Filling the gap: Estimating physicochemical properties of the full array of polybrominated diphenyl ethers (PBDEs)

Physicochemical properties of PBDE congeners are important for modeling their transport, but data are often missing. The quantitative structure–property relationship (QSPR) approach is utilized to fill this gap. Individual research groups often report piecemeal properties through experimental measurements or estimation techniques, but these data seldom satisfy fundamental thermodynamic relationships because of errors. The data then lack internal consistency and cannot be used directly in environmental modeling. This paper critically reviews published experimental data to select the best QSPR models, which are then extended to all 209 PBDE congeners. Properties include aqueous solubility, vapor pressure, Henry's law constant, octanol–water partition coefficient and octanol–air partition coefficient. Their values are next adjusted to satisfy fundamental thermodynamic equations. The resulting values then take advantage of all measurements and provide quick references for modeling and PBDE-contaminated site assessment and remediation. PCBs are also compared with respect to their properties and estimation methods. -- Highlights: •Property data of PBDEs and reported experimental and estimation methods were reviewed. •Missing data were estimated for all 209 PBDEs based on selected methods. •All data were adjusted to meet thermodynamic constrains using a VisualBasic program. •The established database provides a quick reference for PBDE environmental modeling. -- Through careful selection of literature data, structure–property estimation and adjustment, key properties of 209 PBDE congeners are estimated with internal consistency