GOODBYE STYROFOAM, HELLO BIOFOAM
The world's largest manufacturer of foam cups recycles them here in Michigan but researchers at Michigan State University are looking to replace plastic foam with biofoam. <This story was republished in EJ Magazine>
Styrofoam has a bad reputation. In fact, most of what is thought of as Styrofoam is actually foamed polystyrene or polyethylene. It’s not evil, but most would agree that the processes used to make it aren’t exactly great for the environment.
Styrofoam got its bad name in the early 1980’s. Back then, the foams were made by aerating plastic with chlorofluorocarbons or CFCs, which were linked to the growing hole in the ozone layer. As a result, plastic foam cups and food containers were banned in several West coast cities; major food chains like McDonalds stopped packing their burgers into foam clamshells; and the foam manufactures found other blowing agents. Almost everyone stopped using them in 1987 when the Montreal Protocol, an international agreement aimed at phasing out CFCs, went into effect.
But Styrofoam’s ill repute doesn’t stop with CFCs. Foamed plastic is now just like any other plastic: it’s made from petroleum and takes eons to degrade. About 20 percent of municipal waste is made up of plastic, most of which is packaging, according to the Environmental Protection Agency. The big difference is foam is mostly air.
But the plastics industry and researchers at Michigan State University are trying to change that by making foam the most environmentally friendly packaging around. Some try to recycle it.
Shipping businesses often take packing peanuts back and heavy-duty formed foam can be cut up and reused once or twice for shipping but food-contaminated foam, like the trays that come with raw meat from the grocery store, rarely gets another chance. There are only a few places in the United States where foam food containers are recycled.
Dart Container Corporation is the largest manufacturer of foam cups in the world. As a side-business, Dart has been recycling foam for 15 years at their headquarters in Mason, Mich., mostly into a low-grade form used to make plant trays. Dart does internal recycling as well.
When the recycling plant is out of commission for repairs, like it was in January 2007, the foam quickly piles up.
Outside the metal-sided factory, there are small sheds where anyone can drive up and drop off their cups or peanuts.
Half of the 2000-square-foot room at the front of the facility is packed to the ceiling with bags of cups, plates, lunch trays and packaging, dropped off by nearby residents or trucked in from schools. Even on an “off” day, the noise of the running machinery is deafening.
Further inside, a huge pile of ripe-smelling foam lunch trays and cups waits for the plant’s workers to resume their 24-hour-a-day hand sorting.
The chemists at the plant have tried to isolate the food smell, which persists even after washing, but the contamination is so minute it can’t be detected with the lab’s equipment.
After sorting, the foam is placed on the “godillza-vator”––a giant conveyer that heads at a 70-degree angle toward the ceiling. From there the foam is sliced and diced, washed and dried, and then heated and formed into tiny pea-sized grains for resale.
Despite the benefits of keeping foam out of the landfill, recycling has its challenges. For one the foam needs to be dried, which takes energy. Fred Forrestor, Dart’s chief engineer explained, “What you have are millions and million of little sponges and you have to get rid of that water.”
Transporting foam also takes a lot of energy and space, but doesn’t yield much material, often a losing proposition. It’s like trucking around air. Dart feels a responsibility to take back the food-contaminated foam, Forrestor said, but not many companies are following suit.
Ramani Narayan, a Michigan State chemical and bioengineering professor, can understand why most companies don’t recycle foam.
“The key is not whether something is recyclable, but does it actually get recycled? Is the infrastructure there? And, more importantly, is it cost effective?” Narayan asked.
Narayan has a plan for foams that eliminates the need for recycling. He has worked with plastic industry companies like Cargill Inc. on polylactic acid (PLA) or corn plastic, a starch-based plastic currently used in plastic cups and flatware. He has also researched and patented new bio-based foams. These foams are made from plant starch and water, renewable resources.
Renewable sources like plants are ideal when it comes to disposable items because they make the final product carbon neutral, Narayan said. In a biodegradable cup, the starch from plants that take carbon out of the air is harvested and processed, after the cup is used it biodegrades, releasing the carbon back into the atmosphere.
These bio-based foams, sold as Green Cell Foam, have appeared as packaging for Toyota parts and ice cream shipping containers. These foams dissolve in water, which is convenient for shippers but not for the coffee lover. But the solution isn’t carrying mugs from coffee shop to coffee shop. Overcoming these problems is the job of engineers, Narayan said.
“Disposable plastic-ware, like forks, knives, spoons, plates, are not necessarily bad,” Narayan said. “You don’t want the person making stuff in the fast food restaurant to use their hands. You want them to use disposable gloves.”
Though biodegradable foams make sense, they won’t become widespread until costs come down and the foams become less temperature and water sensitive. Also, while biofoams are biodegradable, what happens to them after use is still important to consider.
Modern landfills are lined with cement and are a dead end for biodegradables like grass clippings, discarded food and biofoams. The EPA estimates that each household sends 700 pounds of compostable waste to the landfill every year, over 44 million tons. They need to be composted in order to become “food for the soil,” according to Narayan.
Mama Bear’s café in Lansing, Mich. serves its organic, local fare on reusable plates but owner Cecilia Garcia said they use compostable cups, bowls and flatware for to-go orders.
“We encourage our customers to compost at home. If someone’s not a regular we’ll tell them to put it in their compost and it’ll degrade in 45 days,” she added. The restaurant also recently got permission from the city to compost food waste on site.
Dart’s Forrestor suggested plastic foams could be a source of fuel in the future. Provided they are combusted in a well-controlled incinerator “these polymers retain the same kind of energy level that they had when they came out of the ground as petroleum,” he said. Similarly, biofoams can be burned for their energy.
These days, there are lots of “end of life” options for plastics.
“Disposables have helped us maintain our health and the only thing we have to make sure of is that after use it gets disposed of in the proper, whether it is waste to energy, recycling or biodegraded in composting conditions,” said Narayan.
If industry and researchers have their way, disposable plastics aren’t going away, unless they’re in a compost bin.
ON LOCATION
Dart Container Corp.
MSU Engineering Building
IN PERSON
Fred Forrestor, Dart’s chief engineer
Ramani Narayan Chemical and Biochem Engineering Prof.
Cecilia Garcia, Owner Mama Bear's Cafe
PLASTIC TERMS
Photodegradable. Some plastics degrade when exposed to light and air, but while they disappear from view, tiny molecules of the plastic still hang around indefinitely.
Biodegradable. Anything that can be broken down by microorganisms is considered biodegradable but some biodegradable plastics are a mix of petroleum and starch- only the starch degrades leaving bits of plastic behind.
Compostable. The America Society for Testing Materials (ASTM) has specifically defined compostable to mean the product will degrade within 180 days in large-scale composting conditions without leaving toxic materials behind.
Compost. A pile of organic material home to heat-loving bacteria that chew up the material into a soil amendment.
BPI Label. The Biodegradable Products Institute created this label to help consumers recognize products that meet the ASTM composting standard.
RELIABLE SOURCES
EPA on Composting Find out more about home composting and municipal services near you.
Biodegradable Products Institute
Look for certified biodegradable products with the BPI label.
