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Estimation Program Interface (EPI) Suite
What Does EPI Suite ™ Do?
• The EPI (Estimation Programs Interface) EPI Suite™ is a
Windows® based suite of physical/chemical property and environmental fate
estimation models developed by the EPA’s Office of Pollution Prevention
Toxics and Syracuse Research Corporation (SRC). EPI Suite™ uses
a single input to run the following estimation models: KOWWIN™, AOPWIN™,
HENRYWIN™, MPBPWIN™, BIOWIN™, BioHCWIN, PCKOCWIN™, WSKOWWIN™, WATERNT™,
BCFWIN™, HYDROWIN™, KOAWIN and AEROWIN™, and the fate models STPWIN™,
WVOLWIN™, and LEV3EPI™. EPI Suite™ was previously called EPIWIN.
• EPI Suite™ is a screening level tool and should not be
used if representative measured values are available.
• A clear understanding of the estimation methods and their appropriate
application is very important. Click on the Help tab in EPI Suite™
for information for the methods and models in EPI Suite™.
How Do the Individual Models that Make up EPI Suite™ Work?
• KOWWIN™: Estimates the log octanol-water partition coefficient,
log KOW, of chemicals using an atom/fragment contribution method.
• AOPWIN™: Estimates the gas-phase reaction rate for the reaction
between the most prevalent atmospheric oxidant, hydroxyl radicals, and a chemical.
Gas-phase ozone radical reaction rates are also estimated for olefins and
acetylenes. In addition, AOPWIN™ informs the user if nitrate radical reaction
will be important. Atmospheric half-lives for each chemical are automatically
calculated using assumed average hydroxyl radical and ozone concentrations.
• HENRYWIN™: Calculates the Henry’s Law constant (air/water
partition coefficient) using both the group contribution and the bond contribution
methods.
• MPBPWIN™: Melting point, boiling point, and vapor pressure
of organic chemicals are estimated using a combination of techniques.
Included is the subcooled liquid vapor presssure, which is the vapor pressure
a solid would have if it were liquid at room temperature. It is important
in fate modeling.
• BIOWIN™: Estimates aerobic and anaerobic biodegradability of
organic chemicals using 7 different models; two of these are the original
Biodegradation Probability Program (BPP™). The seventh and newest model
estimates anaerobic biodegradation potential.
• BioHCWIN: Estimates biodegradation half-life for compounds
containing only carbon and hydrogen (i.e. hydrocarbons).
• PCKOCWIN™: The ability of a chemical to sorb to soil and sediment,
its soil adsorption coefficient (Koc), is estimated by this program. EPI's
Koc estimations are based on the Sabljic molecular connectivity method with
improved correction factors.
• WSKOWWIN™: Estimates an octanol-water partition coefficient
using the algorithms in the KOWWIN™ program and estimates a chemical’s
water solubility from this value. This method uses correction factors to modify
the water solubility estimate based on regression against log Kow.
• WATERNT™: Estimates water solubility directly using a "fragment
constant" method similar to that used in the KOWWIN™ model.
• HYDROWIN™: Acid- and base-catalyzed hydrolysis constants for
specific organic classes are estimated by HYDROWIN™. A chemical’s hydrolytic
half-life under typical environmental conditions is also determined. Neutral
hydrolysis rates are currently not estimated.
• BCFWIN™: This program calculates the BioConcentration
Factor and its logarithm from the log Kow. The methodology is analogous
to that for WSKOWWIN™. Both are based on log Kow and correction factors.
• KOAWIN: KOA is the octanol/air partition coefficient and has
multiple uses in chemical assessment. The model estimates KOA using
the ratio of the octanol/water partition coefficient (KOW) from KOWWIN™, and
the dimensionless Henry's Law constant (KAW) from HENRYWIN™.
• AEROWIN™: Estimates the fraction of airborne substance sorbed
to airborne particulates, i.e. the parameter phi (φ), using three different
methods. AEROWIN™ results are also displayed with AOPWIN™ output as
an aid in interpretation of the latter.
• WVOLWIN™: Estimates the rate of volatilization of a chemical
from rivers and lakes; calculates the half-life for these two processes from
their rates. The model makes certain default assumptions-water body depth;
wind velocity; etc.
• STPWIN™: Using several outputs from EPI Suite™, this program predicts
the removal of a chemical in a Sewage Treatment Plant;
values are given for the total removal and three contributing processes (biodegradation,
sorption to sludge, and stripping to air.) for a standard system and set of
operating conditions.
• LEV3EPI™: This level III fugacity model predicts partitioning
of chemicals between air, soil, sediment, and water under steady state conditions
for a default model "environment"; various defaults can be changed
by the user.
What Do I Need to Use EPI Suite™?
• EPI Suite™ runs off of one single input, a representation
of the chemical structure in SMILES notation. SMILES is "Simplified Molecular
Input Line Entry System"; a description of this system is available with
the EPI Suite™ program. Entry of SMILES via a linked file of CAS
numbers included within the SMILECAS file in EPI Suite™ is also
possible; as is entry of only the chemical name using the Name Lookup utility,
if the entered name is in the linked name file.
How Are EPI Suite™ Data Used?
• EPI Suite™ provides users with screening level estimations
of physical/chemical properties and environmental fate properties. These properties
are the building blocks of exposure assessment. Before using the EPI Suite™
models to estimate these properties, users should first determine whether
any suitable data are available in the literature (e.g., Merck Index, Beilstein);
this is facilitated by a database of > 40,000 chemicals (called PHYSPROP)
included in the EPI Suite™ software. Dermwin™ , a
model that estimates the dermal permeability coefficient, Kp, is
included in EPI Suite™ , but can only be run from the EPI subdirectory
after download of EPI Suite™. ECOSAR is a model that predicts aquatic toxicity and is included in EPI Suite™. ECOSAR can also be downloaded as
a separate model from the ECOSAR home
page
Has EPI Suite™ been peer reviewed?
Individual estimation programs and/or their underlying predictive methods
and equations have been described in numerous journal articles in peer-reviewed
technical journals. The full reference citations are given in the Help
files for the individual programs. In addition, EPI Suite has undergone
detailed review by a panel of EPA’s independent Science Advisory Board
(SAB) (http://www.epa.gov/sab/, and
the September 2007 report can be downloaded here: Science Advisory Board (SAB) Review of the Estimation Programs Interface Suite (EPI Suite™) (PDF) (60pp, 473KB).
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PLEASE NOTE: the items mentioned at this page are in Adobe's Portable
Document Format (PDF). To view or print them you will need to have the Adobe
Acrobat Reader program installed on your computer. The Reader can be downloaded
and used with no charge; for
more information at EPA about PDF files.
Citing EPI Suite™
Full reference citations for the individual programs are given in the Help files for the individual programs. Cite the software itself as follows:
US EPA. [2007 or insert current year]. Estimation Programs Interface Suite™ for Microsoft® Windows, v[3.20 or insert version used]. United States Environmental Protection Agency, Washington, DC, USA.
What Type of Computer System Do I Need?
These programs run on Windows® 3.1X, Windows® 95/98,Windows NT®
and Windows XP/XP Professional®.
What's New?
• Description of Updates for EPI Suite Version 3.20 (February, 2007)
Copyright Notice; Terms and Conditions of Use:
© 2000-2007 U.S. Environmental Protection Agency for EPI Suite™ and all component programs except for BioHCWIN and KOAWIN.
Except for the BioHCWIN and KOAWIN models, EPI Suite™ and the individual models included within the software
are owned by the U.S. Environmental Protection Agency and are protected by
copyright throughout the world. Permission is granted for individuals to download
and use the software on their personal and business computers. Users may not
alter, modify, merge, adapt, distribute, or prepare derivative works from
the software. Users may not remove or obscure copyright, trademark, or proprietary
notices on the program or related documentation. EPI Suite™ and the
names of the individual models contained therein are trademarks owned by the
U.S. Environmental Protection Agency.
Who Can I Call for More Information?
For more information about the model, please contact:
Dr. Robert Boethling
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W. (Mail Code 7406M)
Washington, DC 20460
Phone # (202) 564-8533
e-mail:Bob Boethling
For Technical Support and Training on EPI Suite™, please contact:
Dr. Philip Howard
Syracuse Research Corporation
301 Plainfield Road
Syracuse, NY 13212
(315) 452-8417
e-mail:Dr. Philip Howard