ISO 17168-3:2025

Overview

ISO 17168-3:2025 - "Fine ceramics (advanced ceramics, advanced technical ceramics) - Test method for air-purification performance of semiconducting photocatalytic materials under indoor lighting environment - Part 3: Removal of toluene" specifies a laboratory test method to determine the air‑purification performance of photocatalytic materials for toluene removal under simulated indoor lighting. The standard covers semiconducting photocatalytic films and materials (commonly titanium dioxide and other ceramic semiconductors) in planar forms, honeycomb structures, and composites (including plastic or paper with ceramic microcrystals). It excludes powder or granular photocatalysts and is not intended for testing self‑cleaning, antifogging, antibacterial actions or water contaminant decomposition.

Key Topics and Requirements

• Test principle: Continuous flow photoreactor exposes a defined test piece to model air containing toluene under indoor-light illumination; removal is measured as the amount (µmol) and percent removed compared with dark (adsorption) conditions.
• Test pieces: Typical specimen size and reactor geometry are defined (e.g., ~99.0 mm × 49.0 mm test piece, ~5.0 mm air layer between sample and optical window).
• Apparatus: Requirements include a controlled test gas supply, humidifier, photoreactor, air‑tight optical window (quartz/borosilicate), indoor light source (cool white fluorescent per ISO 14605 or LED per ISO 24448), UV sharp cut‑off filter, and pollutant analytical system.
• Gas and flow control: Low adsorption materials for flow paths; flow rates managed within ±5% using mass flow controllers; standard toluene source typically 10–50 µl/l before dilution.
• Procedure and calculations: Pre‑treatment, dark adsorption test, illuminated photocatalytic test, and calculation of toluene removal quantity and removal percentage are specified.
• Limitations: Method targets air purification performance for indoor‑light‑active photocatalysts; not suitable for powders/granules or non‑air purification attributes.

Applications and Users

• Who uses it: Manufacturers of photocatalytic coatings and construction materials, independent testing laboratories (ISO/IEC 17025 conformity), R&D groups, product certification bodies, indoor air quality consultants, and specification writers.
• Practical uses:
  • Product development and optimization of indoor‑light‑active photocatalysts.
  • Quality control and batch verification for coatings, boards and honeycomb units.
  • Comparative performance data for marketing claims and regulatory or procurement specifications.
  • Research into VOC mitigation strategies and indoor air purification technologies.

Related Standards

• ISO 17168-1 - Removal of nitric oxide (companion test method)
• ISO 14605 - Light source for indoor photocatalyst testing
• ISO 24448 - LED light source specification for indoor tests
• ISO/IEC 17025 - Laboratory competence requirements
• Also cross‑references ISO 22197‑3 in development context.

Keywords: ISO 17168-3:2025, fine ceramics, semiconducting photocatalytic materials, toluene removal, indoor lighting, air‑purification performance, photocatalyst test method.