Styrene monomer, a crude oil product, is the base material from which polystyrene is produced. Through a process known as polymerization, molecules of styrene monomer are chemically linked to form the polymer polystyrene.

Styrene is a naturally occurring chemical. Traces of styrene monomer can be found in such healthy foods as strawberries, apples, peaches, beans, fish, milk and fruit juices. In fact, we ingest styrene naturally everyday of our lives in a variety of food products. When heated, polystyrene softens and can be readily converted into a wide range of finished articles.

Foamed polystyrene is created by adding a hydrocarbon blowing agent to the polymerisation process. Since hydrocarbons do not contain any chlorine molecules, they are ozone friendly; the manufacture of foamed polystyrene products thus does not contribute to the destruction of the ozone layer.

Foamed polystyrene offers a number of outstanding properties:

• It is light and impervious to moisture
• In food packaging, it provides a high level of protection against spoilage, keeping food fresh for longer
• It is clean, hygienic and reduces the need to handle foodstuffs.
• It is non-toxic and non-tainting
• Its rigidity and strength to weight ratio offer excellent cost performance all along the line
• It provides good insulation
• It can be easily processed in a range of colours

Clean, homogeneous foamed polystyrene waste-e.g. all process scrap from the production of finished articles- is readily recyclable. Used polystyrene packaging can be recovered from the waste stream, cleaned and recycled for re-introduction into the manufacturing process. It is used for a variety of end uses ranging from coat hangers to building insulation panels.

No. Manufacturing processes are the final product conforms to the most stringent international health and safety standards, and foamed polystyrene is approved for food contact. When used for protective packaging, foamed polystyrene keeps food fresh and free from bacterial contamination, because polystyrene does not support bacterial growth, disposable foamed polystyrene does not support bacterial growth, disposable foamed polystyrene plates and cups offer considerable hygiene benefits in food service.

For example, did you know the shampoo we use to make our hair feel so clean contains hydroxypropyl methylcellulose - and the "natural" barley and wheat cereal that makes us feel so healthy is made with thiamin mononitrate? With these wordy terms in mind, it is not hard to understand why people get confused when polystyrene manufacturers attempt to explain the nature of their products.

This fact sheet, published by the Plastics Food Service Packaging Group and its members, presents the facts about polystyrene. This information should help you gain a deeper understanding of why polystyrene is the best choice for food service packaging.

Styrene, a petroleum by-product, is the primary raw material from which polystyrene is made. Styrene, first commercially produced in the 1930s, played an important role during World War II in the production of synthetic rubber. After the war, much of the use of styrene shifted to the manufacture of commercial polystyrene products. Synthetic styrene is also used in the manufacture of products such as automobile parts, electronic components, boats, recreational vehicles, and synthetic rubbers. Today, you or a member of your family will probably use a product derived from styrene.

Modern man has known about styrene for centuries. A naturally occurring substance, styrene is present in many foods and beverages, including wheat, beef, strawberries, peanuts and coffee beans. Also found in the spice cinnamon, its chemical structure is similar to cinnamic aldehyde, the chemical component that elicits cinnamon's flavor. It is naturally present to flavor foods, and is used as a flavoring additive to such food as baked goods, frozen dairy products, soft candy, and gelatins and puddings, with permission from the U.S. Food and Drug Administration (FDA).^?

The Plastics Food Service Packaging Group works closely with the Styrene Information and Research Center (SIRC), whose mission is to collect, develop, analyze and communicate pertinent information on styrene. Since 1987, SIRC has undertaken a comprehensive research program to enhance understanding of styrene's potential to affect human health and the environment.

Polystyrene meets stringent health and safety standards for use in food contact packaging and is safe for consumers. Health organizations encourage the use of single-use food service products, including polystyrene, because they provide increased food safety.^?

All packaging (glass, aluminum, paper, and plastic - including polystyrene) contains substances that can "migrate," or transfer, to foods or beverages. The FDA regulates residual levels of these components in food packaging to ensure that packaging is safe to use.

Polystyrene foam products are 95 percent air and only five percent polystyrene. When polystyrene foam packaging is produced, a blowing agent is used in the process. Most polystyrene foam products never were made using chlorofluorocarbons (CFCs) as a blowing agent. The few polystyrene products that were made with CFCs comprised a very small portion of the nation's CFC use. According to the U.S. Environmental Protection Agency (EPA), only two to three percent of CFCs used in the United States in the 1980s went toward production of polystyrene packaging products. At the forefront of U.S. industry, polystyrene manufacturers exceeded government goals and timetables during the phase out period of CFCs in the late 1980s.^??

Polystyrene foam products are now manufactured primarily using two types of blowing agents: Pentane and Carbon Dioxide.

Pentane gas has no effect on the upper ozone layer, although, if not recovered, it can contribute to low-level smog formation. Therefore, manufacturers use state-of-the-art technology to capture pentane emissions.

With ever-evolving technology, some manufacturers use carbon dioxide (CO2 or other hydrocarbons in some cases) as an expansion agent for polystyrene foam.

CO2 is non-toxic, non-flammable, does not contribute to low-level smog, and has no stratospheric ozone depletion potential. In addition, the carbon dioxide used for this technology is recovered from existing commercial and natural sources. As a result, the use of this blowing agent technology does not increase the levels of CO2 in the atmosphere.

(1) See: FDA's Food Additive Regulation at 21 CFR 172.515

(2) "Disposables versus Reusables: A Study of Comparative Sanitary Quality," Dairy Food and Sanitation, Jan. 1985.

(3) "Statement of Support for The Foodservice Packaging Institute's Fully Halogenated Chlorofluorocarbon Voluntary Phaseout Program," Natural Resources Defense Council/Environmental Defense Fund/Friends of the Earth, April 1988.