Overview
ISO 19635:2016 - "Fine ceramics (advanced ceramics, advanced technical ceramics) - Test method for antialgal activity of semiconducting photocatalytic materials" defines a laboratory procedure to evaluate antialgal activity of flat photocatalytic materials under ultraviolet (UV) irradiation. The standard targets semiconducting photocatalytic coatings and substrates used in outdoor structures (for example, window panes, water-tank glasses, films, guardrails) and explicitly excludes powder, granular, or porous photocatalytic materials. ISO 19635 helps quantify how well a photocatalytic surface suppresses algae growth under simulated outdoor UV-A exposure.
Key topics and technical requirements
- Scope and materials: Applies to flat photocatalytic materials (coated, impregnated or blended) for building and road construction; powders, granules and porous materials are excluded.
- Test organism: Specifies the algae strain Chlorella vulgaris (NIES-227) as the biological indicator.
- Photoirradiation: Photoirradiation is defined in the standard as UV light in the 300 nm to 380 nm range. Test light sources include a 20 W black‑light blue (BLB) UV-A lamp with peak emission at 351 nm.
- Measurement method: Antialgal activity is determined using an absorbance‑based evaluation, including a three‑point absorbance spectrum method that compares treated vs. untreated materials after irradiation.
- Equipment & controls: Specifies laboratory controls and apparatus such as spectrophotometer (400–800 nm), UV radiometer calibrated around 351 nm, centrifuge, filter units (0.22 μm or 0.45 μm), and sterilization capability (hot‑air 160–180 °C; autoclave 121 °C).
- Test workflow: Standard describes steps for handling and cultivating algae, preparing test solutions, specimen cleaning and installation, inoculation, washing, photoirradiation, storage, and calculation/recording of results.
- Quality measures: Requires sterile handling, specific culture media and contamination control to ensure reproducible results.
Applications and who uses this standard
ISO 19635 is used by:
- Manufacturers of photocatalytic glass, films and coated building materials for product development and performance claims.
- Testing laboratories and quality control teams verifying antialgal performance under standardized UV conditions.
- Architects, specifiers and facility managers evaluating materials for urban façade conservation, water-tank windows, anti‑fouling applications, and infrastructure where algae growth is a concern.
- Researchers developing new semiconducting photocatalysts and coatings who require consistent comparative testing.
Practical benefits: enables objective comparison of photocatalytic antialgal performance, informs material selection for outdoor durability and hygiene, and supports R&D and product certification.
Related standards
- ISO 27447 - Test method for antibacterial activity of semiconducting photocatalytic materials (normative reference in ISO 19635).
- ISO/TC 206 - Technical committee responsible for fine ceramics standards.
For full test procedures, acceptance criteria and official text, obtain ISO 19635:2016 from ISO or your national standards body.