Introduction to Green
Chemistry
IN4GC Teaching Resources
Prepared by Isla Milne
Outline
• Why do chemicals matter?
• The problem: Global chemical exposure and contamination
• The (partial) solution: Green chemistry
– 12 principles
• Green chemistry in action: Case studies
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Greener synthesis of ibuprofen
Dry cleaning without Perc
Boat paint without tin
Plastics from renewable sources (NatureWorks)
• Role of business in green chemistry
• Drivers for green chemistry: Business case for green chemistry
– Ambec and Lanoie, 2008, Reinhardt, 1999
– EVA of 12 principles
• Barriers to green chemistry
• Conclusion
Why do chemicals matter? Chemicals and
chemistry are everywhere
Chemistry is life!
C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy
Why do chemicals matter? Chemicals and
chemistry are everywhere
Chemistry is life!
Why do chemicals matter? Chemicals and
chemistry are everywhere
• Chemicals are the “molecular building blocks” of our
economy
• Daily U.S. Chemical production and importation: 74
billion lbs
• 82,000 chemical substances and millions of products
in circulation
Why do chemicals matter? Global chemical
production is growing rapidly
• The chemical industry is valued at ~4 trillion USD (OECD, 2011)
Blue Jean Life Cycle Assessment:
where/how are chemicals used?
• Work in groups of 2 or three
• Consider a pair of blue jeans. Brainstorm all
of the places in the product life cycle where
chemicals would be used
• Pair up with another group and compare
answers.
• Report back to the class and discuss
• What are the hazards associated with the
chemicals identified in the lifecycle?
Chemicals: Double edged sword
They are the solution to many
of our problems....
But the cause of many hazards
as well...
The problem: Global chemical
contamination
• Chemical pollution in the environment: The “environment” is
not somewhere “out there”. We live in our environment
• Synthetic chemicals contribute to a wide range of
environmental and health hazards
Cancer
Neurodevelopmental problems
Obesity
Reproductive anomalies or
dysfunction
Asthma and allergies
Neurodegenerative problems
Immune dysfunction
Climate change
Eutrophication
Biodiversity loss
Air pollution
Ozone depletion
Etc...huge data gaps!!
~700 new chemicals introduced into the market each year
Chemical contamination: From disasters in the
chemical industry...
In 1976, a chemical plant in Sevesco,
Italy that manufactured pesticides and
herbicides released a dense cloud of
tetrachlorodibenzoparadioxin (TCDD),
contaminating tens square miles of land.
2000 people were treated for dioxin
poisoning.
In 1984, a methylisocyanate leak at a
Union Carbide chemical plant in
Bhopal, India, killed thousands of
people
...and from gradual chemical pollution and
exposure to everyday products
• Examples:
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Flame retardants
Cosmetics
Cleaning products
Paint
Plastics
Chemical contamination: Evidence from
biomonitoring
Chemicals found in pregnant women, umbilical cord blood,
and breast milk:
Mercury
PCBs
Flame retardants (e.g. PBDEs)
Solvents
Phenols (e.g. Bisphenol A)
Stain repellants (e.g. Perfluorinated surfacants)
Dioxins (e.g. TCDD)
Perchlorate
Plasticizers (e.g. Phthalates)
Furans (e.g. TCDF)
Polycyclic Aromatic Hydrocarbons (PAHs)
Organochlorine pesticides (e.g. DDT, Hexachlorobenzene)
Woodruff T. et al, 2011 Environ Health Persp.; Needham L. 2010 et al, Environme Sci Tochnol
Lakind, J.S. Et al, 2004 Toxicol Appl Pharma. Modified from the Berkeley Center for Green Chemistry slides.
Chemical contamination: Evidence from
biomonitoring
287 synthetic chemical pollutants
detected in umbilical cord blood
Mercury
Polyaromatic hydrocarbons (9)
Polybrominated dibenzodioxins and furans (7)
Perfluorinated chemicals (9)
Polychlorinated dibenzodioxins and furans (11)
Organochlorine pesticides (21)
Polybrominated diphenyl ethers (32)
Polychlorinated napthalenes (50)
Polychlorinated biphenyls (147)
Modified from the Berkeley Center for Green Chemistry slides.
Problem: Global chemical contamination
Solution: Green chemistry!
• Green chemistry (sometimes called “sustainable chemistry”) is a design
strategy. It aims to prevent problems rather than clean them up later
• Definition: “Design of chemical products and processes that reduce and eliminate
the use and generation of hazardous substances” (Anastas and Warner, 1998)
Risk = f(Hazard, Exposure)
•
Green chemistry is a RADICAL approach as the institutionalized and industrially
embedded approach is to focus on exposure reduction. Green chemistry focuses
on reducing the hazard.
Video (2:31min): Martin Poliakoff on green chemistry: http://www.youtube.com/watch?v=_KYiLFkMQ_E
Key elements in a chemical Products:
process
Desired
products and unwanted
by-products
Feedstock: starting
material
Energy: Energy used to
make reaction work,
heating etc
Medium and reagents:
Where is the reaction
happening? What needs to
be added for the reaction
to occur?
How can we make this process greener??
Adapted from presentation by Dr. Audrey Moores
Two different kinds of chemical plants...
12 principles of green chemistry
1. PREVENTION: It’s better and easier to prevent waste than to deal with
it after it’s formed.
2. ATOM ECONOMY: We should maximize the amount of material inputs
that get incorporated into the final product.
3. LESS HAZARDOUS SYNTHESES: We should minimize hazardous
by-products created by syntheses.
4. SAFER CHEMICALS: We should use design to preserve the efficacy of a
function while reducing its toxicity.
Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice, Oxfor University press, 1998
12 principles of green chemistry
5. SAFER SOLVENTS AND AUXILIARIES: We should minimize the use
of auxiliary substances wherever possible, or use ones that are nontoxic.
6. ENERGY EFFICIENCY: Energy requirements have environmental and
economic impacts. We should conduct syntheses at ambient temperature
and pressure to minimize energy costs.
7. RENEWABLE FEEDSTOCKS: Use renewable feedstocks
8. REDUCE DERIVATIVES: Unnecessary derivatization (using protecting
or blocking groups during synthesis) should be avoided whenever possible
to reduce waste. Minimise the number of steps in the reaction.
Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice, Oxfor University press, 1998
12 principles of green chemistry
9. CATALYSIS: Catalytic reagents are better than stoichiometric reagents in
that they allow for lower temperatures and energy costs, and are reusable
and therefore generate less waste.
10. DESIGN FOR DEGRADATION: Design products that are
biodegradable at the end of their use.
11. REAL TIME POLLUTION PREVENTION: We should encourage
methodologies to monitor the process of a reaction so as to detect the
emergence of toxic by-products.
12. ACCIDENT PREVENTION: By minimizing the use of toxic substances
and high energy processes, we also minimize the potential for
Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice, Oxfor University press, 1998
Greening a chemical process
Feedstocks
•Use renewable
feedstocks
• Maximize the amount
of inputs that make it
into final product
Catalysts
•play on activation
energy and do more
with less
Energy
•Use less
Energy
•Conduct reactions at low
temperature and pressure
Products and byproducts
•Minimize waste
•Produce byproducts and
products that are less toxic
and biodegradable
Synthesis design
•Minimize number of steps
in reaction
Medium and reagents
•Conduct reaction in
water if possible
• Use safer solvents
12 principles of green chemistry
• GreenER. Not “green”. It’s all relative. There is
no reaction in the world that would not have
some impact - strive for continuous
improvement.
• Not all of the 12 principles will be addressed
at the same time: there may be tradeoffs.
Green Chemistry in action: Ibuprofen
• Developed by BHC (now part of BASF)
in 1990s, the green route for Ibuprofen
production produces more ibuprofen in
less time and using less energy than the
original process. This means cheaper
products for the consumer with increased
profits for the manufacturers. It saves
20,000 of waste/year!
Original Route
Green Route
6 steps
3 steps
Stoichiometric reaction
• Large amounts of aluminum
tricholoride used
Catalysts (recyclable!)
• Smaller amounts of hydrofluoric acid
used
Atom economy: 40% (60% of inputs
end up in waste stream)
Atom Ecomony: 77%
Poliakoff, M., 2007
Greening the ibuprofen process
Feedstocks
Maximize the amount
of inputs that make it
into final product
(Atom economy =
77%)
Energy
•Use less
Energy
Catalysts
•play on activation
energy and do more
with less
Synthesis design
•Minimize number of steps
in reaction (3 vs. 6)
Medium and reagents
Products and
byproducts
•Minimize waste (Less
hydrofluoric acid used)
Green chemistry in action: Dry
cleaning without Perc
• Dry cleaning industry is heavily dependent on solvents (dry cleaning is not
really dry!), 100,00 dry cleaners worldwide use percholorethylyne (perc)
as primary solvent
• Perc is toxic: everything perc comes in contact with must be handled as
“hazardous waste” except the dry cleaned clothes
• Supercritical carbon dioxide has been developed and demonstrated as a
viable alternative
• It is non-toxic, biodegredable, and avoids costly waste disposal and
regulatory compliance
• It has been shown to outperform perc in dry-cleaning applications
Manley et al 2007.
Greening the dry cleaning process
Feedstocks
Products and byproducts
•Minimize waste
•Produce byproducts and
products that are less toxic and
biodegradable
Synthesis design
Medium and reagents
Energy
Green chemistry in action:
Boat paint without tin
• Tribytyltin (TBT) was widely used as an antifoulant on boats. It worked by
gradually leaching from the hull killing the fouling organism in the surrounding
area
• It is extremely toxic to aquatic life, is an endocrine disrupting chemical, and
very persistent in the environment
• Regulations now restrict the use of TBT (e.g. banned in EU)
• Rohm and Haas have developed an alternative based on thiazolone chemistry,
which works by creating a hostile growing environment
• New product is free of heavy metals, showed no chronic or reproductive
toxicity to marine species, degrades readily when released into the
environment
Manley et al 2007.
Greening boat paint
Feedstocks
Products and byproducts
•Produce byproducts and
products that are less toxic and
biodegradable
Synthesis design
Medium and reagents
Energy
Green Chemistry in Action: Plastics
from renewable material
• NatureWorks biobased plastic resins: Joint venture between Cargill Inc and
Dow Chemical
• Received Presidential Green Chemistry Challenge Award in 2002
• Developed the first synthetic polymer class to be produced from
renewable resources (corn), a potential substitute for petroleum-based
polymers
• Biodegradable (compostable)
• Manufacturing sequence reduced consumption of fossil fuels by 30%-50%
compared to conventional oil-based plastic resins
Larson et al, 2006, Darden case study
http://www.natureworksllc.com/The-Ingeo-Journey/Eco-Profile-and-LCA/Eco-Profile
Greening the plastic production process
Feedstocks
•Use renewable
feedstocks (corn)
Catalysts
•play on activation
energy and do more
with less (enzymatic
fermentation process)
Products and byproducts
•Produce byproducts and
products that are less toxic
and biodegradable
Synthesis design
Energy
•Use less
energy
Medium and reagents
Many steps in the
reaction are solvent free
How businesses can contribute to the
advancement (or not) of Green Chemistry
Fund and conduct R&D
Manufacture chemicals and products
Sell chemicals and products containing chemicals
Manage supply chains
Lobby for/against regulations
Distribute products containing chemicals
Run marketing campaigns
Conduct take-back initiatives (recovery and recycling)
Influence metrics used to measure performance (is
environmental performance valued?)
• Collaborate (e.g. with academia)
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Drivers for green chemistry: It makes good
business sense!
• Reinhardt 1999
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Differentiating products
Managing your competitors
Saving costs
Managing environmental risks
Redefining markets
• Ambec and Lanoie 2008
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Better access to certain markets
Differentiating products
Selling pollution control technologies
Risk management and relations with external stakeholders
Cost of Materials, Energy and Services
Cost of capital
Cost of Labor
Drivers for green chemistry: Business benefits of
green chemistry innovation
Percentage of innovations
coded
100
90
80
70
60
50
40
30
20
10
0
Policy/regulatory
incentives
Improved
Performance
Cost savings
Risk reduction
• Data set: Nominations for the Presidential Green Chemistry Awards, 2010
• Out of 60 green chemistry innovations coded, ~80% improved performance, ~85%
reduced cost, ~45% reduced risk and ~35% increased regulatory compliance
compared to the incumbent technology
Milne and Maguire, 2011. ACS GCI Green Chemistry conference presentation
Drivers for green chemistry: Rising B2B
demands
“There are rising B2B demands for green chemicals,” says Rich Liroff,
executive director of the Investor Environmental Health. Network. “Nike
is now highlighting preferred green chemicals in its purchasing
requirements. Staples also has developed a list of “bad actor chemicals;”
and quite recently, several Group Purchasing Organizations in the health
care sector, with buying power estimated at roughly $20 billion, developed
a questionnaire for
suppliers that
focused on
various sustainability
questions, including
the presence or absence of
specific chemicals of
concern.”
- Rich Liroff, Environmental Health
Investors Network
Forbes Magazine, 2011, Better profits
through green chemistry
Drivers for green chemistry: market for green
chemicals is growing
Source: Pike Research, 2011, Green chemistry research report
Which of the 12 principles are more likely to
have high Economic Value Added?
1. PREVENTION: It’s better and easier to prevent waste than to deal with it after it’s formed.
2. ATOM ECONOMY: We should maximize the amount of material inputs used in the final product
3. LESS HAZARDOUS SYNTHESES: We should minimize hazardous by-products created by syntheses.
4. SAFER CHEMICALS:We should use design to preserve the efficacy of a function while reducing its
toxicity.
5. SAFER SOLVENTS AND AUXILIARIES: We should minimize the use of auxiliary substances wherever
possible, or use ones that are non-toxic.
6. ENERGY EFFICIENCY: Energy requirements have environmental and economic impacts. We should
conduct syntheses at ambient temperature and pressure to minimize energy costs.
7. RENEWABLE FEEDSTOCKS: Use renewable feedstocks
8. REDUCE DERIVATIVES: Unnecessary derivatization (using protecting or blocking groups during
synthesis) should be avoided whenever possible to reduce waste.
9. CATALYSIS: Catalytic reagents are better than stoichiometric reagents in that they allow for lower
temperatures and energy costs, and are reusable and therefore generate less waste.
10. DESIGN FOR DEGRADATION: Design products that are biodegradable at the end of their use.
11. REAL TIME POLLUTION PREVENTION: We should encourage methodologies to monitor the
process of a reaction so as to detect the emergence of toxic by-products.
12. ACCIDENT PREVENTION: By minimizing the use of toxic substances and high energy processes, we
also minimize the potential fo
Barriers to green chemistry
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Upfront costs (R&D, infrastructure etc)
Uncertainty and risk (regulatory and scientific)
CBI – hard to get suppliers to tell you what is in their products
Data, safety and technology gaps (Wilson and Schwarzman, 2008)
Regulatory barriers
• Regulations are very fragmentation (REACH, TSCA, Chemicals
Management Plan etc)
• How safe is safe? Two models:
(a) Company must produce evidence of safety (e.g. FDA (drugs))  default
assumption is that the chemicals are hazardous
(b) Government must produce evidence of harm (Toxic Substances Control Act,
most other laws)  default assumption is that chemicals are safe
– REACH (EU legislation) is starting to set a good example, moves towards
model (a)
Barriers to green chemistry: Data gaps
“Not enough information is available on how many of the
approximately 30,000 substances currently estimated to be
covered by the REACH proposals have dangerous properties.
[...] However, of the new substances assessed under existing
EU legislation, around 70% have been shown to have one or
more dangerous properties. An unknown but potentially
significant proportion of all chemical substances will enter the
environment and reach sufficiently high concentrations to
induce adverse effects”
European Commission, 2003, REACH Extended Impact Assessment, p27
Barriers to green chemistry: Data gaps
“All substances are poisons: there is no substance which is not a poison. The
right dose differentiates a poison from a remedy”
Paracelsus, 1493-1591
“The dose of the mixture makes the poison, but differently for different
individuals and differently at different times during growth and
development”
Peter Motague, 2002
• Our understanding of what differentiates a “poison from a
remedy” is evolving, but there is still a lot we don’t know
• Traditional methods of testing for toxicology are not
effective for many toxicology endpoints: e.g. Endocrine
disruption
Conclusion
• To be successful, green chemistry requires an interdisciplinary
strategy in education, research and service
– You don’t have to be a chemist or a toxicologist, you just have to know
what you don’t know so you can ask one!
• Green chemistry makes good business sense
• Chemical exposures and global chemical contamination:
– No single problem
– No single solution
– Green Chemistry has the potential to be part of the solution