Comparison of Serum Bottle Toxicity Test with OECD Method

Abstract

Serum bottle (SB) activated sludge toxicity test procedure is compared with the OECD procedure. The purpose of this study is to compare and contrast the two testing procedures so that one can complement the other. If the toxicity measurements obtained from the two testing procedures are comparable, users can select either procedure based on time constraint and equipment availability. Seventeen organic toxicants are selected for the comparison. The results show: (1) For chemicals with low volatility, the OECD procedure and SB procedure give comparable results for obtaining the IC50 of organic toxicants; and (2) for volatile chemicals, the SB procedure can be reliably used whereas the OECD procedure cannot because aeration in an open vessel strips out the chemical of interest and the culture is subjected to a concentration decrease with time. Four phenolic compounds are used for studying the effect on the IC50 results due to the origin of the activated sludge. Lab‐activated sludge grown on a complex, defined organic medium and sewage activated sludge gives comparable IC50 results.