OECD Guidelines for the Testing of Chemicals, Test No 301 Ready Biodegradability

This test guide describes six test methods that allow chemicals to be screened for biodegradability in an aerobic aqueous environment. The methods are:

• OECD 301A Biodegradation test - Dissolved organic carbon
• OECD 301B Biodegradation test - Carbon dioxide evolution
• OECD 301C MITI biodegradation test
• OECD 301D Biodegradation sealed bottle test
• OECD 301E Modified biodegradation test - Dissolved organic carbon
• OECD 301F Biodegradation test - Oxygen consumption

OECD 301A is an aerobic biodegradation test for non-volatile and soluble substances. In this test method, the degree of biodegradation is measured by the exchange of dissolved organic carbon over a 28-day period. Ready biodegradability is achieved if the material meets the requirements set by the ready biodegradability method. Ultimate biodegradation can be measured if the sample meets final biodegradation requirements and provides the closest approximation to the total amount of material to biodegrade. Many chemical and physical properties can affect the biodegradability test, so it is important to report these properties to the laboratory before starting a biodegradation test.

OECD 301B is an aerobic biodegradation test that introduces a material into an inoculum in a closed environment and measures the biodegradation of the material with the formation of carbon dioxide. This test method uses respirometry to determine the biodegradability of the material by assessing carbon dioxide production in a liquid environment for a minimum of 28 days. This test method is used for materials that are highly soluble, poorly soluble, or even known to be insoluble at certain concentrations. Common materials tested with the OECD 301B test method include fuels, lubricants, oil, surfactants and personal care products. This test method is among the most commonly requested natural biodegradability methods.

OECD 301C is a modified MITI aerobic biodegradation test (Ministry of International Trade and Industry, Japan). This test method is a 28-day respirometry test that predominantly measures oxygen consumption. This method is suitable for poorly soluble materials and is used with samples of volatile materials. Although this test method looks very similar to other biodegradability tests, there are specific test parameters that differ from other methods.

OECD 301D is an aerobic biodegradation test method that can be used with poorly soluble materials and is suitable for samples of volatile and absorbent materials. This test method is a respiratory measurement test that predominantly measures biodegradation by dissolved oxygen and the test is a minimum of 28 days. Similar to other OECD 301 biodegradation methods, this test method can be used for ready, final or natural biodegradability.

The OECD 301E is a modified aerobic biodegradation test that measures the biodegradation of a material predominantly by assessing dissolved organic carbon. This test method is a 28-day minimum test that can be used with samples known to be absorbent material. OECD 301E and Similar to OECD 301A, but using a lower concentration of microorganisms than 301E. Ready biodegradability is achieved if the material meets the requirements set by the ready biodegradability method. Ultimate biodegradation can be measured if the sample meets final biodegradation requirements and provides the closest approximation to the total amount of material to biodegrade.

OECD 301F is a solution aerobic biodegradation test that determines the biodegradability of a material by measuring oxygen consumption. This test method is mostly used for insoluble and volatile materials challenged by the OECD 301B test. The purity or proportions of the main components of the test material are important for calculating the theoretical oxygen demand. Here, too, standard tests are 28 days minimum and can measure ready or final biodegradability.

Among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors, our organization also provides test no 301 ready biodegradability testing services, within the framework of OECD guidelines for the testing of chemicals, with its trained and expert staff and advanced technological equipment.