Test No. 310: Ready Biodegradability - CO2 in sealed vessels (Headspace Test)
This test determines if a chemical is readily biodegradable under aerobic conditions (meaning in the presence of oxygen).
This knowledge is crucial for assessing the chemical’s potential persistence and environmental impact.
Method:
- The test substance is incubated in sealed bottles containing a buffer-mineral salts medium and inoculated with a mixed population of microorganisms from activated sludge.
- The carbon dioxide (CO2) produced during biodegradation is collected and measured over time using headspace analysis.
- The extent of biodegradation is expressed as a percentage of the theoretical maximum CO2 production (ThCO2) based on the initial amount of the test substance.
Testing Criteria:
A chemical is considered readily biodegradable if:
- >60% ThCO2 is produced within 10 days during the 28-day test period.
- >70% ThCO2 is produced by the end of the test.
Applications:
The OECD 310 test is widely used by:
- Regulatory authorities for chemical registration and safety assessment.
- Chemical manufacturers for product development and environmental labeling.
- Researchers studying biodegradation processes and environmental fate of chemicals.
Benefits:
- Standardized and reliable method for assessing ready biodegradability.
- Relatively simple and inexpensive compared to other biodegradation tests.
- Provides valuable data for environmental risk assessment and decision-making.
Limitations:
- May not be suitable for all types of chemicals, especially volatile or poorly water-soluble substances.
- Does not provide information on the specific biodegradation pathways or the organisms involved.
- Cannot predict the long-term fate and effects of chemicals in complex environmental conditions.
Overall, the OECD 310 test is a valuable tool for screening chemicals for ready biodegradability and contributes to the development of safer and more environmentally friendly products.
