University of Texas at Austin Evaluating Environmental Partitioning and Fate: Approaches based on chemical structure David Allen Department of Chemical Engineering University of Texas at Austin

Software EPIWIN collection of software programs - Properties covered: l Properties used to estimate partitioning: boiling point, vapor pressure, octanol-water partition coefficient, bioconcentration factor, Henry’s law coefficient, soil sorption l Properties that govern environmental fate: atmospheric lifetimes, biodegradation rates

University of Texas at Austin Mackay et al., “Illustrated Handbook of Physical-Chemical Properties and Environmental Fate for Organic Chemicals”, Lewis Publishers, 1992 Water Compartment Only 1 kg Hexachlorobenzene (Hx) 10 5 m 3 volume of water kg organic carbon / m 3 water 0.1 kg fish / 100 m 3 water Case study 1: Environmental partitioning case study Human Exposure : Fish Ingestion 0.5 kg of fish consumed Dose due to ingestion? Concentration in the Fish (mg/kg)?

University of Texas at Austin EPWIN: SMILES NOTATION IT’S EASIER TO USE THE CAS NUMBER

University of Texas at Austin EPIWIN: CAS Number entry IT’S EASIER TO USE THE CAS NUMBER! USE A CAS SEARCH ENGINE: SciFinder Scholar / STNEasy CHEMFATE webbook.nist.gov CRCHandbook of Chemistry & Physics

University of Texas at Austin Case study 1: Mass balance equation for Hx

University of Texas at Austin EPIWIN: Software demonstration 10 5 m kg OC /m 3 3,388 L/ kg OC kg F / 10 2 m 3 5,152 L/ kg F m 3 /L Concentration in Water Concentration in Fish Dose to Humans

University of Texas at Austin Data Base vs. Prediction

University of Texas at Austin CHEMFATE

University of Texas at Austin PROPERTY REQUEST

University of Texas at Austin BENZENE OUTPUT

University of Texas at Austin Maleic anhydride EPIWIN (estimates) vs ChemFate (data) No data because MA hydrolyzes in 1 minute in water

University of Texas at Austin Benzene EPIWIN (estimates) vs ChemFate (data)