ISO 20200 Determination of the Degree of Decomposition of Plastic Materials under Composting Conditions

The standard "ISO 20200 Plastics - Determination of the degree of degradation of plastic materials under composting conditions in a laboratory-scale test," developed by the International Organization for Standardization (ISO), describes a method for determining the degree of degradation of plastic materials when exposed to a laboratory-scale composting environment. However, this method is not applicable for determining the biodegradability of plastic materials under composting conditions. Further testing is required before compostability claims can be made.

The test method described in this standard determines the degree of degradation of plastic materials when exposed to a composting environment. This method does not require specialized bioreactors and is scaled for use in any general-purpose laboratory. It requires the use of standardized and homogeneous synthetic solid waste. Synthetic waste components are dry, clean, and safe products that can be stored in the laboratory without any odor or health concerns. Synthetic waste has a constant composition and does not contain undesirable plastic materials that could be mistakenly identified as test material at the end of the test and affect the final evaluation. The volume of synthetic waste to be composted and bioreactors is small (approximately 3 l). With limited test material, this method provides a simplified testing procedure.

For the purposes of this standard, the following terms and definitions apply:

• Compost: It is an organic soil conditioner obtained by the biological decomposition of a mixture consisting mainly of vegetables, fruits and garden residues, sometimes mixed with other organic matter and having limited mineral content.
• Compostability: The potential of a material to biodegrade and disintegrate in a defined and controlled composting process without leaving visible or toxic residues.
• Composting: Refers to the aerobic process designed to produce compost.
• Lab-scale composting: Refers to an aerobic process designed to produce compost on a lab scale under environmental conditions that simulate those experienced in an industrial compost pile.
• Fragmentation: The physical breaking down of a material into very small pieces.
• Dry mass: The mass of the sample measured after drying. Dry mass is expressed as a percentage of the mass of the wet sample.

The ISO 20200 standard is critical for assessing how plastics break down in controlled composting environments and contributing to the development of sustainable materials. This standard specifies a standardized procedure for measuring the physical breakdown of plastics into smaller pieces when exposed to a simulated composting environment.

The primary objective of the ISO 20200 standard is to determine the degree of degradation of plastic materials in a controlled composting environment. This is particularly important for assessing the environmental impact of plastics designed for composting, such as biodegradable or compostable plastics. By helping manufacturers and researchers understand how plastics behave under composting conditions, this standard helps design materials that comply with circular economy principles.

The ISO 20200 test method involves subjecting plastic samples to a laboratory-scale composting environment that mimics intensive aerobic composting. Key elements of the methodology include:

• Test setup: Plastic samples are placed in a controlled composting environment with specific temperature, humidity, and ventilation conditions to simulate real-world composting.
• Duration: Testing is usually conducted over a specific period of time during which the plastic is exposed to microbial activity and environmental factors that promote degradation.
• Measurement: The degree of fragmentation is assessed by measuring the physical breakdown of plastic into smaller pieces, typically using sieving techniques (referencing the ISO 3310-1 standard for test sieves). This standard specifies the percentage of material passing through a specific mesh size.
• Conditions: The test simulates the intensive aerobic composting process, providing consistent and repeatable results.

This method is accurate but limited by fragmentation, meaning it doesn't assess whether the plastic is fully biodegradable or compostable. Such claims require further testing.

The ISO 20200 standard is widely used in industries and research for the following purposes:

• Evaluating the performance of biodegradable plastics in composting systems.
• To support the development of environmentally friendly materials by providing data on degradation behavior.
• Ensuring compliance with environmental regulations and standards for plastic products.
• To inform labeling and certification processes for compostable plastics (in conjunction with other standards such as ISO 17088 or ASTM D6400).

For example, studies have applied the ISO 20200 standard to evaluate bio-derived polyurethane foam compositions to gain insight into degradation behavior using techniques such as thermogravimetric analysis and infrared spectroscopy.

The ISO 20200 standard plays a vital role in developing sustainable plastic solutions. By providing a reliable method for testing degradation, it helps:

• Promoting sustainability: Reduces environmental impact by encouraging the development of plastics that can be broken down effectively in composting systems.
• Standardizing testing: Increases confidence in material performance claims by ensuring consistent and comparable results across laboratories worldwide.
• Supporting the circular economy: Contributes to the design of materials that are compatible with waste management and recycling goals.

However, this standard does not address biodegradability, highlighting the need for complementary testing to fully validate compostability claims.

Each revision to this standard has increased the applicability and sensitivity of the standard by reflecting advances in composting technology and environmental science.

As a result, the ISO 20200 standard is a critical tool for assessing the degradation of plastics in composting environments and supporting the development of sustainable materials. While it does not assess biodegradability or compostability, it provides baseline data for manufacturers and researchers aiming to produce environmentally friendly plastics. By standardizing degradation tests, this standard contributes to global efforts to reduce plastic waste and promote a circular economy.

Our organization, which has been serving for many years and meticulously following global developments in science and technology, employs a team of experienced professionals and a broad infrastructure to conduct testing, measurement, and analysis in a wide range of areas for businesses across all sectors. In this context, we also provide testing services in accordance with the ISO 20200 Plastics - Determination of the degree of degradation of plastic materials under composting conditions in a laboratory-scale test.