And then when cooled again to room temperature, it becomes solid. This is what makes it useful for commercial products. In manufacturing, polystyrene usually starts as small beads. These dense, hard beads are softened by heat and expanded using things like steam and blowing agents, becoming much larger and less dense beads.
During expansion, the beads become skinned cells that may be as little as 3 percent as heavy as the original bead, with most of the volume being gas. These expanded cells may then be formed and bonded into useful shapes.
In finished form, EPS has a number of useful properties. It insulates; that is, it slows heat transmission. It absorbs shock. It is not dissolved by common liquids like water, serving as a barrier. So it may be great for boiling hot coffee, picnic coolers, bicycle helmets, home insulation, packing materials, restaurant carry-out containers and egg cartons.
This is not to say that styrofoam is the only, or the best, material for these applications. We love a radio-video piece by Jacob Fenston and Tyrone Turner of WAMU, who showed that styrofoam egg cartons are not necessarily better at protecting eggs. Why, then, is styrofoam of environmental concern?
Simply put, it gets into the ocean and other environmental realms, and it does not go away for a very, very long time. Worse yet, it disassembles into its component little cells, which float away and can be consumed by aquatic and marine creatures. A lot of styrofoam waste does go into landfills better than the ocean, but hardly great. But styrofoam is notoriously hard to recycle, and is not accepted by most municipal recycling programs.
Styrofoam is not exactly a, um, health food either. If your kid swallowed a piece of it, it probably would not hurt them, as long as it passed through. But the styrene monomer from which it is made is suspected of causing cancer and other health problems , and miniscule amounts of styrene could leach into your hot coffee.
For the occasional coffee, it may not be a big concern. But certain conditions cause polystyrene to break down chemically and possibly leach styrene. Heat and hot liquids may be a problem. And microwaving your styrofoam may be iffy.
There are also a number of solvents e. A U. Environmental Protection Agency study found styrene residues, however infinitesimal, in percent of the human fat tissue samples taken.
Styrene toxicity may be much greater for people exposed occupationally or via air pollution. Cells from broken-down styrofoam find their way into streams, lakes and oceans. Styrofoam is commonly used in disposable products that are only used once. These products can persist in the environment for more than a million years, however, since polystyrene is not biodegradable. Though it is slow to break down chemically, Styrofoam does however fragment into small pieces, choking animals that ingest it, clogging their digestive systems.
Styrofoam and other plastics currently make up about 30 percent of the landfill volume in the United States. Some restaurants and food vendors have substituted cardboard and paper products for Styrofoam in cups, fast-food "clamshells" and other food packaging. Especially in the presence of moisture, paper fibers break down within weeks to months.
Biodegradable alternatives such as "soapstock waste" from agricultural operations can replace Styrofoam for protecting packages, and recycled paper can be used for cups, eliminating some Styrofoam waste. Max Roman Dilthey is a science, health and culture writer currently pursuing a master's of sustainability science.
Based in Massachusetts, he blogs about cycling at MaxTheCyclist. Physical Properties of Styrofoam. Earth Friendly Food Storage Containers. Since then, similar bans have been put in place around the country—on Styrofoam, plastic bags and, most recently, plastic straws—resulting in years of litigations and millions of dollars worth of legal fees.
Styrofoam is still here—but is that good or bad? Between and , the rate of polystyrene production increased expotentially. In the Dow Chemical Company trademarked Styrofoam. In the process of trying to make polystyrene more flexible, Dow scientist Ray McIntire mixed together styrene and isobutene in a reactor and heated them.
The result was extruded polystyrene foam, a strong material that is moisture resistant and composed of 98 percent air—so incredibly lightweight and buoyant that it was considered a wonder product.
Its low cost and ease of production catapulted Styrofoam into our lives. From energy efficient building insulation to surfboards, and from soilless hydroponic gardening to airplane construction , Styrofoam was heralded as the wave of the future—until the environmental issues came up.
In the s, research found that EPS foam not only degrades in seawater, but also that the resulting pieces called styrene monomers are toxic when ingested by marine life.
There are several concerns here, he adds. One is that creatures that fill up their stomachs with plastic pieces may not be able to get enough food. Two is that that chemicals, particularly endocrine disruptors, might leach out of that plastic and harm the wildlife—or worse, make their way into the human food chain.
And yet, for all its bad press, Styrofoam actually has its advantages over other packaging products, says Trevor Zink, an assistant professor of management at the Institute of Business Ethics and Sustainability at Loyola Marymount University. Agilyx uses their pyrolysis-based technology to convert various plastic waste into hydrocarbon products—basically it breaks polymers down into elemental constituents, which can work very well for Styrofoam recycling.
After compacting it and mixing the Styrofoam with other types of polystyrene foam plastics, Agilyx converts it back into a type of oil that can be used in manufacturing of anything from bicycle helmets to high quality synthetic crude oil. The crude oil is a particularly promising application since it swaps a non-renewable resource with a renewable one.
Agilyx has sold their crude oil to a refinery that has turned it into jet fuel that was then sold to the department of defense. Another company, Styro-Gro , has outfitted trucks with built-in Styrofoam compactors for convenient pick-up and then converts it into faux marble or quartz.
Turns out, it all boils down to economics—volume, weight, and a functioning recycling process. Foam is a problem child for many facilities since it can easily break up and contaminate other, more profitable recyclables. Anna Dengler, Vice President of Operations for corporate sustainability consulting firm Great Forest , says that when advising clients on whether or not to recycle Styrofoam, it comes down to volume and weight.
For a large-scale urban business this is a possibility, but many smaller companies are limited by availability of haulers. With these findings, the city was able to successfully implement a ban on expanded Styrofoam containers and packing peanuts, which will go into effect in Murphy salutes it—his work at Environment Michigan includes efforts to implement a statewide Styrofoam ban.
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