What is ISO 22404 – Plastic aerobic biodegradation about?
ISO 22404 specifies a laboratory test method to determine the degree and rate of aerobic biodegradation level of plastic materials. ISO 22404 can also be applied to other materials.
ISO 22404 is a simulation under laboratory conditions of the habitat found in a sandy tidal zone that, in marine science, is called the eulittoral zone. Biodegradation is determined by measuring the CO2 evolved by the plastic material when exposed to marine sediments sampled from a sandy tidal zone and kept wet with saltwater under laboratory conditions.
Note 1: The conditions described in ISO 22404 might not always correspond to the optimum conditions for the maximum degree of biodegradation to occur.
Note 2: Deviations from the test conditions described in ISO 22404 are justified in the test report.
Who is ISO 22404 – Plastic aerobic biodegradation for?
ISO 22404 on plastic aerobic biodegradation is useful for:
- The Plastics and polymers industry
- Plastic testing laboratories
- Design / innovation teams
- Environment control bodies
- Environmental / sustainability researchers and scientists
Why should you use ISO 22404 – Plastic aerobic biodegradation?
Products made with biodegradable plastics and other biodegradable materials are designed to
be recoverable by means of organic recycling in composting plants or in anaerobic digesters. The uncontrolled dispersion of biodegradable plastics in natural environments is not desirable. Test methods to measure the rate and level of biodegradation in natural environments (such as soil or the marine environment) are of interest to better characterize the behaviour of plastics in these very particular environments.
The characterization of biodegradable plastic materials can be enlarged by applying specific test methods that enable the quantitative assessment of biodegradation of plastics exposed to marine sediment and seawater. To carry out a proper product design, it is important to know whether a plastic material is inherently biodegradable when exposed to marine inocula.
ISO 22404 provides a test method for calculating and reporting biodegradation levels obtained under laboratory conditions using a marine inoculum. The marine inoculum is sediment sampled at the tidal zone. The plastic material is exposed to this environmental matrix and biodegradation is followed by measuring the evolved CO2.
ISO 22404 describes some terms and definitions related to biodegradation method, principles, test environments, and reagents. ISO 22404 walks you through the test procedure (which includes test material, reference material, preparation of the sediment, test setup, pre-conditioning phase, and then the measurement of carbon dioxide).
With findings based on ISO 22404, product designers would be in a position to work on materials that are more environmentally sustainable.