How to Choose an Accredited Laboratory: ISO/IEC 17025, GLP and What the Credentials Mean

Laboratory selection starts with the decision the data must support. A routine composition check, a disputed specification, an aquatic hazard study and a regulatory submission may require different quality systems and reporting detail. Asking whether a laboratory is accredited without explaining the intended use leaves the most important question unanswered.

Write a brief describing the product matrix, formulation identity, target analytes or endpoints, destination market and regulatory purpose. Include available safety information, relevant previous reports and any practical constraints affecting handling. A competent supplier should clarify uncertain requirements rather than promise that a general certificate is suitable for every authority.

Select the method and quality framework together. A scientifically sound method may still be outside the laboratory’s accredited scope. An accredited method may be unsuitable for your matrix. Regulatory study expectations may call for good laboratory practice rather than routine testing accreditation. Keep these distinctions visible when comparing quotations.

ISO/IEC 17025 specifies requirements for the competence, impartiality and consistent operation of testing and calibration laboratories. Accreditation evaluates the laboratory against these requirements for a defined scope. It addresses technical activities such as method validation or verification, equipment control, personnel competence, traceability where applicable and the assurance of valid results.

The accreditation certificate identifies the organisation and relevant locations, but its scope provides the practical detail. Read the listed tests, methods, materials or matrices and any ranges or limitations. A laboratory that holds accreditation for one type of analysis is not necessarily accredited for a cosmetic preservative challenge test, an environmental study or every analyte in a screening panel.

Some laboratories operate a flexible scope under conditions set by their accreditation body. In that case, request the controlled current list of activities covered within that scope and clarify how the proposed method fits. Do not interpret flexible scope as unrestricted permission to call any new service accredited.

Find the accreditation body’s official directory and search for the laboratory using its legal identity or accreditation reference. Check the current status, location and scope documents. Compare the directory record with the quotation rather than relying only on a logo or a certificate supplied in a sales presentation.

National accreditation bodies in Europe participate in cooperation through European cooperation for Accreditation. Its multilateral agreement supports recognition of accredited conformity assessment results within the relevant covered activities. Recognition depends on the body’s signatory status and scope of activity; it is not a promise that every report will satisfy every regulator or purchaser.

Record the verification source and retain the scope reviewed for the project. If the work takes place at another site, confirm that site’s coverage. Ask how suspension, scope changes or subcontracting would be communicated. Accreditation status can change, and a historical certificate does not establish current coverage.

The OECD Principles of Good Laboratory Practice concern the organisational process and conditions under which non clinical health and environmental safety studies are planned, performed, monitored, recorded, archived and reported. They focus on study integrity, defined responsibilities, quality assurance, raw data and traceability across the study lifecycle.

GLP compliance is monitored through national programmes using inspections and study audits. Ask for the facility’s current compliance information, the monitored study areas and any relevant limitations. A statement that staff work carefully is not equivalent to recognised GLP status. A method following an OECD test guideline is also not automatically a GLP study.

The OECD system for mutual acceptance of data supports acceptance of qualifying safety data generated under OECD test guidelines and GLP in participating countries. Its conditions and scope matter. Confirm the receiving authority’s requirements and the relevant national monitoring programme rather than treating the phrase mutual acceptance as a universal approval guarantee.

ISO 9001 concerns quality management systems. Certification can demonstrate that an organisation has a structured management framework, but it does not provide the same demonstration of method specific laboratory competence as ISO/IEC 17025 accreditation. It does not establish GLP compliance either.

A laboratory may hold several credentials for different purposes. Evaluate each against the proposed task rather than ranking logos. Routine analytical work might appropriately use an accredited method, while a regulatory toxicology study may require a GLP compliant facility and a suitable test guideline. Neither route removes the need to examine scientific relevance.

Distinguish accreditation, certification and regulatory recognition in procurement documents. Ask the supplier to identify which credential applies to each quoted activity and how this will appear in the final report. Clear wording at quotation stage prevents later disagreement about what quality status was purchased.

Define the report you need before authorising the work. A certificate with a result and a pass statement may be insufficient if the assessor needs a method description, study conditions, quality controls or raw data access. Agree whether conformity statements are required and what decision rule will be used.

The checklist below can be attached to a quotation request. Responses should identify uncertainties explicitly. Sample amount, reporting limits and retention conditions must be agreed for the actual project rather than copied from an unrelated product.

A method validated for a simple solvent may behave differently in a viscous emulsion, coloured extract or reactive mixture. Matrix effects can influence recovery, interference and the ability to quantify the target reliably. Ask how suitability is established and whether preparation changes are required. A familiar instrument name is not a complete method description.

The limit of detection and limit of quantification serve different purposes. A report saying not detected does not establish absolute absence. Clarify the reporting units, dilution basis and whether the result refers to the original sample or an extract. If the analytical capability cannot support the intended decision, refine the method before submitting material.

Measurement uncertainty is relevant to interpretation, particularly near a decision boundary. Where a laboratory states conformity with a specification, agree the decision rule and the treatment of uncertainty. Some biological studies require different approaches from routine chemical measurements. Request an explanation appropriate to the method rather than demanding a generic uncertainty number for every endpoint.

Be cautious when accreditation is advertised without a verifiable scope, when a supplier will not name the performing site, or when every result is described as regulatory approval. Other warning signs include unclear sample identity, missing method references, unexplained deviations and a quotation that excludes the report detail needed by the assessor.

Subcontracting is not inherently a problem, but it should be transparent. Clarify who reviews the report, who communicates deviations and whose accreditation or GLP status applies. Maintain traceable sample identification and handling records. Undocumented transfers can weaken otherwise competent technical work.

The product supplier or responsible person must still decide whether the results address the applicable obligation. A coordinator can reduce administrative and technical risk by matching the requirement to a method, verifying credentials, aligning sample logistics and reviewing report completeness. Coordination cannot change an unsuitable study into suitable evidence or guarantee acceptance by an authority.

Before approval, reconcile the quotation with the requested scope. List the formulation version, agreed methods, required quality status, report deliverables and escalation process for unexpected observations. Keep the record with the resulting studies so another reviewer can understand why the work was commissioned and how the conclusions were reached.

When results arrive, check identification, units, method coverage and deviations before using them in a submission or label review. Resolve ambiguities with the laboratory and regulatory reviewer. A well chosen supplier is valuable, but a controlled brief and a careful final review are what connect competence to usable evidence.