ISO 20200:2023

Overview

ISO 20200:2023 - "Plastics - Determination of the degree of disintegration of plastic materials under composting conditions in a laboratory‑scale test" specifies a laboratory-scale method to measure how much a plastic material physically disintegrates when exposed to a controlled composting environment. This standard determines disintegration only; it does not measure biodegradability and additional tests are required to claim compostability.

Key Topics and Requirements

• Scope: Laboratory-scale composting simulation to quantify physical breakdown (disintegration) of plastic test pieces. Not applicable for proving biodegradability or compostability claims.
• Test matrix: Uses a defined synthetic solid waste inoculated with mature compost. Synthetic waste must be homogeneous, stored safely and adjusted to 55% water content and a C:N ratio of 20:1 to 40:1.
• Synthetic waste composition (dry mass %):
  • Sawdust 40%
  • Rabbit-feed (alfalfa-based) 30%
  • Ripe compost 10%
  • Corn starch 10%
  • Sucrose 5%
  • Cornseed oil 4%
  • Urea 1%
• Composting reactor: Preferred box ~30 × 20 × 10 cm (volume ≈ 3 L) with gas exchange openings; other containers 5–20 L allowed if aerobic conditions are maintained.
• Incubation modes:
  • Type 1: Constant thermophilic incubation at 58 °C for 84 days.
  • Type 2: Two-stage incubation - 58 °C for 56 days followed by 45 °C until day 84 (simulates a declining temperature profile).
  • Mesophilic incubation optional where applicable.
• Sample preparation: Cut test pieces to defined areas based on thickness; dry under vacuum at (40 ± 2) °C to constant mass prior to testing.
• Endpoint & measurement: After composting, sieve final matrix through a 2 mm sieve to recover non-disintegrated residues. Degree of disintegration is calculated from the mass reduction of test pieces.
• Monitoring & diagnostics: Odour, visual appearance, chemical analyses, dry mass and volatile solids are documented to validate the test.

Applications and Who Uses It

• Material manufacturers testing candidate formulations for physical disintegration in composting environments.
• Independent testing laboratories performing standardized screening before biodegradability/compostability assessment.
• R&D teams comparing disintegration performance of different plastics or additives.
• Regulatory bodies and procurement teams that require standardized lab evidence of disintegration behavior.
• Waste management researchers evaluating how consumer plastics fragment in composting systems.

Related Standards

• ISO 17088 (compostability specifications and labeling) - for claiming compostability
• ISO 16929 (related temperature profiles) - referenced for incubation comparability
• ISO 3310‑1 (test sieve requirements) - sieving specifications
• ISO 14855‑2, ISO 18606 - related terms and test concepts

ISO 20200:2023 is an essential screening tool to quantify physical disintegration under controlled composting conditions and to inform follow‑up biodegradability and compostability testing.