ISO/IEC 17025 for Forensic Science Laboratories: Key Requirements

A forensic science laboratory's results end up in court. That is why accreditation matters more here than almost anywhere else: the laboratory must be able to show, years later, exactly what was done to an exhibit, by whom, with which validated method and with what confidence in the result.

In India, forensic laboratories are accredited by NABL against ISO/IEC 17025:2017, together with NABL's specific criteria for forensic science. This guide explains what the standard asks for in a forensic setting and how laboratories usually prepare.

Accreditation, not "ISO certification"

A forensic laboratory is not "ISO certified" in the way a factory is certified to ISO 9001. It is accredited for a defined scope — specific examinations, methods and ranges — after NABL assesses both the management system and the technical competence of the people doing the work. A laboratory can begin with a few disciplines (for example toxicology and chemistry) and extend its scope later.

Since October 2024 NABL accreditation runs on a four-year cycle with yearly on-site surveillance and reassessment every two years.

What the standard requires — in forensic terms

1. Impartiality and confidentiality (clause 4)

The laboratory must identify risks to impartiality — pressure from investigating agencies, workload targets, or analysts knowing more case context than they need — and show how those risks are managed. Case information and results must stay confidential.

2. Competent people (clause 6.2)

Each analyst needs defined competence requirements, documented training, supervised casework and formal authorisation for each examination they perform or report. Competence must be monitored, not just recorded once.

3. Facilities and contamination control (clause 6.3)

Separate areas for incompatible activities (for example pre- and post-amplification in DNA work), controlled access, and monitored environmental conditions where they affect results.

4. Equipment and metrological traceability (clauses 6.4–6.5)

Balances, pipettes, thermometers, chromatographs and other instruments need calibration traceable to national or international standards, plus intermediate checks between calibrations.

5. Handling of exhibits and chain of custody (clause 7.4)

This is where forensic laboratories are tested hardest. The laboratory needs procedures for receipt, unique identification, sealing and seal checks, storage, sub-sampling, return or disposal of exhibits — and records that show an unbroken chain of custody from receipt to report.

6. Method selection, verification and validation (clause 7.2)

Standard methods must be verified in your laboratory. In-house or modified methods — common in forensic toxicology, drug chemistry and digital forensics — must be validated for their intended use: selectivity, limits of detection, precision, accuracy and robustness, as relevant.

7. Measurement uncertainty (clause 7.6)

Where a quantitative result matters to the case — blood alcohol concentration, purity of a seized drug — the laboratory must estimate uncertainty and report it when it is relevant to the interpretation.

8. Ensuring the validity of results (clause 7.7)

Internal quality control, blind re-examination, and participation in proficiency testing or inter-laboratory comparisons. Where no formal PT scheme exists for a discipline, laboratories organise comparisons with other forensic laboratories.

9. Reporting (clause 7.8)

Reports must be clear and accurate, distinguish results from opinions and interpretations, and state any limitations. Statements of opinion need a documented basis.

10. Nonconforming work, complaints and control of data (clauses 7.9–7.11)

What happens when something goes wrong — a contaminated control, a broken seal, a software fault — and how electronic data and instrument software are protected.

11. Management system (clause 8)

Document control, records, risks and opportunities, corrective action, internal audits and management review.

International guidance for forensic units

Accreditation bodies use international guidance on applying ISO/IEC 17025 (and ISO/IEC 17020 for scene examination) across the forensic process. The long-standing ILAC-G19 guide, Modules in a Forensic Science Process, was replaced in 2026 by Global ACI-TECH-1-004(G) following the merger of ILAC and IAF into Global ACI. Laboratories preparing for assessment should use the current document.

A practical preparation route

1. Choose the first scope — disciplines, examinations and methods that are stable and frequently used
2. Gap assessment against ISO/IEC 17025:2017 and NABL's forensic criteria
3. Documentation that reflects real bench practice — exhibit handling, methods, QC, reporting
4. Validation and uncertainty studies for in-house methods
5. PT / inter-laboratory comparison plan for every examination in scope
6. Training and authorisation of analysts; ISO/IEC 17025 internal auditor training
7. Internal audit and management review, then application on the NABL portal

See the NABL accreditation process for laboratories for the application and assessment stages.

How Certsure can help

Certsure has supported quality-system projects with forensic science laboratories and police units in Uttar Pradesh — see our project gallery. We help forensic laboratories with gap assessment, documentation, validation planning, training and assessment readiness. Accreditation itself is granted only by NABL after its own assessment.

NABL accreditation support for testing and forensic laboratories →