ISO 22766:2020

Overview

ISO 22766:2020 - “Plastics - Determination of the degree of disintegration of plastic materials in marine habitats under real field conditions” - specifies field test methods to quantify disintegration (physical breakdown into fragments) of plastic materials when exposed in coastal marine habitats. The standard covers exposure in the sandy eulittoral (intertidal) and sandy sublittoral (seafloor) zones under natural conditions, defines apparatus and procedures, and prescribes endpoints and analysis techniques. It is a disintegration test (not a biodegradation test) and therefore cannot be used alone to support unqualified claims such as “biodegradable in marine environment.”

Key topics and technical requirements

• Test habitats: sandy eulittoral (tidal zone) and sandy sublittoral (seafloor); pelagic zones (surface/water column) are out of scope.
• Specimen form and size: films are preferred; typical test pieces are cut to 260 × 200 mm. Thickness measured per ISO 4591 or ISO 4593.
• Fixture and protection: specimens are fixed in non-degradable frames and protected on both sides with 2 mm × 2 mm plastic mesh to avoid fragment loss.
• Controls: a PHBH film (25–30 μm) as positive control and LDPE film (25–30 μm) as negative control.
• Exposure duration: typical evaluation at 3 years, though shorter/longer periods can be used if procedures are followed. Results must not be extrapolated beyond the measured exposure period.
• Endpoints and analysis:
  • Sieving procedure: residual material retained on a 2 mm sieve; disintegration reported as loss of total dry solids.
  • Image analysis (photogrammetry): area loss (%) by analysing photographs of recovered specimens.
• Limitations: not suitable for assessing disintegration due to heat or light; does not measure mineralization (CO2/O2) - therefore not a biodegradation assessment.
• Optional monitoring: environmental parameters and tests to demonstrate a biologically active marine environment.

Applications and who uses it

• Manufacturers and developers of biodegradable or compostable plastics and products intended for coastal use (e.g., fishing gear).
• Environmental testing laboratories and certification bodies (often operating to ISO/IEC 17025).
• Regulatory agencies, procurement teams, and NGOs assessing persistence of plastic litter in coastal zones.
• Researchers studying material durability, litter fate, and mitigation strategies for marine pollution.

Related standards

• ISO 22403 - intrinsic aerobic biodegradability in marine environment (biodegradation tests)
• ISO 15314 - degradation/durability of plastics floating or partially immersed in coastal waters
• ISO 4591 / ISO 4593 - film thickness determination
• ISO 3310-2, ISO 5667-3, ISO/IEC 17025, ASTM E11 - referenced normative documents

Keywords: ISO 22766:2020, disintegration test, marine habitats, plastics, eulittoral, sublittoral, PHBH, LDPE, photogrammetry, 2 mm mesh, field test.