When a peptide vendor or third-party testing service publishes a certificate of analysis (COA), the credibility of that document depends heavily on who produced it and how. ISO/IEC 17025 is the international standard that defines what a competent testing or calibration laboratory looks like. Accreditation against it means an independent body has audited the lab and found it meets those requirements. The current edition is ISO/IEC 17025:2017 (the third edition, published November 2017), which replaced the 2005 version.
What the Standard Actually Certifies
ISO/IEC 17025 is published jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). The 2017 revision is organised around general, structural, resource, process, and management-system requirements. It introduced explicit risk-based thinking and stronger requirements around impartiality and confidentiality. The standard still covers two areas. The first is how the lab runs its quality system: handling complaints, controlling documents, safeguarding impartiality. The second is technical capability, meaning the qualifications of staff, the calibration and maintenance of equipment, the validity of test methods, and how results are reported.
Accreditation is granted by a national accreditation body such as A2LA or NVLAP in the United States, UKAS in the United Kingdom, or DAkkS in Germany, after an on-site assessment. It is not permanent. Labs must pass periodic surveillance audits and full re-assessments to keep it. The scope of accreditation is also specific. A lab may be accredited for HPLC purity testing but not for mass spectrometry, so a COA is most meaningful when the test method listed falls within the lab's accredited scope.
Key things accreditation verifies include:
- Method validation — the lab has demonstrated its test procedures produce accurate, reproducible results
- Equipment traceability — instruments are calibrated against national or international measurement standards
- Staff competency — personnel are qualified for the tests they perform
- Measurement uncertainty — results include an honest estimate of how much the measured value may deviate from the true value
Where the accreditation body has signed an international mutual-recognition arrangement, the lab's reports also carry cross-border recognition. Historically this was the ILAC Mutual Recognition Arrangement (MRA). Following the merger of ILAC and the International Accreditation Forum (IAF) into the Global Accreditation Cooperation (GAC), operational from 1 January 2026, those arrangements are being consolidated into a single global MRA, according to ILAC's own announcements.
Why Some Labs Have It and Some Do Not
Accreditation is resource-intensive. The application process, on-site audits, proficiency testing participation, and ongoing documentation burden cost money and staff time. Larger contract labs serving pharmaceutical or food-safety clients typically pursue accreditation because their customers require it contractually or by regulation. Smaller labs, or those serving mainly research markets, may operate without it because their customers have not demanded it and the economics do not justify the investment.
This does not mean an unaccredited lab produces unreliable results. It means no independent third party has verified that it does. An accredited lab has passed an external audit. An unaccredited lab has not, so the user is relying on the lab's own representations about its methods and equipment. The distinction is relevant in the research-peptide space specifically. Several of the testing labs most widely used in that community are reported as not holding ISO/IEC 17025 accreditation for the peptide assays they run, which is one reason their results would not be accepted for formal regulatory submissions.
In the peptide research supply chain, the distinction matters because many products are sold for research use and not approved for human consumption. Regulatory oversight of these products is limited, so third-party lab testing is one of the few external checks available. A COA from an ISO/IEC 17025-accredited lab, where the tested method is within the lab's accredited scope, carries more evidentiary weight than one from a lab with no independent verification of its processes.
Quick Comparison
| Feature | ISO/IEC 17025 Accredited Lab | Non-Accredited Lab |
|---|---|---|
| Third-party audit of methods | Yes, on a defined schedule | No |
| Equipment traceability required | Yes | Not verified externally |
| Accreditation scope published | Yes, publicly searchable | N/A |
| Proficiency testing participation | Typically required | Not required |
| COA carries independent weight | Yes, within accredited scope | Relies on lab's own claims |
What to Look For on a COA
When reviewing a lab report, look for the accreditation body's logo and the accreditation number. That number can be cross-referenced on the accrediting body's public registry to confirm the lab's status and scope are current. If a COA lists a method, for example HPLC-UV or LC-MS/MS, but does not indicate whether that method falls within the lab's accredited scope, it is reasonable to ask the vendor or lab for clarification. Some labs perform both accredited and non-accredited tests and issue COAs for both, and the distinction is not always obvious at a glance.
Sources
- ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories (ISO catalogue)
- ISO — ISO/IEC 17025 overview page
- International Laboratory Accreditation Cooperation (ILAC) — MRA and signatories
- A2LA — accreditation body and public directory
- UKAS — United Kingdom Accreditation Service