Biodegradable Products May Hurt The Environment

When a consumer selects a biodegradable product, they may pay more but justify the extra expense in the interest of helping the environment. But what it that product not only doesn't help, but might actually hurt the environment?

If you believe that greenhouse gas is a threat to the environment, a North Carolina State University researcher says you should view many biodegradable products as a threat as well. The reason?

“Biodegradable materials, such as disposable cups and utensils, are broken down in landfills by microorganisms that then produce methane,” said Dr. Morton Barlaz, co-author of a paper describing the research and professor and head of NC State’s Department of Civil, Construction, and Environmental Engineering. “Methane can be a valuable energy source when captured, but is a potent greenhouse gas when released into the atmosphere.”

Currently, the U.S. Environmental Protection Agency (EPA) estimates that only about 35 percent of municipal solid waste goes to landfills that capture methane for energy use. EPA estimates that another 34 percent of landfills capture methane and burn it off on-site, while 31 percent allow the methane to escape.

“In other words,” Barlaz says, “biodegradable products are not necessarily more environmentally friendly when disposed in landfills.”

Decompose quickly

Federal rules may make the problem worse. Federal Trade Commission (FTC) guidelines require products labeled as “biodegradable” to decompose within “a reasonably short period of time” after disposal.

But rapid degradation may actually be environmentally harmful, because federal regulations do not require landfills that collect methane to install gas collection systems for at least two years after the waste is buried.

If materials break down and release methane quickly, much of that methane will likely be emitted before the collection technology is installed. This means less potential fuel for energy use, and more greenhouse gas emissions.

According to the researchers, the slower a waste product biodegrades, the more environmentally friendly it is. Most of its methane production will take place after the methane collection system is in place.

“If we want to maximize the environmental benefit of biodegradable products in landfills,” Barlaz said, “we need to both expand methane collection at landfills and design these products to degrade more slowly – in contrast to FTC guidance.”