Questions et réponses sur l’environnement

1. Why do we use single service products?

Meals on Wheels Patient and Nurse in Hospital using foam

Foam, paper, and plastic food products were developed to minimize exposure to bacteria and other foodborne pathogens. As one study concluded, "while these data do not prove that using disposables actually prevents foodborne illness, the fact that reusables have a statistically higher level of microbial contamination than disposables favors the presumption that single service offers a measure of protection that would be missed if solid waste considerations barred them from use" (Felix, Charles W., Chet Parrow, and Tanya Parrow, "Utensil Sanitation: A Microbiological Study of Disposables and Reusables." Journal of Environmental Health September-October 1990: 15.)

Patrons of fast food restaurants, households with young children, hospitals concerned about the spread of foodborne disease, and school cafeterias and other restaurants that cannot accommodate a lunch or dinner crowd with reusables alone attest to the need for an alternative to permanentware. Add to this consideration the energy, water, and detergents used to wash permanentware and it seems clear that single service products have their place in modern life. Many organizations, such as Meals on Wheels, rely on the convenience, insulation properties, and high level of sanitation afforded by polystyrene food packaging in providing healthy food to their clients.

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2. Paper or Plastic?

Woman with foam coffee cup

One of the most obvious advantages polystyrene foam cups have over plastic-coated paper cups is that foam insulates better than paper. Paper cup users frequently use two cups together for hot beverages to protect their hands, or wrap layers and layers of paper napkins around the cup. This practice of "double cupping" an average-weight polyethylene (PE) plastic-coated paperboard cup results in over twice as much energy use and solid waste by volume, over five times as much solid waste by weight, and nearly twice as much greenhouse gas emissions as the use of a single average-weight polystyrene cup. (Franklin Associates, Ltd., Final Peer-Reviewed Report: Life Cycle Inventory of Polystyrene Foam, Bleached Paperboard, and Corrugated Paper Foodservice Products (Prepared for the Polystyrene Packaging Council, March 2006), pp. 2-7, 2-23, 2-43, 2-60) And since foam cups do their job using less material by weight, this can make a significant difference in the cost of resources needed to transport the packaging.

Life cycle analyses suggest that foam holds many other advantages over paper single service products. For example, Professor Martin Hocking, an associate professor of chemistry at the University of Victoria, British Columbia, has performed a study of foam and paper disposables. The results of his study were summarized succinctly in a Wall Street Journal article in 1991: "[Hocking's] analysis...finds that the environmental impact from the chemicals and energy used in making paper cups, as well as the emissions from incinerating or burying paper cups, exceeds the impact of making and disposing of cups made of plastic foam." (Naj, Amal Kumar. "Foam Cups Damage Environment Less Than Paper Cups, Study Says." The Wall Street Journal. 1 February 1991. See also: Hocking, Martin B. "Is Paper Better Than Plastic?" Consumers' Research October 1991: 28-29; Hocking, Martin B. "Reusable and Disposable Cups: An Energy-Based Evaluation." 18 Environmental Management 6. 1994: 894; Franklin Associates, Ltd., Resource and Environmental Profile Analysis of Foam Polystyrene and Bleached Paperboard Containers. June 1990: 4-1–4-29; Budiansky, Stephen. "Being Green Isn't Always What It Seems." U.S. News and World Report. 26 August 1996: 42.)

When you compare the manufacturing processes of hot beverage cups, a comparable-weight polyethylene (PE) plastic-coated paperboard cup with a corrugated sleeve requires more than twice the energy to produce as an average-weight polystyrene foam cup. (Franklin Associates, Ltd. , Final Peer-Reviewed Report: Life Cycle Inventory of Polystyrene Foam, Bleached Paperboard, and Corrugated Paper Foodservice Products (Prepared for the Polystyrene Packaging Council, March 2006), Table 2-2, p. 2-7.) In addition, when you compare the manufacturing processes of cold beverage cups, a representative-weight wax-coated paperboard cup requires approximately 66% more energy to produce as an average-weight polystyrene cup. (Ibid, Table 2-3, p. 2-8.)

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3. How are foam foodservice products made?

All manufacturing processes have environmental consequences, just as all living creatures contribute, however minimally, to environmental degradation. The real answer on environmental impact comes from a comparative analysis with suitable alternative manufacturing processes.


Polystyrene is made from styrene, a petroleum by-product, through a chemical reaction process known as polymerization. In addition to use in food packaging, polymers made from styrene are also extensively used today in the manufacture of automobile parts, electronic components, personal computer housings, boats, recreational vehicles, and synthetic rubber products. More information on styrene is available at the Styrene Information and Research Center (SIRC) website, at


Dart Container employs two distinct types of processing to make its products: 1) steam chest molding of expandable polystyrene (EPS); or 2) extrusion of polymer followed by thermoforming to achieve a final product.

Steam Chest Molding

Dart foam cups are made from expandable polystyrene (EPS). The first step in making EPS is impregnating small beads of polystyrene with an expansion agent, usually pentane. The molding process begins with limited expansion of the EPS by contact with steam in a pre-expander. The resulting “prepuff” forms the final product in a mold, also heated by steam that further expands and fuses the prepuff to its final shape and density.


The three classes of product in this second category are Impact, Oriented Polystyrene (OPS), and Extruded Foam.

Impact - Dinnerware, cold cups, portion containers, and lids are produced from extruded sheets of impact-modified polystyrene, polyethylene terephthalate, or polypropylene that are formed into final products in a thermoforming process utilizing heat and vacuum.

OPS – General Purpose (GP) polystyrene is extruded into a sheet that passes through an orienting device which stretches or “orients” the sheet to achieve strength. This oriented sheet is then thermoformed into a final product. The strength and clarity of OPS products is useful for packaging such items as baked goods, salads, and “deli” products. Our customers value the superior clarity of Dart's OPS products.

Extruded Foam – Dart also produces foam in a direct injection foam (DIF) process that involves an expansion or blowing agent added to the polymer during extrusion. The resulting foam provides both strength and insulation properties. Most of this product line has the typical pure white of expanded foam, but limited colors are available. Products made from this material include dinnerware and hinged trays.

Blowing Agents

Polystyrene foam foodservice products are not manufactured with chlorofluorocarbons (CFCs) or any other ozone-depleting chemicals. In fact, Dart has never used CFCs in manufacturing molded foam cups. Those manufacturers of polystyrene foodservice products that employed CFCs in their manufacturing operations ceased using them by 1990 (Judd H. Alexander, In Defense of Garbage [Westport, CT: Praeger Publishers, 1993] 55).

The most common blowing agents today are volatile organic compounds (VOCs) such as pentane. Unlike CFCs, pentane does not affect the upper ozone layer, but does contribute to impurities in the lower level of the atmosphere. State and federal authorities, through laws and regulations, limit the amount of VOC emissions allowed, depending on regional air quality issues. To meet the permitted limits of these regulations, many manufacturers use state-of-the-art technology to reduce pentane emissions (see for example: The Polystyrene Packaging Council, Polystyrene and Its Raw Material Styrene: Manufacture and Use November 1993; Updated January 1996). Whenever possible, Dart uses such technology to capture and destroy VOCs, and, where technically feasible, to capture and reuse pentane.

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4. What about disposal and landfill issues?

Compared with many other materials, polystyrene comprises a small percentage of both the total municipal solid waste (MSW) generated and disposed. In fact, all polystyrene plastic products represent approximately one percent of all products generated, by weight, in municipal solid waste. Of this total, polystyrene foodservice packaging accounts for approximately 0.4 percent, by weight, of all polystyrene products generated. This category includes items such as cups, plates, bowls, trays, clamshells, meat trays, egg cartons, yogurt and cottage cheese containers, and cutlery. Also, polystyrene foodservice products comprise less than one percent (0.7%) of MSW disposed. (United States Environmental Protection Agency, Municipal Solid Waste in the United States 2010 Facts and Figures, November 2011, Table 3)

In addition, compared to an average-weight polystyrene hot beverage cup, an average-weight polyethylene (PE) plastic-coated paperboard hot beverage cup produces almost three times as much total waste by weight, (Franklin Associates, Ltd., Final Peer-Reviewed Report: Life Cycle Inventory of Polystyrene Foam, Bleached Paperboard, and Corrugated Paper Foodservice Products (Prepared for the Polystyrene Packaging Council, March 2006), Table 2-10, p. 2-23) and an average-weight polyethylene (PE) plastic-coated paperboard cold beverage cup produces almost two and one-half times as much total waste by weight, as an average-weight polystyrene cold beverage cup. (Ibid., Table 2-11, p. 2-24)

Although greater amounts of municipal solid waste (MSW) have been recycled and composted in the last forty years, the majority of MSW generated in the United States is still safely disposed of in landfills.

Contrary to popular public belief, waste materials do not readily biodegrade in modern landfills. Today's modern MSW landfills are not like compost piles, where the purpose is to bury trash in such a way that it will decompose quickly. Today's modern MSW landfills are designed to discourage biodegradation by isolating the waste from oxygen, sunlight, and water - all of which are required for biodegradation to occur.

Modern landfills are well-engineered facilities that are regulated under strict federal and state regulations to ensure protection of human health and the environment. Because biodegradation can lead to the release of harmful methane gas or leachate, which can contaminate groundwater, it is actually preferable to place non-biodegradable rather than biodegradable products in landfills.

Newspapers & other wastes after 10 years in landfill
Newspapers and other wastes after 10 years in a sanitary landfill.
Study by Riley N. Kinman, PhD., Dept. of Civil & Environmental Engineering Hazardous Waste Management Program.

To learn more factual information about landfills, please visit the following websites:
United States Environmental Protection Agency — Landfills
How Stuff Works — How Landfills Work
Plastics Canada — Retention in Landfills

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5. What about litter?

We've all seen and heard the slogans. And we all know that litter is just plain bad. What many people, however, are unwilling to admit, is that litter is a "people issue" not a product issue.

Litter is misplaced waste, often blown by the wind, floating through storm drains or accumulating along curbs or fences. It is estimated that in some areas half the litter accumulation consists of cigarette butts. Studies also indicate that most littering occurs within 5 meters (16.5 feet) of a garbage can. 80% of marine debris originates on land! The remaining 20% consists of lost cargo and refuse from freightliners, cruise ships and fishing vessels.

The who, what, why of litter: Many studies have been conducted to determine who litters, why they litter, where they litter and what items become litter. Everyone recognizes that litter is offensive, unsanitary, and can carry disease. These studies found that people generally litter because it is easy to do so, they feel no ownership of the property, and often believe that someone is being paid to clean up after them. Litter flies from passenger vehicles and uncovered trucks and falls from pedestrians' hands. Often, people don't even consider the item – such as food scraps and cigarette butts – to be litter. There is no conclusive evidence that those who litter fit into any demographic category.

The many web sites, studies, and organizations dedicated to studying and solving litter problems make no mention of blaming products. Condemning a product and removing it from use simply because of its potential to become litter is an unrealistic approach to the problem. Under those circumstances the following items found during litter clean-up days would no longer be available to consumers: appliances, bottles, car parts, fishing line, shoes, mattresses, syringes and other medical waste, furniture, and toys.

The only true solution to litter is to change the behavior of those who litter and enforce the laws that prohibit this behavior. According to Keep America Beautiful (KAB), "Laws and ordinances that improve a community's quality of life are ineffective unless they're enforced. Enforcement is not only the role of the police department. It is most effective when police work in partnership with the community and its citizens, local public agencies and the courts." Set a good example and don't litter. The Canadian Plastics Industry Association (CPIA) has many resources available for the anti-litter efforts in your community. Keep America Beautiful, at its website,, offers a program to aid communities in assessing litter problems, addressing the issue, and measuring results.


Keep America Beautiful

Dart Container Corporation and others in plastics manufacturing are signatories to a voluntary "best practices" industry program, Operation Clean Sweep (OCS). Plastic resin pellets, if not properly managed and contained on land, can be swept into our waterways via stormwater drains, and make their way out into rivers, lakes, and oceans. They become another form of pollution and in large quantity can also be deadly to marine life. OCS practices have as their goal Zero Pellet Loss and the program is designed to help plastic manufacturers, processors, and transporters implement the practices that will get them to zero.

To learn more about OCS, visit:
Operation Clean Sweep

Marine Debris

Please visit to learn more on the issue of marine debris, what the plastics industry is doing to minimize the generation of litter in the waterways, and what all of us can do as well. This site is dedicated to providing the latest and most substantive information available on the causes and sources of marine debris, and most importantly, to finding solutions.

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6. Are foam products biodegradable?

Man & Woman with lunch - foam products

In theory, biodegradation sounds wonderful. Many people purchase paper foodservice packaging because they believe it will biodegrade quickly. We all like to think that litter and solid waste problems could be solved by allowing materials to biodegrade, but seldom are answers to complex questions so simple or easy. In fact, engineers design modern landfills to discourage biodegradation by removing oxygen, sunlight, and water.

Ironically, one beneficial feature of polystyrene foam is that it does not biodegrade significantly. According to Dr. William L. Rathje, an archaeologist with the University of Arizona's Garbage Project and a leading solid waste authority, "[t]he fact that plastic does not biodegrade, which is often cited as one of its great defects, may actually be one of its greatest virtues." Because biodegradation can lead to the release of harmful methane gas or leachate, which can contaminate groundwater, it is preferable to place non-biodegradable rather than biodegradable products in landfills, although obviously landfilling is a last resort for disposal. For more information, see: Rathje, William L., "Rubbish!" The Atlantic Monthly December 1989: 103. See also: Rathje, William L., and Cullen Murphy, "Five Major Myths About Garbage, and Why They're Wrong," Smithsonian July 1992: 5.

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7. Can foam products be recycled?

Yes. Foam # 6 is a thermoplastic, which means that it can be completely recycled.

From a technical standpoint, converting foam into recycled pellets is very easy. And by using widely available compactors specifically designed for foam (densifiers), it is economically feasible to load 40,000 pounds of foam on a 48’ trailer to transport the material to a recycling facility.

Because technological advancements with densifiers make foam recycling more viable, some cities have started adding foam to their curbside and drop-off collection programs. More information about recycling locations in North America can be found below within question 8.

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8. Where can I recycle my foam cups and containers?

In the United States, Dart customers can participate in Dart's CARE program or Recycla-Pak program to take advantage of foam recycling.

The first program, CARE (Cups Are REcyclable), provides larger users of foam products with an integrated, efficient method of recycling. The customer pays a monthly service fee and is then provided with a densifier to compact post-consumer foam foodservice products (e.g., cups, plates, bowls, clam shell containers) into a cylinder for convenient storage and transportation. The cylinder is then backhauled on a Dart truck for reprocessing at a Dart recycling facility. More Details.

The second program, Recycla-Pak, is a mail-back program designed for beverage service on a smaller scale. The program enables businesses to purchase a container that serves as a collection device and shipping container. Pre-paid shipping is included in the purchase price. The cups are then recycled in a Dart or industry facility. More Details.

More communities are now accepting clean foam foodservice containers in their curbside recycling programs than ever before. For a list of cities that recycle, go to

In Canada, foam cups and containers can be and are currently being recycled. In fact, in Ontario, approximately 90 municipalities, representing over 50 percent of all households in the province, have access to blue box recycling programs (both curbside and depot collection) that collect post-consumer foam cups and containers. Also, the City of Toronto added foam cups and food containers to the City's Blue Box program in December 2008.

In addition, Dart currently operates foam #6 drop-off locations at fifteen North American production plants for anyone who wishes to recycle foam products. Our equipment is capable of reprocessing 12 million pounds of foam products annually. More Details.

To see if there is a location that recycles foam #6 near you, go to and search "#6 Plastic (Polystyrene)" and "Styrofoam."

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