As the environmental impact of plastic is causing heightened concern, many biodegradable and compostable plastics have been offered as an alternative to conventional plastics, but the term “compostable” is commonly misapplied or misinterpreted. ISO 17088 addresses this by creating a standardized criterion for labeling plastics “compostable”. The standard determines whether the plastic and any associated contaminants will break down in industrial composting systems without disrupting the composting process or the compost produced.
ISO 17088 Test Method
The ISO 17088 guideline indicates the conditions under which disintegration in composting occurs, ultimate aerobic biodegradation occurs, and that compost does not adversely affect terrestrial organisms while controlling for constituents.
The tests include:
1. Composting Tests: ISO 17088 usually relies on composting tests, typically lab/industrial-scale composting tests, in order to imitate composting under real-world conditions.
2. Biodegradation Measurement: The biodegradation is quantified using one of many biodegradation methods that must be conducted to determine the rate and extent of biodegradation and chemical transformation by determining the loss of carbon dioxide (CO2), total oxygen demand, or by determining the mass of the plastic remaining.
3. Disintegration Analysis: Disintegration is evaluated either by visually examining the size and shape of the pieces of plastic during the composting process and composting cycle or by examining similarly done without subjective assessment – all are visual.
4. Heavy Metal Analysis: Compost is being evaluated for successive heavy metals (or its biologically solid included in the process), and the heavy metal concentrations from metal evaluations should not exceed regulatory limits.
5. Ecotoxicity Assessments: Some tests will subject the compost to ecotoxicity tests to evaluate the effects of the compost on plant growth, germination, or other biological functions in terms of the potential effects on the environment.
Tests Related to ISO 17088
This aligns with various other international standards, such as EN 13432 and ASTM D6400.
