Polystyrene foam, widely recognized by the brand name Styrofoam, is a lightweight material used extensively in packaging, food service, and construction insulation. Valued for its protective and thermal properties, its structure presents a significant environmental dilemma at the end of its useful life. The question of whether to burn or throw away this material highlights a conflict between acute health hazards and long-term environmental persistence. The proper disposal of expanded polystyrene (EPS) is a major challenge in waste management systems globally.
Toxic Emissions from Burning Polystyrene
Incinerating polystyrene foam, especially in uncontrolled settings like a backyard fire, releases a complex mixture of harmful chemicals into the air. This process often occurs at lower temperatures than industrial incinerators, resulting in incomplete combustion that maximizes the release of toxic byproducts. Burning polystyrene releases styrene monomer, the plastic’s chemical building block, which is classified as a possible human carcinogen and a neurotoxin. Exposure to styrene can cause symptoms like headaches, fatigue, and dizziness, and chronic exposure may affect the central nervous system.
Combustion also yields polycyclic aromatic hydrocarbons (PAHs), compounds known to be carcinogenic and linked to birth defects. The lack of oxygen in an open burn scenario leads to the production of carbon monoxide, a colorless, odorless gas deadly in high concentrations. Hydrogen cyanide, another highly toxic compound, can also be released, which is more potent than carbon monoxide and can rapidly impair cognitive function.
Uncontrolled burning of polystyrene is illegal in many jurisdictions due to the severe air quality and health hazards it creates. Even when burned in specialized industrial incinerators operating at extremely high temperatures (around 800–900 °C), the emissions can still contain a complex array of over 90 different compounds. Any form of open burning poses a direct threat to human health and the surrounding environment.
The Problem of Landfill Volume and Persistence
Throwing away polystyrene foam into a landfill avoids the immediate toxic emissions associated with burning but introduces severe long-term environmental issues. Polystyrene is non-biodegradable; once placed in a landfill, it will persist for hundreds, possibly thousands, of years without breaking down naturally. Every piece of polystyrene ever produced largely still exists.
Expanded polystyrene (EPS) is about 95% air, making it extremely lightweight but incredibly bulky. This structure causes it to take up a disproportionately large amount of space in landfills relative to its mass. Estimates suggest it can account for 25% to 30% of total landfill volume in the United States. This sheer volume places a significant strain on waste management infrastructure and reduces the lifespan of landfill sites.
If the material escapes the landfill, its lightweight nature allows it to be easily carried by wind or water currents, becoming a pervasive form of environmental litter. Over time, this plastic fragments into microplastics, which can contaminate soil and waterways. These fragments are often mistaken for food by wildlife, leading to intestinal blockages and starvation in birds and marine animals.
Preferred Disposal Methods and Polystyrene Recycling
Since both burning and standard landfilling are environmentally harmful, the preferred methods for managing polystyrene involve recycling or reuse. Polystyrene is technically recyclable, designated by the plastic resin code #6, but it requires specialized processing not available in most curbside programs. The primary obstacle to recycling is the material’s low density, which makes it uneconomical to transport long distances to a processing facility.
Effective polystyrene recycling relies on densification, a process that uses specialized equipment to compress the material into compact blocks. This compaction can reduce the material’s volume by up to 95%, making it cost-effective to ship to reprocessors. The densified plastic is then melted and extruded into pellets for use in new products, such as insulation, picture frames, and construction materials.
For home users, the best options involve locating specialized drop-off centers or participating in mail-back programs offered by some manufacturers. Contamination is a major challenge; the material must be clean and free of food residue to be accepted for mechanical recycling. Chemical recycling methods, such as depolymerization, are also being developed to break the plastic into its original monomer components, which can then be used to create new, high-quality polystyrene.
Determining the Better Disposal Choice
Based on the evidence, throwing away polystyrene for landfill disposal, though imperfect, is less detrimental than burning it. Landfilling creates a long-term volume and persistence issue, but it does not produce the immediate, acutely toxic air pollutants that burning does. The harmful emissions released during uncontrolled combustion, including styrene monomer and carbon monoxide, pose a direct and severe risk to human health and local air quality. Specialized recycling or reuse is the optimal solution. However, if a choice must be made between the two least desirable options, disposal in a regulated landfill is the safer action.