SIST-TP CEN/TR 17825:2023

Overview

SIST-TP CEN/TR 17825:2023 is a technical report published by the European Committee for Standardization (CEN) that provides interpretation guidelines for water controls in accordance with EN 16615:2015. EN 16615:2015 specifies a quantitative test method for evaluating the bactericidal and yeasticidal activity of chemical disinfectants and antiseptics on non-porous surfaces using a mechanical wiping action (the 4-field test).

This technical report addresses challenges encountered by laboratories in validating water control data, especially when testing with gram-negative bacteria and yeasts. It aims to ensure data validity, support product claims, and facilitate clear communication with legal and regulatory bodies regarding disinfectant efficacy testing.

Key Topics

• Water Controls Interpretation
  The core objective of SIST-TP CEN/TR 17825:2023 is to define clear rules for interpreting water control results according to EN 16615:2015. The report proposes an adjustment in data evaluation criteria:

  • Original validity criterion: Average colony-forming units (cfu) in water control must be >10 cfu/25 cm² over fields 2-4.
  • Proposed modification: Consider fields 1-4 (including the initially contaminated field) for calculating average cfu to better reflect microbial presence and improve test validity.

• Challenges with Test Organisms
  Laboratories have reported difficulties obtaining valid water controls when testing with certain microorganisms such as Pseudomonas aeruginosa (gram-negative bacteria) and Candida albicans (yeasts). These organisms may be less recoverable in uninoculated water control fields, complicating interpretation.

• Regulatory and Legal Considerations
  Accurate water control interpretation is critical to avoid disputes with regulatory authorities concerning the validity of disinfectant efficacy data. This report helps standardize interpretations to support product claims reliably.

• Technical Committee and Scope
  CEN/TC 216, responsible for chemical disinfectants and antiseptics, prepared this report. It applies across European Union member states and aims to guide laboratories in harmonized data evaluation.

Applications

• Chemical Disinfectant Testing
  Laboratories performing efficacy testing of chemical disinfectants and antiseptics on surfaces use this guideline for consistent water control interpretation, making their data defensible in regulatory submission and quality assurance processes.

• Healthcare and Medical Facilities
  Validation of disinfectant efficacy supports infection control protocols in hospitals and clinics where hygiene and surface disinfection are critical.

• Regulatory Submissions
  Manufacturers submitting product claims for disinfectants rely on standardized evaluation criteria to meet European and international regulatory expectations related to bactericidal and yeasticidal activity.

• Laboratory Method Standardization
  Ensures comparability of results between different testing laboratories, especially when dealing with diverse microorganisms in disinfectant efficacy studies.

Related Standards

• EN 16615:2015
  The foundational standard that defines the 4-field test method for assessing disinfectant efficacy on non-porous surfaces using mechanical action. SIST-TP CEN/TR 17825:2023 provides interpretive support for water controls within this method.

• EN 14885
  Specifies the application of European standards for chemical disinfectants and antiseptics, including terminology and definitions referenced in SIST-TP CEN/TR 17825:2023.

Summary

SIST-TP CEN/TR 17825:2023 offers essential guidance on interpreting water controls in EN 16615:2015 disinfectant efficacy testing, particularly addressing variability with gram-negative bacteria and yeasts. By refining validity criteria, it helps laboratories produce credible, regulatory-compliant data supporting chemical disinfectant claims. This technical report is a valuable resource for manufacturers, testing labs, and regulatory bodies involved in surface disinfection product evaluation.

Keywords: SIST-TP CEN/TR 17825:2023, EN 16615:2015, chemical disinfectants, antiseptics, water controls interpretation, disinfectant efficacy testing, bactericidal activity, yeasticidal activity, standardization, regulatory compliance