboratories.
• ISO/IEC 17020 concerns bodies performing inspection.

A third-party inspector may review manufacturing, witness testing, verify documents or perform other inspection activities under an inspection-body system. The laboratory performing the mechanical test may be a separate organization accredited to ISO/IEC 17025.

This distinction becomes relevant in EN 10204 3.1 vs 3.2 and in project ITPs with hold, witness and review points.

The phrase “ISO 17025 certificate” can be misleading

Buyers sometimes ask a supplier for an “ISO 17025 certificate” when they actually mean one of three things:

1. the laboratory's accreditation certificate;
2. the laboratory's detailed accredited scope;
3. an accredited laboratory test report for the steel.

These are different documents. For technical review, the scope is often more informative than the accreditation certificate alone.

Retesting stock material

Suppose stock steel was produced without a particular test and the purchaser agrees that additional testing may be performed.

Using an appropriately accredited laboratory is useful, but the procurement chain still needs to establish:

• the identity of the stock material;
• representative sampling;
• required specimen location/orientation;
• the correct test method;
• acceptance criteria;
• who must witness or approve the test;
• how the result will be documented;
• whether the governing specification permits retrospective testing for that requirement.

Accreditation solves only the laboratory-competence part of that problem.

Procurement takeaway

Use ISO/IEC 17025 accreditation as evidence that a laboratory is competent for specific testing activities — not as a substitute for product certification, traceability or compliance with the governing material specification.

For critical testing, ask for:

• accreditation body;
• current accreditation certificate;
• accredited scope covering the required method;
• test method and edition;
• sample identification;
• final laboratory report;
• clear linkage to the material/MTC and project requirement.

References and verification sources

• ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories
• ISO — ISO/IEC 17025 overview
• ISO/IEC 17020:2026 — Requirements for bodies performing inspection
• DIN EN 10204 — Metallic products — Types of inspection documents