ISO 23832:2021

Overview

ISO 23832:2021 - Plastics - Test methods for determination of degradation rate and disintegration degree of plastic materials exposed to marine environmental matrices under laboratory conditions specifies laboratory test methods to measure the physical degradation of plastic samples exposed to marine environmental matrices under aerobic conditions. The standard covers measurement of physical effects (mass loss, erosion, loss of tensile properties) and the degree of disintegration (fragmentation to particles < 2 mm). It is explicitly not intended for thermo-degradation or photo-degradation testing.

Key topics and technical requirements

• Three laboratory test methods:
  • Method A: Sand burial degradation test (samples buried in wet sandy marine sediment).
  • Method B: Sediment/seawater interface degradation test (samples at the sediment–water interface).
  • Method C: Seawater degradation test (samples exposed to seawater).
• Measured endpoints:
  • Mass loss, erosion rate, and tensile properties decay as indicators of degradation rate.
  • Degree of disintegration assessed by surface area loss and/or mass loss (fragments < 2 mm).
• Test materials and controls: provisions for test material, reference material and negative controls.
• Environmental matrix handling: sampling and preparation of sediment and seawater to recreate marine matrices at laboratory scale.
• Sample preparation and conditioning: acclimatisation, marking, protective nets, thickness and tensile measurements (linked to ISO tensile and thickness standards).
• Test setup and validity: incubation conditions, sampling times, replicates and criteria for test validity; flexible test design for screening or certification-level testing.
• Reporting: requirements for documenting methods, results and limitations; explicit guidance that numerical results reflect physical degradation propensity only.

Applications and who uses it

ISO 23832:2021 is designed for practical use by:

• Plastics manufacturers and product designers evaluating marine performance of materials and products (e.g., aquaculture gear, floating devices).
• Environmental testing laboratories conducting standardized marine degradation tests.
• R&D teams developing biodegradable or disintegrating plastics intended for marine use.
• Regulatory bodies, certification schemes and risk assessors needing standardized data on physical degradation in marine matrices.
• Waste management and marine litter researchers assessing fragmentation potential of plastic debris.

Note: Results from ISO 23832:2021 describe physical degradation propensity in controlled marine matrices and should not be used alone to claim “biodegradable in marine environment.”

Related standards

• ISO 527 series (tensile properties)
• ISO 4593 (film/sheet thickness)
• ASTM D638 (tensile properties of plastics)

Keywords: ISO 23832:2021, marine degradation, plastics test methods, degradation rate, disintegration, sand burial test, sediment seawater interface, seawater degradation test, mass loss, erosion rate, tensile properties.