ISO 17168-1:2018

Overview

ISO 17168-1:2018 is an international test method for assessing the air-purification performance of semiconducting photocatalytic materials under an indoor lighting environment. Part 1 of this series covers the removal of nitric oxide (NO) by materials that contain or are coated with photocatalysts (typically semiconducting metal oxides such as titanium dioxide or other fine ceramics). The standard specifies a flow-type photoreactor test in which a test piece is continuously exposed to a model polluted air stream and indoor light to quantify NO removal and related reaction products.

Key topics and technical requirements

• Scope and applicability
  • Designed for flat sheets, boards, plates, honeycomb forms and plastic/paper composites containing ceramic microcrystals.
  • Not applicable to powders, granules or test pieces with excessive adsorbent where adsorption equilibrium cannot be reached.
  • Focused specifically on NO removal; not intended for evaluation of water contaminant decomposition, self‑cleaning, antifogging or antibacterial properties.
• Test apparatus
  • Test gas supply producing controlled NO concentration, temperature and humidity.
  • Flow-type photoreactor compatible with low-adsorption materials (e.g., glass, stainless steel, fluoropolymers).
  • Indoor light source and UV sharp cut-off filter to simulate indoor lighting spectra.
  • Pollutant analyzers (e.g., chemiluminescence for NO/NO2) and water analysis for eluents.
• Procedure highlights
  • Pretreatment of test piece, dark-condition adsorption tests, illuminated pollutant-removal tests and elution (washing) tests to assess regeneration.
  • Calculation methods for amounts of NO adsorbed, desorbed, formed (NO2), removed and net removal (NOx balance).
  • Reporting of test conditions, recovery, and material balance.
• Quality and traceability
  • Uses normative references (e.g., ISO 7996 for NO measurement) and laboratory competence expectations consistent with ISO/IEC 17025.

Applications and users

Who uses ISO 17168-1:2018?

• Manufacturers of photocatalytic building materials and coatings validating indoor-light performance.
• Independent testing and calibration laboratories performing comparative performance or quality control tests.
• Product developers and R&D groups optimizing indoor-light-active photocatalysts.
• Specifiers, architects and regulators assessing claims for air purification in indoor environments.

Practical uses:

• Verifying NO removal performance for market claims and product labels.
• Comparing formulations (e.g., TiO2-based ceramics) or surface treatments under standardized indoor-light conditions.
• Evaluating ease of regeneration via elution (washing) and long-term material balance.

Related standards

• ISO 22197-1 (UV-light photocatalytic testing - basis for this document)
• ISO 14605 (Light source for indoor testing)
• ISO 7996 (NO/NO2 measurement - chemiluminescence)
• ISO 10304-1, ISO 10523, ISO/IEC 17025

Keywords: ISO 17168-1:2018, photocatalytic materials, indoor-light-active photocatalyst, nitric oxide removal, air purification performance, fine ceramics, titanium dioxide, test method.