to Green Chemistry
Green Module for General
for Inorganic Chemistry
Module for Environmental Chemistry
Module for Chemical
Module for Industri al
Chemistry at the University of Scranton
A Project with major funding from The Camille and
Henry Dreyfus Foundation Special Grant Program in the Chemical Sciences.
Additional funding was provided by the ACS/EPA Green Chemistry Educational
Materials Development Project and the University of Scranton.
Notes to Instructors
Introduction to Green Chemistry
Cann, Chemistry Department,
University of Scranton
The late sixties and early seventies
were times when the environment received a great deal of attention including
the formation of the Environmental Protection Agency (EPA) and the celebration of the first Earth
Day, both of which occurred in 1970. In the intervening years in excess
of 100 environmental laws have been passed. These include the twelve
major laws listed below.
- 1970 Clean Air Act. Regulates air emissions.
- 1972 National Environmental Policy Act. Requires
in part that EPA review environmental impact statements of proposed major
federal projects (e.g. highways, buildings, airports, parks and military
- 1972 Clean Water Act. Establishes the sewage treatment
construction grants program and a regulatory and enforcement program for
discharges of pollutants into U.S. waters.
- 1972 Federal Insecticide, Fungicide & Rodenticide
Act. Governs distribution, sale and use of pesticide products.
All pesticides must be registered (licensed) by EPA.
- 1972 Ocean Dumping Act. Regulates the intentional
disposal of materials into ocean waters.
- 1974 Safe Drinking Water Act. Establishes
primary drinking water standards.
- 1976 Toxic Substances Control Act. Requires
the testing, regulating, and screening of all chemical produced or imported
in the U.S.
- 1976 Resource Conservation & Recovery Act. Regulates
solid and hazardous waste form “cradle to grave.”
- 1976 Environmental Research & Development Demonstration
Act. Authorizes all EPA research programs.
- 1980 Comprehensive Environmental Response, Compensation
& Liability Act, better known as Superfund. Provides for a federal
“superfund” to clean up abandoned hazardous waste sites, accidental spills
and other emergency releases of pollutants in the environment.
- Emergency Planning & Community Right-to-Know
Act. Requires that industries report toxic releases and encourages
planning by local communities to respond to chemical emergencies.
- 1990 Pollution Prevention Act. Seeks to prevent
pollution by encouraging companies to reduce the generation of pollutants
through cost-effective changes in production, operation, and raw material
All of these acts, with one exception,
deal with pollution after it is formed. These laws are in general focused
on the treatment or abatement of pollution and have become know as “command
and control” laws. In many instances these laws, which were passed
by the US congress, place limits on pollution and timetables for compliance,
with little regard to whether the science/technology could attain these goals
and with little regard to the economic costs of these laws. Risk associated
with a toxic chemical is a function of Hazard and Exposure. The “end
of the pipe” laws attempt to control Risk by dealing with the prevention
of the Exposure to toxic hazardous chemicals. Of course all to often
prevention of Exposure has failed.
While these laws have accomplished
a great deal in terms of improving our environment by controlling our exposure
to hazardous substances, we still have a long way to go. For example
under the Toxic Release Inventory (TRI),
which is part of the Emergency Planning and Community Right to Know Act (EPCRA),
companies are required to report the use and/or release of certain hazardous
substances. In 1997 industries reported that 23.85 billion pounds of
hazardous substances were treated, recycled, used for energy production,
disposed of or released to the environment. This act covers only 650 of
the 75,000 chemicals in use in US commerce today and only companies that
manufacture or proce ss more that 25,000 pounds or use more than 10,000
pounds of a listed substance are required to report.
Companies traditionally have viewed
environmental regulations with disdain and as an economic hardship.
In order to comply with environmental regulations it is estimated to cost
U.S. industries between $100 to 150 billion per year. Since the EPA is charged
with the implementation and enforcement of these laws, the relationship
between industry and the EPA has been adversarial and one of mistrust.
In the last decade a new paradigm
has emerged at the EPA, ushered in, in part by the Pollution
Prevention Act of 1990. This is the first and only act that is
focused on pollution prevention rather than the typical treatment and remediation.
The EPA is now attempting to partner with industry to find more flexible
and cost effective ways of not only meeting exi sting regulations but also
preventing pollution at the source. In 1991 green chemistry became a
formal focus of EPA (green chemistry
at EPA). Green Chemistry or environmentally benign chemistry
is the design of chemical products and processes that reduce of eliminate
the use and generation of hazardous substances .1 Thus instead of limiting Risk by
control ling our Exposure to hazardous chemicals, green chemistry attempts
to reduce and preferentially eliminate the Hazard thus negating the necessity
to control Exposure. The bottom line is, if we don't use or produce
hazardous substances then the Risk is zero, and we don't not have to worry
about the treatment of hazardous substances or limiting our exposure to
Green chemistry has gained a strong
foothold in the areas of research and development in both industry and academia.
Several conferences and meetings (e.g. the Green Chemistry
and Engineering Conference) are held each year with green chemistry/technology
as their focus. The journal Green Chemistry
made it debut in 1999, the Green
Chemistry Institute was recently created and the Presidential Green Chemistry
Challenge Awards were established in 1995.
THE PRESIDENTIAL GREEN CHEMISTRY
The Presidential Green
Chemistry Challenge Awards were announced in 1995 by the Clinton administration
and the first awards were presented in 1996. These awards are a means
of recognizing outstanding achievements in applied green chemistry/technology
and are the only awards in chemistry given out on the presidential level.
Nominees for these awards must demonstrate how their work has met one or
more of the following criteria:
Examples of green chemistry/technology that
have been developed encompass most all areas of chemistry including organic,
biochemistry, inorganic, polymer, toxicology, environmental, physical, industrial
etc. Some cases of green chemistry/technology that have won the Presidential
Green Chemistry Challenge Award consist of (see links to abstracts for these
awards at http://www.epa.gov/greenchemistry/pubs/pgcc/past.html
- Greener reaction conditions for an old synthesis
(e.g., replacement of an organic solvent with water or the use of no solvent
- A greener synthesis for an old chemical (e.g., a
synthesis which us es biomass rather than petrochemical feedstocks or the
use of catalytic rather than stoichiometric reagents).
- The synthesis of a new compound that is less toxic
but has the same desirable properties as an existing compound (e.g., a new
pesticide that is toxic only to target organisms and biodegrades to environmentally
THE TWELVE PRINCIPLES OF GREEN CHEMISTRY1
- Barry Trost's concept of atom economy
which looks at utilized and wasted atoms in a reaction.
- A new synthesis of ibuprofen
which has a much better record of atom economy and pollution prevention.
- The use of waste carbon dioxide
as a blowing agent (which is non ozone depleting unlike the traditional
CFC blowing agents) for foam polystyrene.
- Development of surfactants for carbon
dioxide enabling CO2 to be used as a solvent (for example in dry cleaning).
- Development of oxidant activators for
hydrogen peroxide. This allows, for example, the replacement of
chlorine containing (ozone depleting) bleaches with hydrogen peroxide
in the manufacture of paper.
- The develop ment of new insecticides
that are more specific to target organisms.
Anastas and Warner have developed the
Twelve Principles of Green Chemistry to aid one in assessing how green a
chemical, a reaction or a process is.
1. It is better to prevent
waste than to treat or clean up waste after it is
2. Synthetic methods should
be designed to maximize the incorporation
of all materials used in the process into the final product.
3. Wherever practicable,
synthetic methodologies should be designed to
use and generate substances that possess little or no toxicity to
health and the environment.
4. Chemical products should
be designed to preserve efficacy of function
while reducing toxicity .
5. The use of auxiliary
substances (e.g. solvents, separation agents, etc.)
should be made unnecessary whenever possible and, innocuous
6. Energy requirements
should be recognized for their environmental and
economic impacts and should be minimized. Synthetic methods
should be conducted at ambient temperature and pressure.
7. A raw material feedstock
should be renewable rather than depleting
whenever technically and economically practical.
derivatization (blocking group, protection/deprotection,
temporary modification of physical/chemical processes) should be
avoided whenever possible.
9. Catalytic reagents
(as selective as possible) are superior to
10. Chemical products
should be designed so that at the end of their
function they do not persist in the environment and break down
innocuous degradation products.
11. Analytical methodologies
ne ed to be further developed to allow for
real-time in-process monitoring and control prior to the formation
of hazardous substances.
12. Substances and the
form of a substance used in a chemical process
should chosen so as to minimize the potential for chemical
including releases, explosions, and fires.
EXPOSING STUDENTS TO GREEN
Daryle Busch, former president of the American Chemical Society said "Green
chemistry represents the pillars that hold up our sustainable future. It
is imperative to teach the value of green chemistry to tomorrow's chemists.”
It is clear that many industries and
the research of many academics recognize the significance of green chemistry.
However very little discussion of green chemistry has found its way into
the chemistry curriculum. Although we
and others2 have made some isolated attempts
to bring green chemistry into the classroom, the EPA and ACS have recognized
the need to make a concerted and sustained effort to green the curriculum
so that future chemists are taught to “think green.” The EPA/ACS Green
Chemistry Educational Materials Development Project was begun at a workshop
in October 1998. The thrust of this project is to develop materials
that will aid in the infusion of green chemistry into the curriculum.
The major foci of this project are the development of an Annotated Bibliography
of Green Chemistry, Green Chemistry Laboratory Experiments, Real-World
Cases in Green Chemistry and short courses on green chemistry. John
Warner of U. Mass. Boston is in charge of the first two projects and the
third is a project accomplished by Michael Cann and
Marc Connelly of the University of Scranton.
Cases in Green Chemistry was published in March of 2000. This work,
which is published by ACS, is an attempt to compile and edit information on
green chemistry so that chemistry instructors may use this information to
green the chemistry curriculum at their institution. Each case focuses
on a Presidential Green Chemistry Challenge award winner or nominee.
In order to take the greening of the
chemistry curriculum to its next logical step we are developing green chemistry
modules for insertion of green chemistry into specific chemistry courses.
These modules are being developed by instructors who teach these courses.
The introduction to green chemistry that you are now reading is part of this
1. What do the first eleven major environmental
laws have in common? How does this contrast with the Pollution Prevention
Act of 1990?
2. What are the three criteria for the Presidential
Green Chemistry Challenge Award?
3. Define green chemistry.
4. Which of the Twelve Principles of Green Chemistry
deals with atom economy?
5. In a chemical reaction what is meant by an auxiliary
substance? Look up an example of an organic lab that you have done
and list the auxiliary substances that you used.
6. Why are catalytic reagents superior to stoichiometric
reagents (in your answer make sure that you explain the terms catalytic and
7. What is the Toxic
8. Consider a chemical product or process that you
are aware of. With the Twelve Principles of Green Chemistry as your
guide devise ways to make this product or process greener.
1. Anastas, Paul T., and Warner, John C. Green Chemistry
Theory and Practice, Oxford University Press, New York, 1998.
2. a) http://jchemed.chem.wisc.edu/Journal/Issues/1995/Nov/abs965.html
b) Teaching green chemistry, Albert
Matlack, Green Chemistry, 1999, 1
Please direct comments, suggestions and requests
for hard copies of the modules to: Michael C. Cann
Chemistry Depart ment
University of Scranton
Scranton, PA 18510