When looking for a laboratory to perform a test, the first criteria are usually straightforward: Does the laboratory have the necessary equipment? Does it perform the required test? How much will it cost, and how long will it take? However, in projects where the test result will be used as the basis for a technical decision, conformity assessment, product approval, or submission to a customer or another authority, a more important question arises: How has the laboratory’s competence to perform this test been evaluated?
This is where the term Accredited Laboratory becomes important. Accreditation does not simply mean that a laboratory has purchased suitable equipment or claims that it is capable of performing a test; an Accreditation Body has evaluated the laboratory’s competence against relevant criteria and for a defined range of activities. For testing and calibration laboratories, ISO/IEC 17025 is the primary international standard for evaluating laboratory competence, impartiality, and consistent operation.
However, this definition includes one very important point: Accreditation does not mean that a laboratory is accredited for every test. A laboratory may be accredited while the specific test you require falls outside its Scope of Accreditation. Therefore, when selecting a laboratory, the professional question is not simply, “Does the laboratory have ISO/IEC 17025 accreditation?” It should be: Is the activity or test I require included within this laboratory’s Scope of Accreditation?
What Is an Accredited Laboratory?
An Accredited Laboratory is a laboratory whose competence to perform specified activities has been evaluated by an Accreditation Body, with a defined scope covering its accredited activities. For testing and calibration laboratories, ISO/IEC 17025 is the primary standard used for this assessment and covers areas such as personnel competence, equipment, methods, environmental conditions, metrological traceability, validity of results, impartiality, and the laboratory’s management system.
Accreditation should therefore not be viewed merely as a decorative certificate or a quality badge displayed beside a laboratory’s name. The main purpose of the process is to provide evidence of the laboratory’s competence for defined activities. This is what distinguishes accreditation from many general management-system assessments: the evaluation is not limited to the existence of procedures and documentation; the laboratory’s ability to perform the relevant activity is also part of the assessment.
For a more detailed explanation of ISO/IEC 17025 and topics such as personnel competence, equipment, metrological traceability, measurement uncertainty, and impartiality, see the article “What Is ISO/IEC 17025 and Why Is It Important for Testing Laboratories?”.
What Is a Non-Accredited Laboratory?
A laboratory that is not accredited for the activity in question, or a Non-Accredited Laboratory, is not necessarily a laboratory without suitable equipment, technical knowledge, or testing capability. An organization may have appropriate equipment and experienced personnel and may be capable of producing useful technical data, while its competence for the specific activity has not been evaluated and confirmed through the relevant accreditation process. This distinction should be considered when deciding how the result will be used.
For example, a product development team may use an internal test setup to compare two design concepts or conduct a preliminary test, and the resulting data may be entirely useful for an engineering decision at that stage. However, if the same result is intended for a process that requires a report from an Accredited Laboratory or an activity performed within a specified Scope of Accreditation, claimed technical capability or laboratory experience alone cannot replace the required accreditation.
The distinction between accredited and non-accredited laboratories should therefore not be reduced to “good laboratory versus bad laboratory.” The main questions are what the result will be used for, what level of confidence and acceptance is required, and whether the process receiving the result requires a specific form of accreditation.
What Is the Main Difference Between an Accredited and a Non-Accredited Laboratory?
The main difference is the existence of an independent and formal assessment of competence for a defined scope. In an Accredited Laboratory, an Accreditation Body has evaluated evidence of the laboratory’s capability against specified requirements, and the Scope of Accreditation identifies the activities for which that accreditation applies. In a laboratory without the relevant accreditation, no such independent confirmation exists for the activity in question, and the user of the result must determine what other evidence is sufficient to establish confidence in the laboratory’s capability.
| Accredited Laboratory | Laboratory Without the Relevant Accreditation |
|---|---|
| Its competence has been evaluated by an Accreditation Body | No such accreditation exists for the activity in question |
| Accredited activities are identified in the Scope of Accreditation | There is no relevant Scope of Accreditation |
| ISO/IEC 17025 is the primary basis for accreditation of testing and calibration laboratories | The organization may use other internal methods or systems |
| Results may be used in processes requiring accredited results, subject to the requirements of that process | Acceptance of the result depends on the purpose, customer, contract, or receiving authority |
| Maintaining accreditation requires continued maintenance and monitoring of laboratory competence | The organization’s capability must be evaluated through other appropriate evidence |
This table does not mean that every result produced by an Accredited Laboratory is automatically accepted for every application. The Scope of Accreditation, test method, reporting conditions, and requirements of the receiving authority must still be reviewed.
What Is the Scope of Accreditation and Why Is It More Important Than the Certificate Itself?
One of the most important factors to review when selecting a laboratory is the Scope of Accreditation. Accreditation based on ISO/IEC 17025 indicates that the laboratory’s competence has been evaluated and confirmed for specified activities, but the Scope of Accreditation identifies exactly what those activities are.
Suppose an automotive laboratory has the equipment and operational capability to perform dozens of tests, but only some of those tests are included within its Scope of Accreditation. In this situation, simply stating that “the laboratory is accredited” does not provide enough information to make a decision about a specific test. The standard number, method, or required activity should be compared with the laboratory’s Scope of Accreditation.
This distinction is also reflected on the TAT website. Information about TAT’s ISO/IEC 17025 Accreditation is provided on a dedicated page, while the TAT Table of Available Tests can be used to review available testing services. For a specific project, it is advisable to review not only the laboratory itself but also the status of the required test and the relevant accreditation scope.
Is Every Test Performed by an Accredited Laboratory an Accredited Test?
No. This is one of the most important misconceptions about accreditation. A laboratory may perform activities both within and outside its Scope of Accreditation. Therefore, simply having a test performed by an Accredited Laboratory does not automatically mean that the activity is covered by accreditation.
This distinction matters to the customer because the project may require a test result issued under accreditation. In such cases, before work begins, it should be confirmed that the required test is included within the Scope of Accreditation and that the report will be issued in accordance with the relevant requirements. If this is checked only after testing has been completed, the project team may discover that the report is not suitable for its intended purpose and that the test needs to be repeated.
For this reason, when requesting a quotation or test service, it is better to clearly specify the name and number of the standard, the required version, and the intended use of the result. Asking “Do you perform this test?” is not enough. If an accredited result is required, the more precise question is: “Is this test, under this standard and version, included within your Scope of Accreditation?”
What Is the Difference Between Accreditation and Certification?
These two terms are sometimes confused in everyday use. A laboratory may be described as having “an ISO 17025 certificate,” but in the technical language of conformity assessment, the relevant concept for laboratories is Accreditation. An Accreditation Body uses ISO/IEC 17025 as the basis for evaluating laboratory competence.
Certification is generally used to confirm conformity of a management system, product, process, or person with specified requirements, and its structure is not the same as laboratory accreditation. For example, having ISO 9001 certification does not, by itself, demonstrate that a laboratory has accredited competence to perform a particular technical test.
Therefore, when reviewing a laboratory’s credentials, it is important to determine what document has been issued, by which body, against which standard, and for what scope. Simply seeing the word ISO on a certificate is not sufficient to establish competence for a particular test.
What Does an Accreditation Body Do?
An Accreditation Body evaluates the competence of conformity assessment bodies, including laboratories, within the relevant framework. Laboratory accreditation is not limited to reviewing documentation; technical capability, personnel, equipment, methods, and the performance of relevant activities are also evaluated. After accreditation is granted, mechanisms are also in place to maintain and monitor accreditation status.
In Iran, the National Accreditation Center of Iran (NACI) operates as the national accreditation body. NACI is listed by ILAC as a Full Member and ILAC MRA Signatory, with a recognition scope that includes testing and calibration under ISO/IEC 17025. Taraz Azmoon TAT Laboratory also publishes information about its ISO/IEC 17025:2017 accreditation status on the TAT ISO page.
At the international level, the ILAC MRA provides a framework for the mutual recognition of conformity assessment results within the relevant scopes. Accreditation Bodies that are signatories to this arrangement undergo peer evaluation, and their recognition scopes are defined. This framework can facilitate international acceptance of results issued under accreditation, but the acceptance of a specific report must still be considered in relation to the requirements of the relevant authority, market, contract, and scope.
Is a Report from an Accredited Laboratory Accepted Everywhere?
Not necessarily. Accreditation and mechanisms such as the ILAC MRA can facilitate acceptance of results, but they should not be interpreted as a guarantee that every report will be accepted in every country and every process. The receiving authority may have specific requirements concerning the Accreditation Body, scope, test method, report format, or even the laboratories it accepts.
Therefore, if the result will be used for Type Approval, an international contract, a specific customer, or a regulatory authority, it is advisable to confirm the report acceptance requirements before testing begins. This helps avoid a situation in which the test has been performed correctly from a technical perspective but the report cannot be used for its intended purpose because of an administrative, contractual, or accreditation-related requirement.
One of the objectives of international accreditation frameworks is to facilitate acceptance of results and reduce barriers caused by repeated assessments, but these benefits operate within the applicable scopes and rules and do not replace the need to review the requirements of the intended destination.
Does a Result from a Non-Accredited Laboratory Mean It Cannot Be Trusted?
No. The quality and usability of a result depend on many factors, and the absence of accreditation does not by itself demonstrate that the data are incorrect. A research laboratory, an in-house vehicle manufacturer testing facility, or a development laboratory may have a high level of technical capability and generate highly valuable data for engineering development even when the specific activity is not covered by accreditation.
The difference is that, without accreditation, an independent assessment of competence for that specific scope is not available to the user. Depending on the importance of the decision, the customer may therefore need to review the method, equipment, calibration, personnel competence, metrological traceability, method validation, or other technical evidence independently.
For Pre-Tests and some development activities, an accredited test result may not be a project requirement. In contrast, when a test result is intended for submission to a specific authority, performing the activity within the laboratory’s Scope of Accreditation may be an explicit requirement. Therefore, laboratory selection should begin with the purpose of the test and how its result will be used.
When Is Using an Accredited Laboratory More Important?
The more formal or higher-risk the role of the test result in a project decision, the more important it becomes to review the laboratory’s accreditation status. If the report will be used for regulatory approval, conformity assessment, a customer contract, export purposes, or a decision with significant financial or safety implications, the requirements relating to laboratory competence should be identified before work begins.
In contrast, during early development stages, the objective may simply be to compare two designs, understand a Failure Mode, or perform an initial performance evaluation. In such cases, the project team may determine, based on the objective and risk, that testing under accreditation is not necessary. Even then, correct test methods, suitable equipment, and data quality remain important; what changes is the type of evidence required to establish confidence in the result.
Therefore, the right question is not “Should we always choose an Accredited Laboratory?” A more precise question is: “What decision or process will this test result support, and what requirements does that process impose regarding laboratory accreditation?”
Is Accreditation Required for a Pre-Test?
Not necessarily. A Pre-Test is generally performed for development purposes and to reduce the risk associated with the main test, and its result may be used solely for internal engineering decisions. If the project does not require an accredited result for such an activity, performing the Pre-Test outside the Scope of Accreditation may still provide useful engineering information.
However, even in a Pre-Test, differences between its conditions and those of the main test should be documented. If the project team intends to use the result to predict performance in the main test, the quality of the equipment, test setup, and measurement method becomes highly important. The further the Pre-Test conditions differ from those of the main test, the more cautiously the result should be generalized.
For this reason, accreditation and technical quality should not be treated as exactly the same concept. Accreditation provides independent evidence of competence within a defined scope, while the technical quality of a development activity should also be managed according to its intended purpose. For more information about the applications and limitations of preliminary testing, see “What Is a Pre-Test and How Is It Different from a Formal Test?”.
Does an Accredited Laboratory Guarantee That a Product Will Pass?
No. Accreditation concerns the laboratory’s competence to perform an activity, not the result that a product is expected to achieve. An Accredited Laboratory may test a specimen and find that the product does not meet the applicable requirement. The impartiality of laboratory activities also requires results to be reported according to the test data and criteria, rather than according to the outcome expected by the customer.
For this reason, statements such as “if the laboratory is accredited, the product will definitely pass” fundamentally misunderstand accreditation. The laboratory must be capable of performing the test correctly and producing a valid result; whether the product passes or fails depends on its performance against the applicable acceptance criteria.
This is another reason why product development services and formal testing should be distinguished by their purpose. Pre-Testing and Validation can help identify design weaknesses, but neither inherently guarantees that a product will pass a subsequent test.
What Should You Check When Selecting a Laboratory?
The first step is to clearly define the test and its purpose. The standard name, version, specimen type, and whether the result will be used for product development, Validation, Type Approval, CoP, a customer contract, or another purpose should all be established. You can then determine whether the laboratory has the equipment and capability to perform the activity and, where required, whether that specific test is included within its Scope of Accreditation.
Next, factors such as specimen acceptance conditions, Fixtures, test lead time, number of specimens, report type, deliverable data, and project-specific requirements should be reviewed. If the report must be accepted by another authority or customer, that party’s requirements should also be checked before the test is ordered.
For TAT, general information about the organization is available on the About TAT page, accreditation status is provided on the ISO/IEC 17025 page, and available testing services can be reviewed in the TAT Test Table. Keeping this information separate allows customers to evaluate the activity they actually need rather than relying on a general statement such as “an ISO 17025 laboratory.”
Laboratory Accreditation Alone Is Not Enough; Your Specific Test Must Be Checked
The most important point of this article can be summarized in one sentence: being an Accredited Laboratory is the starting point of the assessment, not the end of it. Accreditation is granted for a defined scope of activities, and the customer should determine how the required test, standard, and, where relevant, its version relate to the laboratory’s Scope of Accreditation.
On the other hand, an activity being outside the Scope of Accreditation does not by itself mean that the resulting data are worthless; the result may be entirely useful for product development or an internal project purpose. What determines which type of laboratory is appropriate is the intended use of the result and the requirements of the process in which that result will be used.
Therefore, when selecting a laboratory, instead of asking a general question such as “Do you have ISO 17025?”, a more precise question should be asked: “For this purpose, under what Scope of Accreditation and under what conditions will my test be performed according to this standard?” The answer provides a much clearer picture of whether the laboratory is suitable for the project.