Shake flask biodegradation of 14 commercial phthalate esters.

An acclimated shake flask CO(2) evolution test was used to study the biodegradability of 14 commercial phthalate esters that are commonly used as plasticizers. Both CO(2) evolution (ultimate biodegradation) and loss of parent phthalate esters (primary biodegradation) were measured. With only a few exceptions, primary biodegradation was 90% or higher, and ultimate biodegradation was in excess of 55% of theoretical results in 28 days. The results showed that all of the commercial phthalate esters were susceptible to biodegradation by mixed populations of microorganisms from natural sources. The results also provide considerable insight into the utility and reproducibility of a standard biodegradation test that is being recommended for widespread screening of chemicals.