What Is ISO/IEC 17025? How to Evaluate Accreditation Scope and Reliable Test Evidence

ISO / IEC 17025

Test data is an important form of evidence supporting corporate decisions on product safety, quality and compliance with environmental regulations. However, the reputation of a testing laboratory alone does not establish the technical reliability of every individual test result it produces.

ISO/IEC 17025 is the international standard that establishes requirements for the competence, impartiality and consistent operation of testing and calibration laboratories.

This article explains what ISO/IEC 17025 evaluates, how companies should examine a laboratory’s scope of accreditation, and how testing laboratories should be assessed in fields that continue to evolve—such as the Candidate List of substances of very high concern (SVHC) under the EU REACH Regulation.

EVIDENCE

1. Test Results Are “Evidence” Supporting Corporate Activities

In manufacturing, test results are more than analytical values.

They are used as a basis for corporate decisions in many situations, including compliance with chemical regulations such as the REACH Regulation and RoHS Directive, confirmation of product specifications, quality explanations to customers, research and development, failure analysis, communication with regulatory authorities and supply chain management.

When a company commissions a testing laboratory, what it ultimately needs is not simply the operation of analytical equipment.

It needs test data that can be reasonably explained to customers, business partners, regulatory authorities and internal quality assurance functions.

The important question is therefore not only whether a numerical result has been obtained, but under what conditions of competence, methodology, equipment control and quality management that result was produced.

ISO/IEC 17025 provides the international framework for evaluating whether a laboratory has the competence and systems required to consistently produce valid results under these conditions.

STANDARD

2. What Is ISO/IEC 17025?

The formal title of ISO/IEC 17025 is “General requirements for the competence of testing and calibration laboratories.”

It is an international standard jointly developed by ISO and IEC. The current edition is ISO/IEC 17025:2017.

The third edition was published in November 2017 and was reviewed and confirmed in 2023, meaning that the 2017 edition remains current.

ISO describes the standard as establishing requirements for the competence, impartiality and consistent operation of laboratories.

ISO/IEC 17025 is not a standard that simply confirms that a laboratory has equipment or documented procedures.

It evaluates whether competent personnel can use controlled equipment and facilities, apply valid methods, and appropriately review, record and report results.

Key Elements Covered by ISO/IEC 17025

The requirements of ISO/IEC 17025 cover general requirements relating to impartiality and confidentiality, structural requirements, resources, testing and calibration processes, and management systems.

From the perspective of a company selecting a testing laboratory, the following elements are particularly important.

Personnel Competence

Laboratories are required to define the education, training, skills, knowledge and experience necessary for personnel and to confirm their competence according to the activities they perform.

Even when the same analytical instrument is used, valid results cannot be expected without appropriate knowledge of sample preparation, measurement conditions, interfering substances and the evaluation of anomalous results.

Facilities and Environmental Conditions

Where temperature, humidity, vibration, dust, electromagnetic effects, cross-contamination or other environmental conditions can affect results, those conditions need to be appropriately controlled.

The measurement environment can directly influence results, particularly in fields such as trace analysis, dimensional measurement, microbiological testing and calibration.

Equipment Control

Measurement instruments and testing equipment need to have performance appropriate for their intended use and, where necessary, be calibrated, inspected, maintained and checked for performance.

Owning expensive or advanced analytical equipment is not the same as having the capability to consistently produce reliable results.

Metrological Traceability

Metrological traceability is the concept of relating a measurement result to an appropriate metrological reference through a documented, unbroken chain of calibrations.

A clearly established measurement reference is also important when comparing results obtained at different times or by different laboratories.

Selection, Verification and Validation of Methods

A laboratory needs to select methods appropriate for the intended purpose and confirm that it can properly perform those methods.

When a standardized or officially recognized method is introduced, the laboratory verifies that the method can be appropriately implemented using its own personnel, equipment and environment.

For laboratory-developed methods, non-standard methods or modified methods, validation is required to demonstrate that the method is suitable for its intended use.

Measurement Uncertainty

Quantitative measurement results contain sources of variation arising from factors such as equipment, reference materials, environmental conditions, sample preparation and personnel.

Particularly when a result is close to a regulatory or specification limit, measurement uncertainty and the decision rule applied can affect the determination of conformity or nonconformity.

Ensuring the Validity of Results

A laboratory does not simply perform measurements and issue reports. It also needs to continuously monitor the validity of its results.

Typical tools include reference materials, quality-control samples, blanks, replicate testing, proficiency testing and interlaboratory comparisons.

Impartiality and Confidentiality

A laboratory needs mechanisms to prevent test results from being improperly influenced by customers, sales functions, affiliated companies or other commercial interests.

It must also appropriately protect information received from customers, including samples, formulations, drawings, development information and test results.

COMPARISON

3. How Is ISO/IEC 17025 Different From ISO 9001?

ISO/IEC 17025 is sometimes confused with ISO 9001. Both are international standards related to quality, but their objectives and areas of evaluation are different.

ISO 9001 establishes requirements for organizations to establish, maintain and continually improve a quality management system.

ISO/IEC 17025 focuses on the technical competence and operation involved in producing testing and calibration results.

Therefore, even if a testing laboratory is certified to ISO 9001, that certification alone does not mean that its technical competence for individual test methods has been independently evaluated.

The two standards should not be viewed as competing alternatives. They support quality from different perspectives: one focuses on organization-wide quality management, while the other focuses on technical competence in testing and calibration.

ACCREDITATION

4. What Does “ISO/IEC 17025 Accredited” Actually Mean?

For ISO/IEC 17025, the appropriate concept is generally accreditation rather than certification.

Accreditation bodies use ISO/IEC 17025 as a basis for assessing testing and calibration laboratories and evaluating whether they are competent to perform specified testing or calibration activities.

An important distinction is that a laboratory’s statement that it “complies with ISO/IEC 17025” is not necessarily the same as formal accreditation by an independent accreditation body.

The term “compliant” may be used to indicate that a laboratory operates with reference to ISO/IEC 17025. That statement alone does not necessarily demonstrate that its technical competence has been independently assessed.

Where third-party assurance is required, companies should verify:

• Whether the laboratory holds formal accreditation
• Whether the accreditation is currently valid
• Whether the specific test being commissioned is included within the accredited scope

SCOPE

5. The Most Important Question Is the Scope of Accreditation

One of the most important points to check when evaluating ISO/IEC 17025 accreditation is the laboratory’s Scope of Accreditation.

Accreditation is not automatically granted to every activity performed by a laboratory.

Competence is recognized for defined testing or calibration activities, which may be specified according to methods, items, materials, measurement ranges and locations.

For example, even if a laboratory holds ISO/IEC 17025 accreditation, this does not necessarily mean that every ICP-MS analysis, GC-MS analysis, tensile test or weathering test it performs is within its accredited scope.

Even where the same type of analytical equipment is used, differences in the target material, measurand, test method or testing location can place an activity outside the accredited scope.

The question companies need to ask is therefore not merely:

“Is this laboratory ISO/IEC 17025 accredited?”

They also need to ask:

“Is the test we are commissioning actually within its accredited scope?”

Accredited and non-accredited activities may sometimes appear within the same quotation or test report.

Companies should therefore confirm the distinction when commissioning the work.

REGULATORY UPDATE

6. For REACH SVHC Testing, Also Look at How the Accreditation Scope Is Updated

In environmental regulatory testing, a laboratory cannot always be evaluated solely on the basis of its current scope of accreditation.

A representative example is the Candidate List of substances of very high concern (SVHC) under the EU REACH Regulation.

Under Article 59 of REACH, the European Chemicals Agency (ECHA) publishes and updates the Candidate List of substances that may ultimately become subject to authorisation.

Inclusion on the Candidate List can trigger obligations under provisions including Articles 7, 31 and 33 of REACH.

On February 4, 2026, two substances were added to the Candidate List. ECHA’s decision also specifies that the Candidate List was updated on that date.

However, the scope of an ISO/IEC 17025 accreditation does not automatically change on the same day that a new substance becomes subject to regulatory requirements.

To add a new substance or method to an accredited scope, a laboratory generally needs to introduce the method, complete the necessary verification or validation and quality-control preparations, and then undergo the assessment required to extend its accreditation scope.

A time gap can therefore arise between the date on which a substance is added for regulatory purposes and the date on which it is reflected in a laboratory’s accredited scope.

When evaluating a laboratory for long-term use in a regulatory field that continues to evolve, the following points can provide useful evidence.

A laboratory that has continuously expanded its accredited scope to cover previous additions may have an established system for responding to regulatory change.

However, a history of obtaining accreditation does not guarantee that future additions will also be accredited.

TICnology Japan considers the history of scope updates to be one of several useful indicators for evaluating a laboratory’s willingness and operational capability to respond to newly regulated items.

It is also important to note that the way an accreditation scope is expressed varies by accreditation scheme, testing field and test method.

In some cases, individual substances are listed. In others, accreditation may be expressed by analytical method or by a broader group of target substances.

Companies should therefore not judge the scope merely by whether a specific substance name appears in the document. The accreditation certificate and the detailed scope should be confirmed directly with the laboratory.

FIT FOR PURPOSE

7. Even Within the Accredited Scope, Confirm Whether the Test Is Fit for Purpose

ISO/IEC 17025 accreditation is important, but a test does not automatically become suitable for every purpose simply because it falls within an accredited scope.

Even when the same substance is being measured, the meaning and usability of the result can differ depending on conditions such as:

Example: Chromium Analysis

Even when a request is described simply as “chromium testing,” total chromium and hexavalent chromium are different measurands.

A total chromium result alone cannot be used to directly determine conformity with a requirement specifically addressing hexavalent chromium.

Example: PFAS Analysis

The information obtained and the intended use differ between methods that individually quantify specified PFAS, screening approaches based on parameters such as total organic fluorine, and methods designed to investigate a broader range of target substances.

Companies therefore need to confirm two separate questions:

These questions are related, but they are not the same.

CHECK POINTS

8. What Companies Should Check When Selecting a Testing Laboratory

When selecting a testing laboratory, companies should evaluate more than price or brand recognition.

At a minimum, the following points should be checked.

1. Formal Accreditation

Do not rely only on wording such as “ISO/IEC 17025 compliant.” Confirm whether the laboratory has received formal accreditation from an independent accreditation body.

2. Scope of Accreditation

Confirm that the relevant object, parameter, method, measurement range and testing location are included within the accredited scope.

3. Status of Scope Updates

In fields where regulations are continuously updated, check whether the laboratory has continued to expand its scope to cover previous additions.

If the latest item has not yet been accredited, it can be useful to confirm whether an extension is planned, the status of any assessment process, and how the test method has been verified.

4. Suitability of the Test Method

Confirm that the method is suitable for the relevant regulation, official method, customer specification or product standard.

5. Limit of Quantification and Measurement Range

Confirm that the test provides a limit of quantification and measurement range sufficient to evaluate the applicable regulatory limit or customer criterion.

6. Expertise in the Target Material

Appropriate sample preparation and management of interfering substances differ depending on whether the material is a resin, metal, coating, electronic component, food product or another matrix.

Experience and expertise with the target material can therefore be as important as experience with the analytical parameter itself.

7. Content of the Test Report

Confirm that the report contains the information required for the intended purpose, such as the test method, result, unit, limit of quantification, sample identification and a clear distinction between accredited and non-accredited activities where applicable.

8. Technical Consultation and Change Management

It is also important to assess whether the laboratory can provide appropriate explanations and recommendations when regulations, test standards or materials change.

Testing laboratories should therefore be evaluated comprehensively in terms of price, lead time, technical competence, accreditation scope, specialization and regulatory responsiveness.

TICNOLOGY JAPAN VIEW

CONCLUSION

Conclusion

ISO/IEC 17025 is an international standard addressing the competence, impartiality and consistent operation of testing and calibration laboratories.

Its scope goes far beyond laboratory equipment.

It addresses the overall system through which test results are produced, including personnel competence, test methods, facility conditions, metrological traceability, measurement uncertainty, monitoring of result validity, impartiality, confidentiality and records management.

However, accreditation is not automatically granted to every activity performed by an accredited laboratory.

Companies need to confirm whether the specific test they intend to commission is included within the laboratory’s accredited scope.

In areas such as the REACH Candidate List, where regulatory targets are periodically updated, there can also be a time gap between a regulatory addition and its inclusion within an accredited scope.

For this reason, it is important to look not only at whether the newest item appears in the current scope, but also at the laboratory’s record of responding to previous additions and its approach to future scope extensions.

The value of a test result is not determined by the name recognition of the testing organization alone.

Confirming these conditions is the first step toward selecting reliable test evidence.

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