ISO 17025 vs ISO 15189: Choosing the Right Quality Standard for Your Laboratory

ISO 17025 and ISO 15189 are two distinct international standards for laboratory quality and competence. ISO 17025 applies to testing and calibration laboratories across all sectors, while ISO 15189 applies specifically to medical laboratories that examine human specimens for diagnosis, monitoring, and treatment decisions. The choice between them depends on your laboratory's primary function, the nature of your testing, and the regulatory or accreditation expectations of your field. A diagnostic laboratory serving patient care should pursue ISO 15189, while a laboratory performing environmental, industrial, forensic, or research testing should pursue ISO 17025. Some laboratories maintain both accreditations when their work spans clinical and non-clinical testing.

Scope and Purpose of Each Standard

ISO 17025: General Requirements for Testing and Calibration Laboratories

ISO 17025 establishes requirements for the competence, impartiality, and consistent operation of laboratories that perform testing and calibration. The standard applies to any organization conducting laboratory activities, regardless of the number of personnel or the scope of testing. This includes laboratories in environmental monitoring, food safety, materials testing, forensic analysis, and industrial quality control.

The standard emphasizes method validation, measurement traceability, and estimation of measurement uncertainty. For example, a laboratory developing a method for trace metal analysis in wastewater must demonstrate that the method performs reliably across its intended concentration range. Full validation under ISO 17025 encompasses linearity, repeatability, intermediate precision, trueness, robustness, and measurement uncertainty, as demonstrated in a method development study for tin determination in industrial wastewater using inductively coupled plasma-optical emission spectrometry [15].

ISO 17025 requires laboratories to maintain a quality management system that covers document control, internal audits, corrective actions, and management review. The standard also mandates participation in proficiency testing programs and the use of validated or verified methods appropriate for the testing performed.

ISO 15189: Requirements for Quality and Competence in Medical Laboratories

ISO 15189 is the international standard specifically designed for medical laboratories. It incorporates the technical requirements of ISO 17025 while adding provisions for the unique aspects of clinical diagnostics, including pre-examination processes, post-examination processes, and direct interaction with patient care.

The 2022 revision of ISO 15189 introduced several structural changes. The revised standard aligns more closely with ISO 17025:2017, removes unintended prescription of specific procedures, focuses on patient interest and safety, minimizes new requirements, and improves clarity of text [12]. This alignment means that laboratories transitioning from ISO 15189:2012 to ISO 15189:2022 must adopt risk-based thinking and strengthen patient-centered requirements [10].

ISO 15189 covers the entire examination pathway, from test ordering and specimen collection through result reporting and interpretation. The standard addresses pre-analytical variables such as patient preparation, specimen identification, and transport conditions. It also addresses post-analytical factors including reference intervals, critical value reporting, and result communication to clinicians.

Key Differences Between ISO 17025 and ISO 15189

Primary Focus and Intended Use

The fundamental difference lies in the intended application of test results. ISO 17025 focuses on the technical competence of the laboratory to produce accurate and reliable test data for a defined purpose. ISO 15189 focuses on the laboratory's role in the total healthcare pathway, where results directly influence patient management decisions.

ISO 15189 includes requirements for the laboratory to define its relationship with clinical users, establish procedures for handling complaints from patients and clinicians, and ensure that examinations are appropriate for the clinical questions being asked. These requirements extend beyond the analytical phase into the pre-analytical and post-analytical phases of the total testing process.

Personnel Requirements

Both standards require laboratories to define the qualifications, training, and competencies of personnel. ISO 15189 places additional emphasis on the laboratory director's responsibilities and the need for personnel to understand the clinical implications of their work. The standard requires that staff receive training in patient safety, specimen handling, and the ethical aspects of diagnostic testing.

ISO 17025 focuses more narrowly on technical competence for the specific tests performed. Personnel must demonstrate proficiency in the methods they perform, but the standard does not require the same depth of clinical knowledge.

Method Validation and Verification

ISO 17025 requires laboratories to validate non-standard methods, laboratory-developed methods, and standard methods used outside their intended scope. The validation process must establish performance characteristics including accuracy, precision, specificity, detection limit, quantitation limit, linearity, and robustness.

ISO 15189 distinguishes between method validation and method verification. Validation is required for laboratory-developed tests and modified methods, while verification is required for standard methods that have been previously validated. The 2022 revision of ISO 15189 introduced new considerations for in-house diagnostic methods, particularly in relation to the European In Vitro Diagnostic Medical Devices Regulation (IVDR). Laboratories developing or modifying in-house diagnostic methods may face overlapping or partially conflicting requirements between ISO 15189:2022 accreditation and IVDR obligations [8].

Measurement Uncertainty

Both standards require laboratories to estimate measurement uncertainty for their quantitative results. ISO 17025 requires that laboratories identify all components of uncertainty and evaluate them using appropriate methods. ISO 15189 requires that measurement uncertainty be estimated for each measurement procedure and that the laboratory consider the clinical significance of uncertainty when reporting results.

Traceability and Reference Materials

ISO 17025 places strong emphasis on metrological traceability, requiring that measurement results be traceable to international standards or reference materials where available. ISO 15189 incorporates these traceability requirements but frames them within the context of clinical decision-making, requiring that the laboratory ensure the clinical usefulness of its measurement procedures.

Decision Framework for Selecting the Appropriate Standard

Laboratory Type and Testing Purpose

The first consideration is the nature of your laboratory's work. Medical laboratories that examine specimens derived from the human body for diagnosis, monitoring, or treatment decisions should pursue ISO 15189. This includes hospital laboratories, clinical reference laboratories, and specialized diagnostic laboratories such as those performing molecular testing for infectious diseases.

Laboratories that perform testing for regulatory compliance, product quality, environmental monitoring, or forensic purposes should pursue ISO 17025. This includes food testing laboratories, environmental laboratories, materials testing facilities, and forensic science laboratories.

Regulatory and Accreditation Requirements

Some jurisdictions mandate specific accreditation standards for certain types of testing. Clinical laboratories may be required by national regulations to hold ISO 15189 accreditation. Forensic laboratories may be required to hold ISO 17025 accreditation, particularly for DNA testing and other analytical procedures.

The relationship between ISO 15189 and ISO 17025 in forensic DNA practice is well established. Elimination DNA databases, which hold reference profiles from laboratory staff and crime-scene practitioners, interface with ISO 17025 accreditation requirements. These databases provide a critical quality assurance layer by enabling timely detection of contamination and preventing false investigative leads [7].

Scope of Testing Activities

Laboratories that perform both clinical and non-clinical testing may need to consider dual accreditation. A laboratory that performs clinical diagnostic testing and also conducts environmental monitoring or research testing may pursue both ISO 15189 and ISO 17025. The standards share many common elements, which can reduce the burden of maintaining dual accreditation.

The EC4 Essential Criteria for Quality Systems of Medical Laboratories were developed to serve as a guideline bridging ISO 15189 and ISO 17025 documents, recognizing that medical laboratories may need to address requirements from both standards [16].

At a Glance: ISO 17025 vs ISO 15189

Implementing a Quality Management System

Initial Gap Analysis

Before pursuing accreditation, conduct a gap analysis to compare your current practices against the requirements of the chosen standard. The gap analysis should cover all clauses of the standard, including organizational structure, document control, personnel competence, equipment maintenance, method validation, quality control, and reporting procedures.

A structured implementation approach begins with mentorship, followed by an initial gap analysis, and then systematic implementation of the quality management system [10]. Appoint a quality officer to oversee the process, secure leadership engagement, and provide staff training to establish core competencies.

Documentation and Record Keeping

Develop the required documentation including a quality manual, standard operating procedures, forms, and records. The documentation should reflect the actual practices of the laboratory and be accessible to all relevant personnel. Document control procedures must ensure that only current versions of documents are in use.

Records must demonstrate that the laboratory consistently follows its documented procedures. This includes records of equipment calibration and maintenance, reagent preparation and storage, quality control results, proficiency testing participation, and corrective actions taken.

Proficiency Testing and Internal Quality Control

Participate in proficiency testing programs relevant to your scope of testing. Proficiency testing provides an external assessment of your laboratory's performance against peer laboratories. Internal quality control involves the routine analysis of control materials to monitor the precision and accuracy of test methods.

Quality indicators should be established to monitor laboratory performance over time. These indicators may include rates of specimen rejection, turnaround times, critical value reporting, and customer complaints [10].

Method Validation and Verification

For ISO 17025, validate all non-standard methods and laboratory-developed methods before use. The validation must establish the performance characteristics of the method and confirm that it is fit for its intended purpose. For standard methods, verify that the laboratory can achieve the stated performance characteristics.

For ISO 15189, verify standard methods and validate laboratory-developed or modified methods. The 2022 revision emphasizes risk-based thinking in method selection and validation. Laboratories must consider the clinical risks associated with incorrect results and design their validation studies accordingly.

Transitioning Between Standard Versions

ISO 15189:2012 to ISO 15189:2022

The transition from ISO 15189:2012 to ISO 15189:2022 requires a second gap analysis that emphasizes risk-based thinking and alignment with patient-centered requirements [10]. The revised standard introduces new concepts including the consideration of risks and opportunities, the management of point-of-care testing activities, and enhanced requirements for information management.

Laboratories transitioning to the 2022 revision should review their existing quality management system against the new requirements and identify gaps. The transition process involves updating documentation, training personnel, and implementing new procedures where required.

The 2022 revision also addresses the relationship between ISO 15189 and ISO 17025 more explicitly. The alignment with ISO 17025:2017 means that laboratories familiar with ISO 17025 will find common structure and terminology in the revised ISO 15189 [12].

ISO 17025:2017 Considerations

ISO 17025:2017 introduced significant changes including a stronger emphasis on risk-based thinking, new requirements for impartiality and confidentiality, and updated requirements for method validation and measurement uncertainty. Laboratories transitioning to ISO 17025:2017 must review their procedures for risk assessment, ensure that impartiality is maintained, and update their method validation documentation.

Common Failure Patterns in Accreditation Implementation

Incomplete Documentation

A common failure is documentation that does not match actual laboratory practices. Documents may describe ideal procedures that staff do not follow in practice. This discrepancy is identified during internal audits and external assessments. Laboratories should ensure that documentation is practical, accurate, and regularly reviewed.

Insufficient Training Records

Accreditation bodies require evidence that personnel are competent to perform their assigned tasks. Laboratories often fail to maintain adequate training records, including initial training, ongoing competency assessment, and continuing education. Training records should document the specific methods each person is authorized to perform and the dates of competency assessments.

Inadequate Quality Control

Some laboratories fail to implement appropriate internal quality control procedures or do not document quality control results adequately. Quality control materials must be appropriate for the test method, and control results must be reviewed and acted upon according to defined procedures.

Poor Corrective Action Processes

When nonconformities are identified, laboratories must implement effective corrective actions that address the root cause of the problem. A common failure is implementing superficial corrective actions that do not prevent recurrence. The corrective action process should include root cause analysis, implementation of corrective measures, and verification of effectiveness.

Inconsistent Proficiency Testing

Laboratories may fail to participate in proficiency testing programs or may not investigate unsatisfactory proficiency testing results adequately. Proficiency testing is a critical component of demonstrating technical competence, and unsatisfactory results must be investigated and corrective actions implemented.

Records and Measurements for Accreditation

Essential Records to Maintain

Maintain records of all activities that affect the quality of test results. This includes equipment identification and calibration records, environmental conditions during testing, reagent preparation and expiration dates, sample receipt and handling, quality control results, and final test reports.

For ISO 15189, additional records are required for pre-analytical activities including specimen collection, transport, and storage conditions. Post-analytical records include result reporting, critical value notification, and communication with clinicians.

Quality Indicators and Monitoring

Establish quality indicators to monitor the performance of the quality management system. Common indicators include the number of nonconforming events, turnaround times, patient or customer complaints, and proficiency testing performance. Review these indicators regularly and use them to identify opportunities for improvement.

The Malawi-Liverpool Wellcome Research Programme experience demonstrates that establishing quality indicators and monitoring performance contributes to enhanced laboratory performance and improved documentation [10].

Biosafety and Personnel Protection

Laboratory Biosafety Considerations

Both ISO 17025 and ISO 15189 require laboratories to maintain a safe working environment. The World Health Organization Laboratory Biosafety Manual provides guidance on biosafety practices, facility design, and risk assessment for laboratories handling biological materials [2].

Laboratories must conduct risk assessments for all procedures and implement appropriate biosafety measures. This includes the use of personal protective equipment, biological safety cabinets where required, and safe handling and disposal of biological waste.

Quality Management System Handbook

The World Health Organization Laboratory Quality Management System Handbook provides comprehensive guidance for implementing quality management systems in laboratories [1]. This handbook covers all aspects of laboratory quality management, including organization, personnel, equipment, purchasing and inventory, process control, information management, documents and records, occurrence management, assessment, customer service, and facilities and safety.

Professional Escalation Criteria

When to Seek External Expertise

Laboratories should seek external expertise when they lack the internal capacity to implement specific requirements. This may include engaging consultants for method validation, measurement uncertainty estimation, or quality management system development.

Hybrid mentorship models, combining virtual and on-site mentorship, have proven effective for supporting laboratories in low-resource settings to achieve and maintain accreditation [17]. This approach can reduce costs while providing the expertise needed for successful accreditation.

When to Escalate Quality Issues

Quality issues that affect patient safety or the reliability of test results should be escalated to the laboratory director and appropriate external authorities. This includes critical value reporting failures, contamination events, and proficiency testing failures that indicate systemic problems.

For forensic laboratories, contamination events should trigger immediate investigation and may require notification of relevant authorities. Elimination DNA databases provide a mechanism for detecting contamination and preventing false investigative leads, but they require proper governance and auditing to be effective [7].

Limitations and Considerations

Resource Requirements

Accreditation requires significant resources including personnel time, financial investment, and ongoing commitment. Laboratories must allocate resources for documentation, training, quality control, proficiency testing, and internal audits. The cost of accreditation should be weighed against the benefits of demonstrating competence and meeting regulatory requirements.

Scope Reduction as a Strategy

For laboratories new to accreditation, reducing the initial accreditation scope can facilitate the process. A reduced number of test types in the first stage of seeking accreditation can aid the accreditation process, with the scope expanded in subsequent cycles [17].

Continuous Improvement

Accreditation is not a one-time achievement but requires ongoing commitment to quality improvement. Laboratories must conduct regular internal audits, participate in proficiency testing, review quality indicators, and implement corrective actions as needed. The effectiveness of quality systems depends on leadership commitment, workforce engagement, data infrastructure, and alignment with financing and regulation [9].

Frequently Asked Questions

What is the main difference between ISO 17025 and ISO 15189?

ISO 17025 applies to testing and calibration laboratories across all sectors, focusing on technical competence and reliable test results. ISO 15189 applies specifically to medical laboratories examining human specimens for patient care, adding requirements for pre-analytical and post-analytical processes, clinical appropriateness, and patient safety.

Can a laboratory hold both ISO 17025 and ISO 15189 accreditation?

Yes, a laboratory can hold both accreditations when its work spans clinical and non-clinical testing. The standards share many common elements, including quality management system requirements, method validation, and proficiency testing. Laboratories pursuing dual accreditation should review both standards to identify overlapping requirements and avoid duplication.

Which standard should a DNA testing laboratory pursue?

The choice depends on the purpose of the DNA testing. A clinical laboratory performing diagnostic DNA testing for patient care should pursue ISO 15189. A forensic laboratory performing DNA testing for criminal investigations should pursue ISO 17025. Some laboratories may need both accreditations if they perform both clinical and forensic testing.

How long does it take to achieve ISO 15189 accreditation?

The timeline varies depending on the laboratory's starting point, resources, and scope of accreditation. Implementation involves conducting a gap analysis, developing documentation, training personnel, implementing quality control procedures, and participating in proficiency testing. The process typically takes 12 to 24 months, though this can vary based on the laboratory's existing quality systems and available resources.

What is the relationship between ISO 15189 and the IVDR in Europe?

ISO 15189:2022 and the European In Vitro Diagnostic Medical Devices Regulation (IVDR) share the common objective of ensuring patient safety and diagnostic reliability, but they are grounded in different regulatory paradigms. ISO 15189 focuses on healthcare service quality and laboratory competence, while the IVDR introduces a device-centric lifecycle approach. Laboratories developing or modifying in-house diagnostic methods may face overlapping or partially conflicting requirements [8].

What are the key changes in ISO 15189:2022 compared to ISO 15189:2012?

The 2022 revision aligns more closely with ISO 17025:2017, removes unintended prescription of specific procedures, focuses on patient interest and safety, minimizes new requirements, and improves clarity of text [12]. The revision also emphasizes risk-based thinking and patient-centered requirements [10].

How does ISO 17025 address method validation?

ISO 17025 requires laboratories to validate non-standard methods, laboratory-developed methods, and standard methods used outside their intended scope. Validation must establish performance characteristics including accuracy, precision, specificity, detection limit, quantitation limit, linearity, and robustness. For example, a method for tin determination in wastewater was validated in full compliance with ISO 17025:2017, encompassing linearity, repeatability, intermediate precision, trueness, robustness, and measurement uncertainty [15].

What role does proficiency testing play in accreditation?

Proficiency testing provides an external assessment of laboratory performance against peer laboratories. Both ISO 17025 and ISO 15189 require participation in proficiency testing programs relevant to the laboratory's scope. Unsatisfactory proficiency testing results must be investigated and corrective actions implemented.

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• Biosafety Cabinet Types and Selection Guide for Microbiology Laboratories

References and Further Reading

• Laboratory Quality Management System Handbook. World Health Organization.
• Laboratory Biosafety Manual. World Health Organization.
• Assay Guidance Manual. National Center for Advancing Translational Sciences.
• Bioanalytical Method Validation Guidance. U.S. Food and Drug Administration.
• NCBI Literature Resources. National Center for Biotechnology Information.
• Interpol review of forensic science management, 2022-2025.. 2026.
• Toward a European standard for elimination DNA databases: Policy recommendations for harmonized minimum requirements.. 2026.
• The ISO 15189-IVDR dilemma in medical laboratory practice.. 2026.
• Healthcare Quality Systems: International Frameworks, Evaluation and Improvement Strategies.. 2026.
• Implementing and Transitioning a Laboratory Quality Management System from ISO 15189:2012 to ISO 15189:2022: Experience from the Malawi-Liverpool Wellcome Research Programme, Blantyre.. 2026.
• From Classroom to Cleanroom: Evaluating Industrial Field Visits as a Pedagogical Tool in Parenteral Pharmaceutical Manufacturing and Quality Control Education.. 2026.
• EN ISO 15189 revision: EFLM Committee Accreditation and ISO/CEN standards (C: A/ISO) analysis and general remarks on the changes. Clinical Chemistry and Laboratory Medicine, 2025.
• Accreditation of medical laboratories: What is new in ISO 15189:2022. Accreditation and Quality Assurance, 2024.
• Understanding the key differences between ISO 15189:2022 and ISO 15189:2012 for an improved medical laboratory quality of service. Romanian Journal of Laboratory Medicine, 2023.
• Chloride-assisted microwave-assisted digestion for reliable ICP-OES determination of tin in industrial wastewater: Method development and ISO 17025 validation.. Analytica Chimica Acta, 2026.
• Usefulness of EC4 Essential Criteria for Quality Systems of Medical Laboratories as Guideline to the ISO 15189 and ISO 17025 Documents. Clinical Chemistry and Laboratory Medicine, 2000.
• Hybrid Mentorship of Medical Laboratories to Achieve ISO 15189:2012 Accreditation in Malawi: The University of Maryland Malawi Experience. Global Health: Science and Practice Journal, 2024.

This article is educational and does not replace validated laboratory procedures, institutional biosafety review, manufacturer instructions, or professional interpretation.