Why UKAS Accreditation Matters for Pool Testing

What UKAS is

UKAS — the United Kingdom Accreditation Service — is the sole national accreditation body recognised by the British Government. It was appointed under the Accreditation Regulations 2009. There is no other UK body with statutory authority to accredit testing laboratories.

UKAS itself does not test. It accredits the laboratories that do — assessing whether they meet the technical and management-system requirements of the international standard ISO/IEC 17025.

ISO/IEC 17025 — the testing-laboratory standard

ISO/IEC 17025 is the international standard for the competence of testing and calibration laboratories. For pool slip testing it covers:

• Technical requirements — staff competence, equipment calibration and traceability, test methods (BS EN 16165 Annex C), measurement uncertainty, environmental conditions, sample handling, validity of results
• Management requirements — quality management system, document control, internal audits, management review, complaints handling, corrective actions, impartiality

To achieve and maintain accreditation, a laboratory must demonstrate compliance with both domains, in detail, with documentary evidence — not just claim it.

How accreditation actually works

Initial accreditation requires a comprehensive on-site assessment by UKAS technical assessors. They examine documentation, observe pendulum testing being carried out, interview staff, review calibration records, and verify traceability to national measurement standards. The assessment typically takes several days and is followed by a written report identifying any non-conformities that must be resolved before accreditation is granted.

Once accredited, the laboratory is subject to annual surveillance assessments and full re-assessment every four years. Any significant change must be notified to UKAS.

'Scope of accreditation' — important for pools

UKAS accreditation is method-specific, not laboratory-wide. A lab might be accredited for pendulum testing on dry shod environments but not on barefoot pool environments; for surface roughness Rz testing or not. The lab's published scope of accreditation specifies exactly which methods are covered.

For pool operators, verifying that the provider's scope explicitly covers pendulum testing using Slider 55 is essential. A laboratory accredited only for Slider 96 testing is not appropriate for pool surround work, regardless of other claims of accreditation.

Where the difference shows in pool practice

• Insurance loss adjusters weight accredited reports more heavily when assessing pool claim liability. A non-accredited report on a contested pool claim is challenged on technical-competence grounds before its substantive findings are even discussed.
• HSE inspections — where a pool operator is inspected following an incident, accredited testing in the safety file is positively received documentary evidence.
• Pre-handover sign-off — main contractors and clients increasingly require accredited testing for BS 8204 and pool specification compliance.
• Local authority and NHS pool tenders — frequently specify accredited testing as a tender requirement.
• Civil litigation — opposing experts will challenge non-accredited methodology under CPR Part 35 cross-examination.
• Repeat testing under accredited methodology is comparable across visits; non-accredited testing is not, because methodology and traceability cannot be verified between visits.

Verifying a provider's accreditation

UKAS publishes a searchable directory of accredited laboratories at ukas.com. Any provider claiming UKAS accreditation can be verified there, including the specific scope of methods covered. If a provider's claim does not appear on the UKAS register, the claim is not valid. For pool operators commissioning testing for the first time, this verification is a 30-second protective step worth taking.