EPA/600/R-13/277 I February 2014 I www.epa.gov/research
United States
Environmental Protection
Agency
Program for Assisting the
Replacement of Industrial
Solvents
PARIS III
User's Guide
Office of Research and Development
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DISCLAIMER
The information in this document has been funded wholly by the U.S. Environmental Protection Agency
(EPA). It has been subjected to the Agency's peer and administrative review, and has been approved for
publication as an EPA document. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
Although a reasonable effort has been made to assure that the results obtained are correct, the
computer programs described in this manual are experimental. Therefore the author and the U.S.
Environmental Protection Agency are not responsible and assume no liability whatsoever for any results
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Table of Contents
Disclaimer ii
Table of Contents iii
Introduction 4
System Requirements 5
Current Mixture Screen 6
Impact Factors Screen 8
Physical Properties Screen 10
Activity Coefficients Screen 11
Solvent Mixtures Screen 12
Reference Information 13
Tutorial 14
Appendix 1: Definition of Properties and Chemical Terms 16
Appendix 2: Definition of Environmental Indexes and Air Indexes 17
Abbreviations 21
Literature Cited 21
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Introduction
PARIS III is a third generation Windows-based
computer software to assist the design of
solvents by estimating values of the solvent
properties that characterize the static, dynamic,
performance, and environmental behavior of the
solvent. PARIS III works with single solvents or
solvents with multiple components. PARIS III
finds either a single chemical or a mixture that
matches these estimated values within user-
defined tolerances. PARIS III allows the user to
search for replacement solvents with higher or
lower values of any of these parameters to suit
particular applications. Using PARIS III, one
could, for example, design a chemical mixture
that had an airtoxicity index half the value of
that in the currently used solvent while keeping
other properties approximately constant or even
improving them.
Aquatic Toxicity Potential
Global Warming Potential or GWP
Ozone Depletion Potential or OOP
Photochemical Oxidation Potential or PCOP
Acid Rain Potential or Acidification Potential
The user has wide latitude to weight the relative
importance of these environmental effects to suit
particular applications. All of these elements
function under the guidance of a powerful
solvent design algorithm to comprise a very
versatile tool.
The static properties considered by PARIS III
are molecular mass, molar volume, boiling point,
vapor pressure, surface tension, and infinite
dilution activity coefficients. The dynamic
properties are viscosity and thermal conductivity.
The performance requirement is the flash point.
The environmental requirements are an air index
and an overall environmental impact index.
PARIS III screens solvents to ensure the
replacements are only in liquid phase. Note that
the user needs to know the composition of the
solvent, but not the values for any of the
properties since the program either has them in
a database or has estimation methods for them.
PARIS III incorporates the PARIS III solvent
database of chemical and physical properties
with approximately 4000 chemicals. In addition,
a suite of pure fluid and mixture property
prediction routines is incorporated, including the
UNIFAC group contribution and other well-
established methods. To provide an indication of
the potential environmental impact of a solvent
formulation designed by PARIS III, a database
of relative environmental impact scores has
been created by drawing on government and
non-government sources. Eight different
categories of impact potential are considered:
Human Toxicity Potential by Ingestion
Human Toxicity Potential by Inhalation
Terrestrial Toxicity Potential
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System Requirements
It is recommended that PARIS III be run on 32
bit or 64 bit Windows PC compatible computers
with the Windows XP or Windows 7 operating
system, and a minimum of 2.0 GB RAM and an
Intel Xeon processor with a clock speed of 2.66
GHz or greater. Note that there are a number of
algorithms in PARIS III that are computer
resource intensive, so PARIS III will run faster
on higher-end machines.
To use all the functionality of PARIS III, free
hard disk space of about 10 GB is required.
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Current Mixture Screen
Purpose and Description
On this screen, information about the current
solvent mixture to be replaced is specified by
the user. This information will be used by the
program to replace the current solvent with a
single chemical or a mixture of chemicals. The
process of finding a replacement for a solvent
using PARIS III begins with the user entering
information about the current solvent's
composition and the operating conditions at
which the solvent is used. The operating
temperature and pressure are used to
determine the list of chemicals (from the
complete list of chemicals in the PARIS III
solvent database) in liquid phase at the
specified conditions.
Buttons and Information
System Name
A name for the current solvent system is
entered here. This name will be used to refer
to the current system in the following screens.
Units: SI
If this option is selected, the SI system, whose
three basic units are the meter (m), the
kilogram (kg), and the second (s), will be used
to display all the chemical properties. These
will be used in internal calculations.
Unit: Common
If this option is selected, the most common
units will be used to display each chemical
property. The SI system will be used in internal
calculations.
Units: US
If this option is selected, the American or FPS
system, whose three basic units are the foot
(ft), the pound (Ib), and the second (s), will be
used to display all the chemical properties.
However, the SI system will be used in internal
calculations.
Units: CGS
If this option is selected, the CGS system,
which uses the centimeter (cm), gram (g) and
the second (s), will be used to display all the
chemical properties. However, the SI system
will be used in internal calculations.
Temperature
The temperature at which the current system is
used is specified here. Whatever units are
selected, the default temperature of 25.OC is
set.
Pressure
The pressure at which the current system is
used is specified here. Whatever units are
selected, the default pressure of 1.0 atm is set.
Chemical Display Options
To select the chemicals that are in the current
solvent, the user has to select chemicals from
the PARIS III solvent database. To facilitate
searching and viewing, chemicals in the
database can be viewed by searching for
chemicals by name or by specifying chemicals
by CAS number.
Search for Chemicals by Name
If this option is selected, the user can type the
chemical name in the "Chemical Name
Search" box. The program will automatically
search through chemical names and bring up
the closest matched chemical name in the
"Chemicals" list box. The user can directly go
to the "Chemicals" list box and select the
chemical name. Any chemical within the
database that has no chemical name on file is
listed by CAS number.
Search for Chemicals by CAS Number
If the user knows the CAS number of their
solvent, the user can search by supplying a
CAS number (with the format *-xx-x). If this
option is selected, the user enters the CAS
number of the chemicals in their solvent
system. The program will automatically search
the CAS Numbers for you and bring up the
closest matched CAS Number in the
"Chemicals" list box. The user can directly go
to the "Chemicals" list box and select the
chemical by CAS Number.
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Mixture list
Chemicals present in the current solvent
system are to be specified here. Chemicals
can be selected by clicking on the chemical in
the Chemicals list and then clicking the > Add
button to copy the chemical by name to the
Mixture list. A maximum of four chemicals can
be specified in one formulation.
< Remove
When this button is clicked, the selected
chemical from the Mixture list is removed.
Mixture Percentage Options
Wt% can be changed to Mol% by clicking on
this button.
Option: Wt%
The user can enter the composition on a
weight % basis or on a mole % basis. The
weight % of a chemical in the current solvent
system is specified here. If the total weight %
of all the components in the Mixture list is not
100%, an error message is displayed when
leaving this screen.
Option: Mol%
The user can enter the composition on a
weight % basis or on a mole % basis. The
mole % of a chemical in the current solvent
system is specified here. If the total mole % of
all the components in the Mixture list is not
100%, an error message is displayed when
leaving this screen.
Ref
When this button is clicked, information on the
properties of the chemical selected in the
Chemicals list is displayed on a popup screen.
The source for data displayed in the reference
screen is the PARIS III solvent database.
Chemicals
The database of chemicals contains all the
liquid chemicals included in the PARIS III
solvent database. These chemicals can be
selected as components of the current solvent
system.
> Add
When this button is clicked, the selected
chemical from the "Chemicals" list is added to
the Mixture list. Duplicate entries are not
allowed in the Mixture list.
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Impact Factors Screen
The Environmental Impact categories are:
Purpose and Description
On this screen, impact factors for each
potential environmental impact are specified by
the user. In this step, the user assigns an
impact factor to each of the environmental
impact categories to suit their particular
application. Higher impact factors should be
placed on categories that are more important
to the user. These factors are used in
subsequent steps of the program to rank and
select chemicals to be replacements. Eight
categories of environmental impacts are
included in PARIS III to estimate the potential
environmental impact of a solvent system.
Buttons and Information
User Assigned Weights
The weight oq for each of the eight categories
expresses the importance of that impact
category relative to the other impact
categories. Initially, PARIS III assigns a default
value of 5 to all of the weighting factors. This
implies that all of the impact categories are
equally important. The user can override the
default values and assign a more appropriate
weight. This allows the environmental impact
to be customized to the environmental
concerns of a particular facility. For example, if
the chemical process facility is located in an
area where air pollution is a serious concern,
then the user may decide to raise the
weighting factor for the Photochemical
Oxidation Potential (PCOP) above its default
value. If the process plant is discharging to a
water body, then the user may choose to raise
the value of the factor for Aquatic Toxicity
Potential above its default value. If any one of
the impact categories is deemed irrelevant for
a particular design, the weight can be lowered
to a value that is more representative of that
concern, possibly a value of 0. For example,
someone considering a process that operates
in the middle of a desert may not be as
concerned with the emission of chemicals that
have Acid Rain Potential (ARP) and would
accordingly decrease that weight.
Human Toxicity Potential by Ingestion
Human Toxicity Potential by Inhalation
Terrestrial Toxicity Potential
Aquatic Toxicity Potential
Global Warming Potential or GWP
Ozone Depletion Potential or OOP
Photochemical Oxidation Potential or PCOP
Acid Rain Potential or Acidification
Potential
Default
Click on this button to use the default weight
for all environmental impact categories.
User Assigned Weights - Up and Down
Arrows
The Up and Down arrows are used to assign a
weight from 0 to 10 for an environmental
impact criterion. The higher the number is, the
greater the importance given to that
environmental impact category in finding
replacements.
Chemicals
The names of the solvents in the original
mixture are given in each row.
Wt%
In this column, the weight percentage of each
solvent in the original mixture is given in each
row. The total weight percentage of the
solvents is given in the last row and should
always be 100%.
Environmental Impact Categories
The normalized environmental impact value of
each solvent is given under each respective
category (e.g., Human Toxicity Potential by
Inqestion, Human Toxicity Potential by
Inhalation) and does not change.
Totals
Each value in the final column represents the
total environmental impact contributed by each
solvent in the mixture. These solvent impacts
in the final column add up to give the total
environmental impact of the whole mixture that
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is shown in the bottom right corner of the table.
This is the Environmental Index of the solvent
mixture to be replaced.
Similar to the layout described above, each
value in the bottom row represents the total
environmental impact for each category of
environmental impacts multiplied by impact
factors set by the user. As before, a sum of
the values across the bottom row is equal to
the Environmental Index of the solvent mixture
to be replaced.
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Physical Properties Screen
Purpose and Description
The purpose of this screen is to show how the
physical properties of possible solvent
replacements compare to the properties of the
original solvent mixture. This includes a listing
of either single solvent replacements or
mixture solvent replacements.
Buttons and Information
Property
These are the names of the physical and
environmental properties for which data is
displayed.
Tolerance (%)
The tolerance percentage is used to calculate
the lower and upper bounds a replacement
solvent property might have from the desired
property of the original mixture. This tolerance
percentage may be altered from the default
values to modify the ranking of replacement
solvents.
Units
The set of property units chosen from the
Current Mixture Screen will be displayed in this
column.
Single/Mixture Solvent Replacements
In this listing, the names of possible
replacement solvents are given and are ranked
by those solvents whose properties are closest
to the properties of the original solvent mixture.
The integer number that appears before the
solvent name is the total number of physical
and chemical properties that are not within
bounds of the desired property value. Clicking
on a solvent's name in this list will display the
possible replacement solvent's properties in
the replacement column.
Single/Mixture button
Once an analysis of possible solvent mixtures
has been performed, the Mixture button will be
available to view ranked solvent mixtures as
possible replacements for the original solvent
mixture. If the Mixture button is selected, a table
will appear below the replacement list showing
the weight percentage of each component in the
solvent mixture selected
Lower
This is a lower bound for the replacement
solvent's property.
Desired
This is the desired value of the replacement
solvent's property. By default, it is the property
value of the original solvent mixture, but may
be changed.
Upper
This is an upper bound for the replacement
solvent's property.
Replacement
This is the property value of the selected
solvent replacement. Green values are within
the bounds of the desired value, and red
values are outside the bounds of the desired
value.
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Activity Coefficients Screen
Purpose and Description
The purpose of this screen is to show how the
chemical properties of possible solvent
replacements compare to the chemical
properties of the original solvent mixture. This
includes a listing of either single solvent
replacements or mixture solvent replacements.
Buttons and Information
Substance Name
These are the chemicals that act as solutes for
infinite dilution activity coefficients.
Tolerance (%)
The tolerance percentage is used to calculate
the lower and upper bounds a replacement
solvent property might have from the desired
property of the original mixture. This tolerance
percentage may be altered from the default
values to modify the ranking of replacement
solvents.
replacement solvent are given which are
ranked by those solvents with properties
closest to those of the original solvent mixture.
The integer number that appears before the
solvent name is the total number of physical
and chemical properties that are not within
bounds of the desired property value. Clicking
on a solvent's name in this list will display the
possible replacement solvent's properties in
the replacement column.
Single/Mixture button
Once an analysis of possible solvent mixtures
has been performed, the Mixture button will be
available to view ranked solvent mixtures as
possible replacements for the original solvent
mixture. If the Mixture button is selected, a table
will appear below the replacement list showing
the weight percentage of each component in the
solvent mixture selected.
Tolerance Scale Factor
By shifting this scale factor, all tolerances can be
increased or decreased by the same factor. This
changes all lower and upper bounds, and
consequently how chemicals are ranked.
Lower
This is a lower bound for the replacement
solvent's property.
Desired
This is the desired value of the replacement
solvent's property. By default, it is the property
value of the original solvent mixture, but may
be changed.
Upper
This is an upper bound for the replacement
solvent's property.
Replacement
This is the property value of the selected
solvent replacement. Green values are within
bounds of the desired value, and red values
are outside the bounds of the desired value.
Single/Mixture Solvent Replacements
In this listing, the names of possible
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Solvent Mixtures Screen
used in the search.
Purpose and Description
The purpose of this screen is to perform a
search to find out if the solvents selected may
be mixed together in the right proportions to
come close to imitating the properties of the
original solvent mixture, but have less
environmental impact. This is achieved by
including in the search only solvents that are
greener than the original solvent mixture, and
mixing various proportions of these chosen
solvents together until the total search has
been completed.
Buttons and Information
Primary Solvent List
This is the ranked list of single solvents from the
Physical Properties Screen and the Activity
Coefficients Screen. They are to be used as the
primary solvent of the mixture being
investigated. Any number of solvents from this
list may be selected and used in the mixture
search.
Secondary Solvent List
This is the ranked list of single solvents from the
Physical Properties Screen and the Activity
Coefficients Screen. They are to be used as the
secondary solvent of the mixture being
investigated. Any number of solvents from this
list may be selected and used in the mixture
search.
Tertiary Solvent List
This is the ranked list of single solvents from the
Physical Properties Screen and the Activity
Coefficients Screen. They are to be used as the
tertiary solvent of the mixture being investigated.
Any number of solvents from this list may be
selected and used in the mixture search.
Best Solvents
This chooses the 10 highest-ranking solvents to
be used in the search.
All Green Solvents
This chooses all of the ranked solvents that are
greener than the original solvent mixture to be
Initial Solvents
This chooses all of the solvents from the original
solvent mixture to be added to the list of
solvents that are used in the search.
All Solvents
Sometimes it may be useful to add small
portions of solvents that are not necessarily
greener than the original solvent mixture into the
solvent mixture search. Unchanged, this would
add all solvents in the PARIS III solvent
database into the search, but only a few should
be highlighted and selected.
Mass Ratios
Only the selected mass proportions will be used
in the solvent mixture search.
Find Mixtures
Once the solvents and mass ratios of the
combinatorial search have been chosen, the
search is started by choosing this option from
the Action submenu on the Main menu bar.
Stop Mixtures
After the parameters of the combinatorial search
have been chosen and the search has been
started, the search can be stopped by choosing
this option from the Action submenu on the
Main menu bar. This will stop any further search
and display only the best results that have been
achieved so far.
Progress Bar
The progress bar on the bottom of the screen
displays how the search is progressing.
Best Mixtures List
After the combinatorial search has been
performed, the 250 best mixtures are ranked by
how close the properties of this mixture are to
the properties of the original solvent mixture.
The integer number that appears before the
mixture's name is the total number of physical
and chemical properties that are not within
bounds of the desired property value. When a
mixture is selected, the components and
proportions are shown in the table below the
Best Mixtures list. The values of the properties
of this mixture are listed in the Replacement
column on the Physical Properties Screen and
the Activity Coefficients Screen.
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Reference Information
Purpose and Description
This screen displays information about the
selected chemical contained in the PARIS III
solvent database.
Buttons and Information
Many formal pieces of information about the
solvent selected, such as the chemical name,
formula, CAS number, structure, and synonyms,
are included. In addition, multiple static and
thermodynamic properties of the solvent are
included.
Press the OK button to close the window and
return to the Current Mixture Screen.
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Tutorial
used are listed in the Mixture list on the bottom
of the Current Mixture Screen.
From the PARIS III website,
http://www2.epa.gov/chemical-
research/program-assisting-replacement-
industrial-solvents-iii-paris-iii download and save
the correct version of PARIS III depending on
whether you are using a Windows, Apple, or
Unix operating system. If your browser offers the
option to run the setup, then do so. Otherwise
have your browser display its list of recent
downloads and select the setup file to run it.
Once PARIS III is installed, launch PARIS III
from either the desktop or the "All Programs"
menu. An initial PARIS III Window pops up with
a picture of the Eiffel tower and several buttons.
One button is the "Start" button. Click on this
button. The main screen of PARIS III should
open up with the "Current Mixture" screen
selected.
The main screen of PARIS III has five tabs that
may be selected to open various screens. These
are the "Current Mixture" tab, the "Impact
Factors" tab, the "Physical Properties" screen,
the "Activity Coefficients" tab, and the "Solvent
Mixtures" tab. In addition, there are four main
menu options. The options are "File," "Edit,"
"Action," and "Help". From the Current Mixture
Screen, choose the "File" main menu option.
A submenu drops down from the "File" option
with many selections. Choose the "Open" option.
A window pops up with a selection of files from
the directory where PARIS III was started.
Select the file "RollerWash.xml" and the file
name should appear in the popup window.
Then, click on the open button in the popup
window. The popup window disappears and
information from that file appears on the
"Current Mixture" screen.
The "RollerWash.xml" file selected contains
information about a common solvent mixture
used to clean ink from the rollers of a printing
machine that prints the labels of products being
marketed. Unfortunately, this common solvent
mixture has a bad effect on the environment
when disposed of. The question examined by
PARIS III is "Can a similar solvent mixture be
found that cleans ink from the rollers, but is not
as harmful to the environment when released?"
The chemical components of the solvent mixture
When the "Impact Factors" tab is selected, the
Impact Factors Screen opens up with the
impacts these components have on eight
different categories of environmental impacts.
The impact factors with a default value of 5 for
each environmental category are listed across
the top of the screen. These may be changed by
the user to better reflect the environment where
the replacement solvent mixture is to be used.
But, leave these impact factors at their default
values for now. The number appearing in the
lower right corner is the Environment Index of
the original solvent mixture to be replaced.
Continue to the next screen by selecting the
"Physical Properties" tab.
The Physical Properties Screen displays the
properties of the original solvent mixture, mostly
under the "Desired" column. The upper and
lower bounds of how close the replacement
solvent mixture should be to the desired
property value are represented by the "Upper"
and "Lower" columns. These upper and lower
bounds are calculated by the default tolerance
percentages listed under the "Tolerance (%)"
column. These default values may be modified,
but leave them the same for now. Note that, for
safety, the desired Flash Point value of the
original solvent mixture appears as a lower
bound for replacement mixtures. Similarly, the
Environmental Index and the Air Index of the
original solvent mixture appear as an upper
bound for the replacement mixtures to ensure
that only greener solvents are considered as
replacements.
On this screen, the Single Solvent Replacement
box shows a ranked list of all solvents within the
PARIS III solvent database that are greener than
the original solvent mixture. These are ranked
by how close their properties are to those of the
original solvent mixture. The replacement
properties that are within the bounds are shown
in green, and the properties outside the bound
are shown in red. The integer that appears in the
list before the replacement name is a count of
the total number of properties shown in red on
this screen and on the Activity Coefficients
Screen.
The next screen appears by selecting the
"Activity Coefficients" tab. This screen is very
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similar in function to the previous screen except
that infinite dilution activity coefficients are
displayed here instead of physical properties.
The solutes of the infinite dilution activity
coefficients are listed under the Substance
Name column. Note the integer that appears
before the name of the selected solvent
replacement is the total number of the
replacement properties that show in red on the
two screens.
Selecting the final tab brings up the Solvent
Mixtures Screen. The solvents that appear in the
solvent lists are the same ranked list of solvents
from the two previous screens. Initially, the
primary solvents come up with the 10 best
solvents selected. By clicking on the Secondary
button, the secondary solvents are brought up,
again with the 10 best solvents selected. Notice
how a selected list of mass ratios was brought
up. The search for solvent mixtures that could
make good replacements is a combinatorial
search among all the selected solvents and
mass ratios. The selected included in the search
can be easily changed. By clicking on the
Action menu and selecting the "Find Mixtures"
option, the search is started.
After the search, the 250 best-ranking
replacements are shown in the Best Mixture list.
Notice how the integer number that appears
before the best mixture name has changed from
a 7 on the previous single solvent replacement
list to a 5 on the solvent mixture replacement
list. This means that only five properties are
outside of the bounds for all of the physical and
chemical properties of the original solvent
mixture. By clicking on the Tertiary button, and
selecting the "Find Mixtures" option under the
Action menu, the next mixture search is started.
After this search, again the best mixture has five
properties outside of bounds of the original
solvent mixture, but a wider selection of mixtures
with similar compliances may be chosen from.
We might improve the Best Mixtures list by
selecting more solvents to be used in the
search. Clicking on the Tertiary button again
turns it off, but clicking on "All Green Solvents"
under the Secondary button enhances the
selection of solvents used as secondary
solvents in the search. By selecting the "Find
Mixtures" option under the Action menu, the
search starts again with these solvents and
mass ratios selected. This combinatorial search
will take longer because of the greater number
of combinations selected. Notice that after this
search the best mixture has only three
properties outside of bounds of the original.
By going back to the Activity Coefficients
Screen, the infinite dilution activity coefficients
that are outside of the bounds of the original
solvent mixture are shown in red. By going to
the Physical Properties Screen, the properties
are all shown to be within bounds. We can
select various mixtures in the Solvent
Replacement list and compare how the
Environmental Index and the Air Index are
reduced. The sixth solvent mixture down in the
list reduces these indexes significantly, while
keeping most of the properties within range.
With the sixth mixture selected, all of the
physical properties are within bounds. By
proceeding to the Activity Coefficients Screen,
for the same mixture the ethanol infinite dilution
activity coefficient is outside of bounds. If it is not
important that the replacement mixture's ethanol
activity coefficient is close to that of the original
mixture, the tolerance percentage can be
increased from 25.0 to 32.0. Then, clicking on
the desired value changes the lower and upper
bounds and brings the ethanol activity coefficient
within bounds. Likewise, after changing the
same mixture's tolerance fordiethyl ether from
30.0 to 57.0, for n-propyl-amine from 30.0 to
67.0, and for dimethyl disulfide from 30.0 to
53.0, all properties are within bounds.
All of these changes can be seen by going back
to the Solvent Mixtures Screen, clicking on the
secondary button, and selecting the All Green
Solvents button. By performing the search
again, two possible solvent mixture
replacements are found that are all within the
bounds of the original solvent mixture. It only
remains to go back to the Physical Properties
Screen to compare and write down those
solvent mixtures that reduce the environmental
indexes the most. These are the less harmful
solvent mixtures that may then be substituted in
industrial processes for the original mixture to
verify they make good solvent replacements.
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Appendix 1: Definition of
Properties and Chemical Terms
Molecular Weight - Is the sum of the atomic
weights of all the atoms in a molecule.
Mole - The SI unit of amount of substance. It is
equal to the amount of substance that contains
as many elementary units as there are atoms in
0.012 kg of carbon-12. The elementary units in
the PARIS III program are molecules.
Mole Fraction - This is the fraction of total
moles that each component of a mixture has.
The mole fraction of component A is given by:
xA = nA/N, where nA is the number of moles of
A and N is the total number of moles of all
components in the mixture.
Molar Volume - The volume occupied by one
mole of a substance. The density is equal to 1.0
/ (molar volume).
Weight Fraction - This is the fraction of total
mass that each component of a mixture has.
Boiling Temperature - Is the temperature at
which a pure chemical boils. In PARIS III, the
boiling temperature of a mixture is set equal to
the bubble temperature, which is the
temperature at which gas bubbles form in the
liquid.
Vapor Pressure - The pressure exerted when a
solid or liquid is in equilibrium with its own vapor.
The vapor pressure is a function of the
substance and temperature.
Surface Tension - Due to molecular attractions,
two fluids in contact exhibit tension. For
example, a liquid with high surface tension will
not readily mix with another liquid.
Viscosity - All fluids possess a definite
resistance to change of form. This property, a
sort of internal friction, is called viscosity.
Thermal Conductivity - This is the property of
how easy it is for a material to conduct heat. It
is given by the time rate of transfer of heat by
conduction, per distance per difference of
temperature.
Flash Point - The temperature at which the
vapor above a volatile liquid forms a combustible
mixture with air. At the flash point, the
application of a naked flame gives a momentary
flash rather than sustained combustion.
UNIFAC - Acronym for Universal Functional
Activity Coefficient. It is a method for estimating
the effect of non-idealities on mixtures from the
contributions of the groups making up the
molecules present in a mixture. This method is
widely used.
Activity Coefficient - Is a factor that
characterizes the non-ideality of a mixture. It
depends on temperature, pressure, mixture
composition, and the forces between the
molecules. The activity coefficient for a chemical
A at infinite dilution in a solvent or mixture is
calculated by letting the mole fraction of the
chemical A go to zero.
Infinite Dilution Activity Coefficient - The
infinite dilution activity coefficient represents the
molecular interactions between one molecule of
each of the specified ten chemicals and the
molecules in the solvent. Each of the ten
chemicals is a prototype of a commonly used
family of chemicals. The infinite dilution activity
coefficient is used to match the molecular
behavior of proposed replacements to that of the
original solvent. This helps to ensure the
replacement will perform as well as the original.
PARIS III Solvent Database - Organized by the
U.S. Environmental Protection Agency and
represents an effort dedicated to the compilation,
measurement, and evaluation of physical
property data for industrially important chemicals.
The database contains physical, thermodynamic,
and transport property data for about 5000 of the
most commonly used chemicals. This
compilation contains critically evaluated,
internally consistent data.
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Appendix 2: Definition of
Environmental Indexes and Air
Indexes
Eight environmental impact scores q>t .:
Human Toxicity Potential by Ingestion
Human Toxicity Potential by Inhalation
Terrestrial Toxicity Potential
Aquatic Toxicity Potential
Global Wanning Potential or GWP
Ozone Depletion Potential or OOP
Photochemical Oxidation Potential or PCOP
Acid Rain Potential or Acidification Potential
Normalized environmental impact score cpt j :
Assuming that a score of 1 is average for all the
chemicals, the normalized environmental impact
scores are calculated from:
0)
Where cpt . is the normalized environmental
impact score of chemical /for impact j, q>t . is
the environmental impact score of chemical /for
impact j, and N is the total number of non-zero
impacts for chemicals.
Environmental Index - Is the overall relative
measure of the potential impact of a chemical or
a mixture on human health and the environment.
This includes all of the eight impact categories
mentioned above. For a pure chemical;', it is
calculated from:
(2)
7=1
chemical;', and the summation is taken over the
eight categories of impacts in PARIS III, a^ is
the user-assigned weight of impact y
independent of chemical;', and q>i j is the
normalized impact score of chemical /for impact
j, as calculated by equation (1).
For a mixture, a weight fraction averaged index
is calculated from:
(3)
7=1
Where *¥M is the mixture environmental index
for mixture M , Wi is the weight fraction of
chemical/ in the mixture, and the summation is
taken over all chemicals present in the mixture.
Air Index - Overall relative measure of the
potential impact of a chemical or a mixture
mediated through the air on human health and
the environment. The air index is calculated by
multiplying the environmental index of each
chemical by its fugacity in the liquid phase. The
fugacity gives an estimate of the tendency of a
chemical to vaporize. For a pure chemical, the
air index is given by
(4)
p
Where Ptv is the vapor pressure of component
;', *?. is the environmental index of component
chemical i as given by equation (2), and P is
the pressure at which the solvent is being used.
For a solvent consisting of a mixture of
component chemicals, the mixture air index is
given by
XT/ air _
T ~~
(5)
Where x, is the mole fraction of chemical
Where Y, is the environmental index of
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component;', yt is the activity coefficient of
chemical component;', Ptv is the vapor pressure
of chemical component;', *?. is the
environmental index of component chemical; as
given by equation (2), M. is the molecular
mass of component chemical;', and P is the
pressure at which the solvent is being used.
The Environmental Impact Categories are
defined as follows:
Human Toxicity Potential by Ingestion
Human Toxicity Potential by Ingestion is
approximated by the value of the lethal dose
through ingestion that would kill 50% of a
sample population of rats, which is known as the
oral ratZD50. This is a popular indicator for
evaluating the toxicity of chemicals. The LD50 is
generally reported in units of (mg of chemical/kg
of rat). In this system, a higherZD50 value
represents a less toxic chemical. Thus, to align
these impact values with the other impact
values, the scores were obtained by inverting
the LD50 values.
),.
Use of the equation allowed for proportional
relationships to be maintained. For example, a
chemical with an LD50 of 200 mg/kg, producing
a
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through ingestion that would kill 50% of a
sample population of rats, which is known as the
oral raiLD50. This is a popular indicator for
evaluating the toxicity of chemicals. The LD50 is
generally reported in units of (mg of chemical/kg
of rat). In this system, a higherZD50 value
represents a less toxic chemical. Thus, to align
these impact values with the other impact
values, the scores were obtained by inverting
the LD50 values.
9 = 1
Use of the equation allowed for proportional
relationships to be maintained. For example, a
chemical with an LD50 of 200 mg/kg, producing
a p. = 0.005 , is considered to be twice as
harmful as a chemical with an LDjj of
chemical; for GWP impact. These values were
obtained from Houqhton et al. (1992) and
Heijunqs et al. (1992). These amounts take
into account the decomposition of the
chemicals in the atmosphere.
Limitations: These values have only been
tabulated for a few simple gases and a limited
amount halogenated hydrocarbons. However,
the chemicals of primary concern regarding
global warming have been captured in the
analysis of this impact category. The
decomposition products are not included as
sources for GWP.
Ozone Depletion Potential
Ozone Depletion Potential (OOP) is
by comparing the rate at which a unit mass of
chemical reacts with ozone to form molecular
oxygen to the rate at which a unit mass of
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CFC-11 (trichlorofluoromethane) reacts with
ozone to form molecular oxygen. In general,
for a chemical to have an OOP, it must contain
a chlorine or bromine atom. The OOP takes
into account the decomposition of the
chemicals in the atmosphere.
This relative value was used as the score q>jj
of the chemical /for OOP impact. These
values were obtained from World
Meteorological Organization (1991) and
Heijungs et al. (1992).
Limitations: These values have only been
tabulated for a limited amount of halogenated
hydrocarbons. However, the chemicals of
primary concern have been captured in the
analysis of this impact category. The
decomposition products are not included as
sources for OOP.
Photochemical Oxidation Potential
Photochemical Oxidation Potential (PCOP) is
determined by comparing the rate at which a
unit mass of chemical reacts with a hydroxyl
radical (OH ) to the rate at which a unit mass of
ethylene reacts with OH . These values have
been determined for many low and medium
molecular weight hydrocarbons.
This relative amount is used as the score cp \\ of
chemical /for PCOP impact. These values
were obtained from UNECE (1991) and
Heijungs et al. (1992).
Limitations: The values used in this impact
category were determined through analysis
performed in Europe and may not adequately
represent the concern in the United States.
Acid Rain Potential
Acidification or Acid Rain Potential (ARP) is
determined by comparing the rate of release of
H+ in the atmosphere as promoted by a
chemical to the rate of release of H+ in the
atmosphere as promoted by SO2.
This relative amount is used as the score cp \\ of
chemical /for ARP impact. These values were
obtained from Heijungs et al. (1992).
Limitations: Values are calculated for a
limited number of chemicals of primary
concern regarding acid rain.
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Abbreviations
ACGIH - The American Conference of Governmental Industrial Hygienists
AQUIRE - Aquatic Toxicity Information Retrieval Database
ECOSAR - Ecological Structure Activity Relationships
HSDB - Hazardous Substance Database, NIH
NIH - The National Institute of Health
NIOSH - The National Institute for Occupational Safety and Health
OSHA - The Occupational Safety and Health Administration
RTECS - Registry of Toxic Effects of Chemical Substances
UNECE - United Nations Economic Commission for Europe
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