Molecular size as a limiting characteristic for bioconcentration in fish.

: The relationships between the bioconcentration factor (BCF) of chemicals in fish and their size, as characterized by molecular weight (MW), effective cross sectional diameter (Deff), and maximum diameter (Dmax) have been investigated using an experimental data set of 737 new and 441 existing chemicals monitored by the Japanese Chemical Substances Control Law (CSCL). Substances with BCF > or = 5000 (very high bioconcentration potential) typically have MW or = 1000 (high bioconcentration potential) have MW or = 1000 and Dmax > or = 1.5 nm have Deff < 0.95 nm.