www.epa.gov/research
                            science   in   ACTION
                            INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE
     PARIS II: Computer Aided Solvent Design for Pollution Prevention
     Background
     Chemicals are essential to modern
     life. However, due to increasing
     awareness of the potential human
     health and environmental risks of
     solvent use, some industrial users
     may wish to switch to more benign
     solvents. This can be a difficult task
     because many parameters of
     different solvents need to be
     evaluated before a new  solvent or
     solvent mixture is selected.

     Project Overview and Purpose
     To support the use of benign
     solvents, U.S. EPA researchers
     developed the solvent substitution
     software tool PARIS II  (Program for
     Assisting the Replacement of
     Industrial Solvents, version 2.0).
     PARIS II finds less toxic solvents or
     solvent mixtures to replace more
     toxic solvents commonly used by
     industry. The greener solvents
     formulated by PARIS II have
     improved environmental properties,
     and perform as well as the solvents
     they replace.

     PARIS II is a cost-effective
     approach to pollution prevention
     because users do not have to change
     equipment in order to adopt safer,
     greener solvents. Designed to be
     user-friendly, the user need only
     know what solvents they are using to
     administer the application.

     Some of the industries that could
     benefit from using PARIS include
     Pharmaceuticals, paints, cleaners,
     chemical manufacture, plastics,
     degreasers, electronic component
     manufacture, and petrochemicals.

     Theory and Features
     The theoretical basis for the PARIS
     II program is the observation that the
     mathematical expressions governing
solvent behavior are universal, and
that the performance of solvent
mixtures may be quantified by a
number of coefficients representing
various physical and chemical
properties (e.g., viscosity, thermal
conductivity, activity, etc.).
Likewise, the environmental toxicity
of solvent mixtures may be
quantified by values taken from
several different categories of
environmental impact (e.g. aquatic
toxicity, terrestrial toxicity, acid
rain, ozone depletion, etc.).

The replacement process identifies a
toxic industrial solvent or solvent
mixture to be replaced, calculates its
physical and chemical property
coefficients, and calculates its total
potential environmental impact.
Then, the same property coefficients
and the total potential environmental
impact of various solvent mixtures
are calculated.

Within minutes, PARIS II can create
a ranked list of replacement solvent
mixtures that minimize the
difference of coefficients with the
original solvent and reduce the total
potential environmental impact.

Results and Discussion
PARIS II was used to develop
solvent substitutes for pure
chemicals and mixtures involving
components from a wide range of
chemical families, including normal
hydrocarbons, ketones, alcohols,
aromatics, ethers and organic and
aqueous mixtures. In several cases,
PARIS II was used to identify
substitutes for solvents that appear
on the Agency's Resource
Conservation and Recovery Act
chemicals list.

Case studies demonstrate  that
PARIS II can suggest replacement
solvents with consistently lower
potential environmental impact
while likely maintaining similar
levels of technical performance.
Researchers have identified
replacement solvents with a fifth or
a sixth of the environmental effects
of the commonly used solvent.

Future Work
U.S. EPA researchers are working
on the next version of this software
tool, PARIS III. This next version
will have many significant changes,
including:
1) a new Graphical User Interface,
2) a new database of solvent
properties referenced,
3) and a new search mechanism to
find solvent mixture replacements.
The final version of this software
will be available for scientists to
download and use free of charge,
with a beta version of this software
available on October 1, 2013.

Collaborators
The development of PARIS II has
been implemented by the work of
researchers from the following
entities:
U.S. EPA Office of Research and
Development
Technical University of Denmark
Research Triangle Institute
University of Cincinnati

Contact
Paul Harten, Ph.D., Office of
Research & Development, 513-569-
7045, harten.paul@epa.gov

Reference
Harten, P.P., and G. Salama,
"PARIS II, the Search for Cleaner
Solvent Replacements for RCRA
Chemicals," Clean Tech., Vol. 4,
Number 11, p.  20(2004).
     U.S. Environmental Protection Agency
     Office of Research and Development
                                             Technical Fact Sheet
                                             EPA/600/F/12/622
                                             May 2013

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