Styrofoam, commonly known as expanded polystyrene (EPS) foam, is a familiar material used in various everyday items, from disposable coffee cups to protective packaging. This material, despite its widespread presence and utility, raises questions about its environmental impact. Understanding its composition, how it is produced, and what happens to it after use provides insight into its broader ecological footprint.
Material Composition and Production Footprint
Expanded polystyrene foam, or EPS, is primarily made from polystyrene, a petroleum-derived plastic. Polystyrene beads are the base material, which are then expanded significantly using a blowing agent, often pentane, when heated with steam. This process creates a lightweight, cellular plastic material that is approximately 98% air.
Manufacturing polystyrene is an energy-intensive process, which can lead to greenhouse gas emissions. While some sources suggest that the manufacturing process itself uses less resources and energy than some alternatives, the overall reliance on petroleum contributes to environmental concerns.
Environmental Persistence and Pollution Impact
Styrofoam is not biodegradable; it does not break down naturally. It is chemically stable and can persist for hundreds to potentially millions of years once discarded. This material commonly ends up in landfills, where it occupies significant space, with some estimates suggesting it can take up to 30% of landfill volume.
When exposed to sunlight, Styrofoam undergoes photodegradation, crumbling into smaller pieces. This fragmentation creates microplastics, which are tiny plastic particles that remain in the environment indefinitely. These microplastics pose a threat to wildlife, as animals can ingest them, mistaking them for food, leading to blockages in their digestive systems or other harm. Its lightweight nature also makes it prone to being carried by wind and water, contributing to litter in streets and waterways, particularly marine environments.
Recycling Realities and Hurdles
While technically recyclable, expanded polystyrene foam faces significant practical challenges. Its low density makes it bulky and uneconomical to transport to recycling facilities.
Contamination further complicates recycling efforts, especially for food service items that are often soiled with food residue, oils, or other substances. Such contamination makes the material unsuitable for processing alongside clean materials. Additionally, the lack of widespread municipal recycling infrastructure for Styrofoam means that very few centers are equipped to handle it, as the process requires specialized machinery and can be labor-intensive. The market demand for recycled Styrofoam is also relatively low, which means that the cost of recycling often exceeds the value of the reprocessed material, making it an unprofitable venture for many recycling companies.
Chemical Leaching and Health Concerns
Styrofoam has the potential to leach chemicals, specifically styrene monomers, into food and beverages. This leaching can occur, particularly when the material is heated or comes into contact with fatty or acidic foods. Studies have observed styrene contamination in food simulants from polystyrene cups, trays, and plates.
Some advocacy groups have raised concerns about the health implications of styrene exposure, linking it to potential health issues including its classification as a probable human carcinogen by some bodies. However, regulatory bodies like the U.S. Food and Drug Administration (FDA) permit the use of styrene-based materials in food contact applications, provided they meet strict safety guidelines. The European Food Safety Authority (EFSA) has also concluded that styrene does not pose a genotoxic risk when ingested, provided migration limits are not exceeded.
Eco-Friendly Alternatives
Eco-friendly alternatives exist for applications traditionally dominated by Styrofoam, offering more sustainable options. For packaging, materials like recycled paper and cardboard are versatile and easily recyclable, serving as effective cushioning and inserts. Molded pulp, often crafted from recycled paper or agricultural waste, provides a compostable and biodegradable alternative suitable for protective packaging.
In food service, options such as bagasse, a fibrous byproduct of sugarcane, are increasingly used for containers due to their renewability and ability to withstand various temperatures. Cornstarch-based bioplastics, like polylactic acid (PLA), offer a plant-based resin that can be used for compostable containers and liners. Other alternatives include bamboo, which is fast-growing and compostable, and reusable containers, which reduce the need for single-use items altogether.