ISO 22197-1:2016

Overview

ISO 22197-1:2016 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Test method for air‑purification performance of semiconducting photocatalytic materials - Part 1: Removal of nitric oxide provides a standardized laboratory method to measure the air‑purification performance of photocatalytic materials. The standard evaluates how materials that contain a photocatalyst (commonly semiconducting metal oxides such as titanium dioxide) remove nitric oxide (NO) from a model polluted air stream under UV illumination using a flow‑type photoreactor.

Key topics and technical requirements

• Scope and applicability: Applies to flat construction materials (sheets, boards, plates), honeycomb forms and composites that include ceramic microcrystals; excludes powder or granular photocatalysts. Not intended for evaluating self‑cleaning, antifogging, antibacterial, or water contaminant decomposition performance.
• Test principle: Continuous exposure of a test piece to model polluted air under UV light; performance is quantified from the net removal of nitrogen oxides (NOx = NO removed − NO formed). Dark‑condition tests distinguish simple adsorption/desorption from photocatalytic conversion.
• Apparatus and setup: Requires a test gas supply, photoreactor, UV light source, and pollutant analyser. Materials and components must be UV‑resistant and low adsorption (e.g., glass, stainless steel, fluoropolymers).
• Test gas and flow control: Uses diluted standard NO gas (typically 30–100 µl/l) mixed with purified/wet air; flow controllers and measurement on a wet‑gas basis are specified for accuracy.
• Test piece and dimensions: Typical flat test piece dimensions are given (e.g., ~99.0 mm × 49.0 mm, air layer thickness ~5.0 mm) and pretreatment, adsorption, removal and elution procedures are defined.
• Measurement and calculations: Includes procedures to quantify adsorbed, desorbed and chemically converted NO/NO2; an elution (washing) test assesses regeneration and nitrate/nitrite balance.

Practical applications

• Standardized evaluation of photocatalytic building materials (façades, cladding, paving) for air‑purification claims.
• Product development and quality control for manufacturers of photocatalytic ceramics and coatings.
• Comparative testing in research, certification and regulatory contexts to quantify NOx removal performance.
• Performance verification for urban air‑quality mitigation strategies using photocatalytic surfaces.

Who uses this standard

• Materials and coatings manufacturers
• Accredited testing laboratories (ISO/IEC 17025)
• Building product specifiers, certification bodies, and environmental regulators
• Researchers in photocatalysis and air‑quality mitigation

Related standards

Normative references cited include:

• ISO 4892‑1, ISO 4892‑3 (UV exposure methods)
• ISO 5725‑2 (measurement accuracy)
• ISO 6145‑7 (flow controllers)
• ISO 7996 (NOx chemiluminescence method)
• ISO 10304‑1, ISO 10523, ISO 80000‑1 and ISO/IEC 17025

Keywords: ISO 22197-1:2016, photocatalytic materials, air‑purification performance, nitric oxide removal, fine ceramics, titanium dioxide, photoreactor, NOx removal.