OECD 301D: Ready Biodegradability Test - Closed Bottle (ISO/IEC 17025:2017 Accredited)
OECD 301D is an aqueous aerobic biodegradation test that determines the ready biodegradability of a material by measuring dissolved oxygen consumption during biodegradation in closed bottles. As one of the first-tier tests among OECD 301-303 standard methods, it aims at screening readily biodegradable materials normally within 28 days.
CONCEPT
OECD 301D selects chemicals that do not have to be tested further because high biodegradability is expected in sewage treatment plants if they pass the OECD 301D test. Measurement is based on nonspecific parameter -- the consumption of dissolved oxygen. It was developed to determine whether a chemical is potentially easily biodegradable, rather than to predict the actual rate, of biodegradation in the environment.
A material is considered Readily Biodegradable if 60% of degradation is reached within a 10-day window (normally for materials with single structures) in 28 days. The 10 day window is defined as beginning when 10% of the degradation is reached and ends after 10 days from this point (but before the 28th day).
If a sample passes the tests, it is considered readily biodegradable and is assumed to be able to undergo rapid and ultimate biodegradation in the environment. Therefore no further investigation on the biodegradability, toxicity, or other environmental effects is normally required.
If a sample fails the tests, it does not necessarily mean it cannot be degraded under more environmentally realistic conditions. Instead, higher tiers of tests such as OECD 302 or 303 should be conducted.
