What is the difference between ASTM D6954 and ASTM D5988 standards
ASTM D6954 and ASTM D5988 are both standards used to test the biodegradability of plastics, but they differ in their specific applications. ASTM D6954 is specifically designed for testing oxo-biodegradable plastics, while ASTM D5988 is designed for testing the aerobic biodegradation of plastic materials in soil.
Here are some of the differences between the two standards:
ASTM D6954
ASTM D6954 uses established ASTM International standards in three tiers for accelerating and measuring the loss in properties and molecular weight by both thermal and photooxidation processes and other abiotic processes (Tier 1), measuring biodegradation (Tier 2), and assessing the ecological impact of the products from these processes (Tier 3).
- Covers plastics designed to degrade by a combination of oxidation and biodegradation (oxo-biodegradable plastics)
- Has a two-tier approach:
1) Measures abiotic oxidation by heat or UV exposure until molecular weight drops below 5,000 Daltons
2) Measures biodegradation of the oxidized residues in soil, compost or landfill environments - Requires 60% conversion to CO2 for homopolymers and 90% for heteropolymers to pass
- Includes analysis of residual plastics for toxicity and gel/cross-link formation
ASTM D5988
ASTM D5988 provides a method for determining the aerobic biodegradation of plastic materials in soil.
- Covers aerobic biodegradation of plastic materials under controlled composting conditions
- Directly measures biodegradation without a pre-oxidation step
- Requires 60% conversion to CO2 within a specific timeframe to pass
- Does not include analysis of residues or oxidation
ASTM D6954 is a standard guide, while ASTM D5988 is a standard test method.
While both standards are used to test the biodegradability of plastics, ASTM D6954 is specifically designed for testing oxo-biodegradable plastics, while ASTM D5988 is designed for testing the aerobic biodegradation of plastic materials in soil.
