Why Recycle?
A teacher’s guide to
recycling education in the classroom
Brought to you by
Why Recycle?
A teacher’s guide to recycling education in the classroom
Introduction......3
What is Garbage? .....4
Importance of Recycling ....5
Aluminum .......6
Tin/Steel .......7
Plastics .......8
Glass .......9
Paper .......10
Beyond Recycling .....11
“Never doubt that a small group of thoughtful, committed citizens can
change the world; indeed it’s the only thing that every has.” ~Margaret
Mead, 1901-1978
Welcome to “Why Recycle? - A Teacher’s Guide to Recycling Education in the
Classroom.” Greenstar is proud to offer this complimentary guide to all interested
educators. In addition to background information on the solid waste and recycling
industry this resource describes five recyclable commodities: aluminum, steel, plastic,
glass and paper. The guide provides the following for each material: an overview,
material composition, recycling process, statistics (“fast facts”) and subject application
(“curriculum corner”).
Greenstar understands its role in and the importance of education with respect to
environmental stewardship. The company sees the value of working together and
reaching out to everyone to help them understand that individuals really can make a
difference.
Many of our locations offer unique tours for hundreds of school children throughout
the year in order to foster environmentally sustainable behaviors for generations to
come. In addition to offering facility tours, Greenstar hosts, sponsors and participates
in countless local events, reinforcing the company’s commitment and dedication to
community involvement.
For more information on school tours, educational materials and sponsorships please
visit www.GreenstarRecycling.com.
What is Garbage?
Municipal Solid Waste (MSW)—more commonly known as trash or garbage—consists of everyday items such
as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, paint
and batteries. In 2006, US residents, businesses, and institutions produced more than 251 million tons of MSW,
which is approximately 4.6 pounds of waste per person per
day. Americans use by far the most resources per capita in the
world. The average American consumes nearly 20 times more
than the average citizen of Mexico and hundreds of times more
than an average Ethiopian. In fact, if everybody used as many
resources as Americans, we’d need more than 5 planets to
sustain ourselves.
These charts show how much waste we generate (prior to
recycling) and
what percentage of common materials are recycled. Notice that
paper, plastics and metals comprise over half of all materials
generated. These three items are easily recyclable and most
communities already offer recycling services for them.
There are many things we can do to properly manage, prevent or
divert the waste we create. Source reduction involves altering the
design, manufacture or use of products and materials to reduce
the amount and toxicity of what gets thrown away. Recycling
diverts items, such as paper, glass, plastic and metals, from the waste stream. These materials are sorted, collected
and processed and then manufactured, sold and bought as new products. Composting decomposes organic waste,
such as food scraps and yard trimmings, with microorganisms (mainly bacteria and fungi), producing a humus-like
substance.
The EPA has ranked the most environmentally sound strategies for MSW. Source reduction (including reuse) is
the most preferred method, followed by recycling and composting, and, lastly, disposal in combustion facilities
and landfills. Currently, in the United States, 32.5% is recovered and recycled or composted, 12.5% is burned at
combustion facilities, and the remaining 55% is disposed of in landfills.
Importance of Recycling
Recycling, including composting, diverted 82 million tons of material away from disposal in 2006, up from 15
million tons in 1980. As a whole, Americans recycle or compost about 1/3 of their waste. Typical materials
that are recycled include batteries, recycled at a rate of 99%, paper and paperboard at 52%, and yard
trimmings at 62%. These materials and others may be recycled through curbside programs, drop-off centers,
buy-back programs and deposit systems.
Curbside Program
Deposit System
Drop-Off Center
Once the materials are gathered using these various systems, they are most often transported using large
packer trucks and semi-trucks to a recycling processing center. At the recycling center, the materials go
through a variety of processing, including sorting, shredding, crushing, cleaning and baling to prepare them
for the manufacturing mills. These mills are usually specialized to one type of recyclable – i.e. a paper mill
or a glass processing facility – where the materials are further processed into new products (also known as
end-products) for consumers to purchase.
These materials have been processed and are ready to ship to mills. L to R: Cardboard, glass, plastic and aluminum cans.
The chasing arrows so closely aligned with recycling are called the Mobius Loop. The
three arrows represent the steps in the recycling process: collect, reprocess and reuse.
The last step is most important part of the process: ensuring that consumers buy
the item made with recycled material, also called a recycled content product. Look
closely at labels when you shop to make sure you’re selecting products made with
recycled materials.
There are several benefits associated with recycling. Recycling prevents the emission
of many greenhouse gases affecting global climate, prevents release of several air and water pollutants,
saves energy, supplies valuable raw materials to industry, creates jobs, stimulates the development of
greener technologies, conserves resources for our children’s future and reduces the need for new landfills
and combustors.
Aluminum
Ninety-five percent of all beer and soft drink cans in the United States are made of aluminum. American canmakers produce about 100 billion aluminum beverage cans a year, equivalent to one can per American per day.
While almost all food cans are made of steel, aluminum’s unique properties make it ideal for holding carbonated
beverages.
The raw material of the aluminum beverage can is, of course, aluminum. Aluminum is derived from an
ore called bauxite, which is a nonrenewable resource. The bauxite is refined and then smelted, and the
resulting molten aluminum is cast into ingots. A large portion of the aluminum used in the beverage
can industry is derived from recycled material. The average aluminum cans contains approximately 51%
recycled material.
Using aluminum cans to make new aluminum cans saves 95% of the energy needed to make the
cans directly from the bauxite ore. That means you can make 20 cans out of recycled material with
the same energy it takes to make one can out of new material
Fast Facts:
• The aluminum beverage can returns to the grocer’s shelf as a new, filled can in as little as 60 days after
collection. That means a consumer could purchase basically the same recycled aluminum can from a grocer’s
shelf approximately every 9 weeks, or 6 times a year
• While aluminum cans are typically recycled into more aluminum cans, they can also be used to manufacture
window frames, highway signs, storm doors, pie plates, thumbtacks and license plates
• Americans throw away enough aluminum every three months to rebuild our entire commercial air fleet
• Recycling just one aluminum can saves enough energy to run a television for 3 hours
• Recycling 1 ton of aluminum cans saves enough energy to power 950 computers or TVs for a week or 120 100watt light bulbs for a week (approximately 10 homes)
• One ton of recycled aluminum saves 14,000 Kwh of energy, 40 barrels (1,663 gallons) of oil, 238 million Btu’s
of energy and 10 cubic yards of landfill space
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Curriculum
Math
The first beverage can, filled by a brewer in Newark, New Jersey in 1935, weighed three ounces. Today, an aluminum beverage
can weighs one-half ounce — 600% less than the original beverage can.
Math Question #1: How many aluminum beverage cans does it take to equal one pound?
Math Question #2: The average bale of aluminum beverage cans weighs 1,000 pounds. How many cans on average are in one
bale?
Math Question #3: A full truckload of aluminum headed to the mill for reprocessing contains approximately 43 bales. How
many cans are in each truckload?
Answers: 1. 32 cans 2. 32,000 cans 3. 1,376,000 cans
Tin & Steel
Steel is a part of our daily life even if you don’t realize it. Steel cans package a wide variety of products including
fruits, vegetables, soups, sauces, meats, juice, pet food, cleaning products, shoe polish, paint and coffee. Oftentimes
called “tin cans,” these containers are actually 99% steel, with a thin layer of tin added to prevent rusting.
The recycling process for steel cans is similar to that of aluminum. At the recycling processing
facility, magnets are used to separate steel cans from other recyclables. The steel cans are then
crushed into large cubes called bales and shipped to steel mills or foundries for recycling. Steel
cans are combined with other steel scrap and melted in a furnace to make new steel for new
steel products. Basic oxygen steel furnaces can use 28% scrap steel as feed stock while electric
arc furnaces can use up to 100% scrap steel.
Like aluminum, steel can be recycled over and over without wearing out. More than twothirds of the amount of steel produced each year is recycled, making steel the most actively
recycled material. Recycled steel cans are used to make new steel products including steel cans,
automobiles, bridges, appliances and construction materials.
Using old steel to make new steel has many environmental benefits including landfill conservation, natural
resource and energy preservation and reduced pollution. Recycling steel cans saves 74% of the energy used
to produce them from raw materials. Scrap steel reduces related water pollution, air pollution, and mining
wastes by about 70%. For every ton of steel recycled, 2500 pounds of iron ore, 1400 pounds of coal
and 120 pounds of limestone are conserved. And in a year, the steel industry conserves the equivalent
energy to power about 18 million homes for 12 months.
Fast Facts:
• Americans use 100 million tin and steel cans every day, enough to make a steel pipe running from
Los Angeles to New York and back again daily
• We throw away enough steel every year to build all the new cars made in America
• Recycling one pound of steel conserves enough energy to light a 60-watt light bulb for 26 hours (5,450 BTU)
(Approximately 7 cat food cans or 4 dog food cans = 1 pound)
• More than 28% of the average new steel can consists of recycled steel
• The steel industry recycles nearly 19 billion steel cans into new products, equating to 600 steel cans being
recycled every second
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PR/Marketing
Steel and iron components make up nearly 65% of the average automotive vehicle. The steel used in car bodies is made with
a minimum of 25% recycled steel, and many internal automotive parts, such as engine blocks, are made using even higher
percentages of recycled steel.
Marketing Question: What car manufacturers are promoting the recycled content usage in their automobiles?
Marketing Project: Design an advertising/marketing campaign to promote not only the recycled content used in vehicles,
but also the environmental benefits from using recycled steel. Be sure to include the answer to WIIFM (What’s in it for me?) to
engage consumers in the recycling process.
Plastic
Plastic plays an integral role in our lives as an affordable yet sturdy material for many of the items we use every day.
Plastic is one form of polymers that are composed of a long chain of smaller molecules known as monomers. Monomers
themselves are made of atoms that are usually extracted from natural or organic substances, and are generally classified
as petrochemicals. All sorts of monomers can be utilized in the creation of plastic. Plastics are mostly made from
petroleum (oil).
There are thousands of plastics, but many plastic consumer
containers can be categorized using the #1 - #7 classification
system. Simply look at the bottom of a container for the
recycling mobius—the number inside the arrows tells the type
of plastic.
#
Type
Common Usage
1
PET/PETE
Soft Drink, Mouthwash and Peanut Butter Containers
2
HDPE
Milk, Shampoo and Detergent Containers; Grocery Bags
3
PVC
Packaging, Cable Insulation, Construction Products
4
LDPE
Stretch/Shrink Wrap; Redemption Bags
5
PP
Yogurt, Margarine and Medicine Containers
6
PS
Egg Cartons, Styrofoam Cups/Plates
All of these seven types can be recycled if you find the right
market. The order of most to least commonly
recycled is PETE, HDPE, LDPE, PP, PVC, PS and Other. HDPE and PET bottles show the highest recycling rates
of any plastic bottles types, at 23.8% and 22.8% respectively.
Plastics are recycled using several techniques including sorting, code-separating, cleaning, granulating,
pelletizing, flaking, melting and spinning. Plastics are not typically recycled into more food containers, but
instead make a wide variety of consumer products. PET is most commonly used in carpeting, clothing and
strapping. HDPE is recycled into new non-food containers, plastic piping, lawn and garden products, plastic
lumber and injection molding products (i.e. buckets, crates and automobile parts).
Fast Facts:
• Americans use 2.5 million plastic bottles every hour
• Recycling 1 ton of plastic milk jugs saves enough energy to light a home for approximately 1 year (10,000 plastic
milk jugs = 1 ton)
• Since 1990, plastic bottle recycling has increased six-fold
• PET & HDPE accounted for more than 99% of the 1.45 billion pounds of bottles recycled. The two resins also
accounted for more than 94% of all resins used in the production of plastic bottles during 1998
• Five PET bottles yield enough fiber to make an extra large T-shirt.
• It takes 35 two-liter PET bottles to produce enough fiberfill for a sleeping bag
Curriculum Corner
Chemistry & Writing
Chemistry (Older Students)
Plastics have a chemical property known as permeability, meaning it has the ability to absorb and/or take on the qualities of what is
contained inside the plastic container. Can you think of an example? A ketchup bottle smelling like ketchup after being thoroughly
rinsed. How is our skin like plastics? Skin absorbs lotion applied to it; you cannot remove the lotion later. Why is this an important fact
to know? Plastics previously containing a dangerous substance should not be recycled into something that holds a food product. For
example, a plastic container holding motor oil should never be recycled into a drink container - in fact, it shouldn’t be recycled at all!
Writing (Younger Students)
Grammar, penmanship and communication are all very important skills. Have your students practice these as they write a letter to a
company that uses/manufactures plastics to thank them for recycling and/or to ask them to do more to recycle.
Example: A school in Des Moines, Iowa wrote to Heinz Ketchup asking them to use either a #1 or #2 plastic for their ketchup bottles
since a #5 plastic was not recyclable in their area. Heinz responded to them personally and shipped only #1 and #2 bottles to the Des
Moines market area.
Glass
Glass is the oldest form of recycled material, produced by the Egyptians in 12,000 B.C. for jewelry and drinking cups.
Glass can be recycled again and again with no loss in quality or purity.
In 2005, glass made up 5.2% of the municipal solid waste stream by weight, and 25.3% of those glass containers
were recycled. In many recycling programs, glass must be separated by color, usually into flint (clear), green and
amber (brown). Before recycling glass, make sure that it is a container and is contaminant-free. Keep out noncontainer glass and metals, such as ceramic cups/plates/pottery, laboratory glass, drinking glasses, mirrors, light
bulbs, metal caps/lids/neck rings.
Recycled glass is turned into “cullet,” which is furnace-ready scrap glass, through a cleaning and crushing process.
Paper labels and metal lids are removed with a vacuum and magnet respectively. The containers are then crushed
into pea-sized pieces. This cullet is then mixed, or “batched,” with silica, sand, soda ash and limestone – with up
to 70% of the mixture being recycled glass. These combined materials are then heated to a temperature of 2600 to
2800 degrees Fahrenheit and molded into the desired shape.
Recycled glass is used for new glass containers, fiberglass insulation, road beds (aggregate), concrete block and
glassphalt (asphalt). Manufacturers benefit from recycling in several ways - it reduces emissions and consumption of
raw materials, extends the life of plant equipment, such as furnaces, and saves energy.
Fast Facts:
• As late as 1947, virtually 100% of all beverage bottles were returnable
• The average American can save six pounds of glass in a month
• Every day, Americans recycle about 13 million glass jars and bottles
• All newly purchased glass food jars contain at least 35% recycled glass
• Recycling one glass bottle saves enough energy to light a 100-watt bulb for 4 hours
• Making glass from recycled materials cuts related air pollution 20%, water pollution 50% and mining waste 75%
• We save over a ton of resources for every ton of glass recycled -- 1,330 pounds of sand, 433 pounds of soda ash,
433 pounds of limestone and 151 pounds of feldspar
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Curriculu
Cultural Anthropology
Why did Egyptians choose gold for jewelry when they had so many other precious gems available?
Egyptians considered glass to be in the same league as precious gems and metals, that the process of creating glass stimulated
special and priceless magical powers.
What significance did the jewelry hold? Why was ornamentation so important? The ancient Egyptians loved ornamentation.
In their typical holistic fashion, fine jewelry was valued not only for beauty but also for the magical and spiritual protection it
provided for its wearer. Egypt utilized many resources from the environment to create a distinctive culture.
Encourage your students to learn more about the culture of Egypt:
Significance of Glass Beads/Jewelry: http://www.egyptmonth.com/mag4.htm
Ancient Egyptian Culture: http://www.mnsu.edu/emuseum/prehistory/egypt/index.html
Life in Ancient Egypt: http://www.watson.org/~leigh/egypt.html
The average American uses 650 pounds of paper per year. Paper, which is primarily made from trees, is 40% of all
that we throw away. In 2005, a record 51.5% of the paper consumed in the U.S. (51.3 million tons) was recovered
for recycling. That’s a high recycling rate compared to some other materials, but we’re still throwing away nearly
half of all recyclable paper.
All paper (i.e. fiber) is recyclable, but not indefinitely. Individual fibers become too short after about 6 times through
the recycling process. During the recycling process, which can be likened to doing laundry with water, detergents
and driers, paper is shredded & mixed with water to make pulp. Pulp is washed, refined and cleaned, then turned
to slush in a beater. Color dyes, coatings and other additives are mixed in, and the pulp slush is pumped onto
a large moving screen. As the pulp travels down the screen, water is drained away and recycled. The resulting
paper sheet, also known as web, is pressed between massive rollers to extract most of the remaining water and to
ensure smoothness and uniform thickness. The semi-dry web is then run through heated dryer rollers to remove any
remaining water. The finished paper is then wound into large rolls, which can be 30 feet wide and weigh close to 25
tons. A slitter cuts the paper into smaller, more manageable rolls, and the paper is ready for use.
Recycled paper is turned into a wide variety of products. Cardboard will most likely be used to make more
cardboard and paperboard (cereal and shoe boxes). Newspaper is usually made into new newspaper, but can also
be used for egg cartons, paperboard and building insulation. Other types of paper including printing paper, junk
mail and magazines can return to us as more paper, paperboard, tissue, paper towels and napkins.
Fast Facts:
• Each ton of recycled paper saves an estimated 17 trees, 4100 kilowatt hours of energy, 7000 gallons of water, 60
pounds of air pollution and 3.3 cubic yards of landfill space
• The average office worker produces 1.5 pounds of waste each day while work. Of that, 1/3 is 100% recyclable
paper products
• Each and every day, Americans recover well over 2 million pounds of paper
• More than 1/3 of the fiber used to make paper products is made from recycled paper
• It takes 75,000 trees to print a Sunday Edition of the New York Times
• Americans throw away enough office and writing paper annually to build a wall 12 feet high stretching from Los
Angeles to New York City
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Curriculu
History
Did you know that paper was first used in 3,000 B.C.? Paper, whose name is derived from papyrus, in its earliest form was made
mostly from the inner bark of paper mulberry, fig and daphne.
When did the first paper mill open in the U.S.? England began making large supplies of paper in the late 15th century and
supplied the colonies with paper for many years. It wasn’t until 1690 that the first U.S. paper mill was built.
Encourage your students to learn more about the history of paper:
www.paperrecycles.org/paper_environment
www.paperonline.org/history/history_frame.html
Beyond Recycling
1. Buy products made from recycled material.
The loop doesn’t close unless consumers
purchase the new products made of the
materials they recycled. Look for the recycling
symbol and a message like “this product
contains 100% recycled material.”
2. Precycle. As you’re shopping, look for
unnecessary packaging. Examples include
a cardboard-backed packaged with a seethrough plastic face and single-serving
packs like chips, puddings and applesauce.
Buy refillable/reusable containers and then
purchase items in bulk to save packaging and money!
you will get more light for less money, save a
lot of electricity and reduce carbon emissions.
Face it, no one likes to switch out light bulbs,
and with CFLs, you only have to do it once
every 5-10 years!
7. Stop Unwanted Catalogs & Junk Mail! Spend
10 minutes a week calling to request that your
name be removed from catalog mailing lists.
Requesting your name to be removed from
junk mail lists at www.DMAConsumers.org
protects you for 5 years!
8. Create a compost pile. Find a corner of the
yard that’s out of the way. Carefully throw
food wastes (leftovers, eggshells, coffee
3. Use canvas bags. Say ‘neither’ the next time
grounds, spoiled vegetables, etc.) into a pile
you’re asked ‘paper or plastic.’ Both paper
and mix with dirt. Every week, turn the pile
and plastic bags create a lot of pollution and
over with a shovel to give it more air. In a few
waste. Bring canvas or mesh bags that can be
weeks, it will turn into rich, nutritious soil to
used over and over.
help plants grow.
4. Buy local, organic and read the labels. There’s 9. Shop at second-hand stores. Donate your old
more than calorie information on those labels.
toys so that someone else can enjoy them.
Typically, the fewer ingredients listed, the
Shop for clothing and gently used items at
more natural the product. Support your local
thrift stores. You can reuse what’s already
farmer’s market where the food is fresh, uses
there and help support local businesses.
fewer chemicals and hasn’t traveled many
miles to get to you.
10.Cancel your book club, magazine and
newspaper subscriptions. Use the copies at
5. Keep the car at home. Automobiles are
your local library or search for the information
among the largest contributors to pollution.
online.
For short trips, encourage your family to
11.Avoid fast food. The fast food industry creates
walk, bike, roller-skate or take the bus. You’ll
tons of waste. While convenient, it will never
have great bonding time while enjoying the
come close to a home-cooked meal. Take a
outdoors.
few more minutes to make meals yourself.
6. Change a light bulb. By changing a standard
Eating in saves money and keeps you
bulb with a compact fluorescent light bulb,
Greenstar would like to give a special
thank you to all educators. You help
make the world a better place!