WASHINGTON — The American Plastics Council has released two studies touting the benefits of plastics for fighting global warming. APC plans to do three more studies to bolster the argument that some plastics have an overall positive effect in reducing greenhouse gas emissions. The studies, released Feb. 29 at a Washington news conference, argue that polyurethane refrigerator insulation and high density polyethylene or polypropylene house wraps lower utility bills, saving much more energy than it takes to manufacture them.
Arlington, Va.-based APC does not plan to get involved in the politics of the global warming debate, leaving that to the Chemical Manufacturers Association, according to APC spokeswoman Susan Moore. But APC would like to steer the debate to focus on the life cycle of plastics, not just the energy spent to manufacture products.
"Together, these studies are useful in understanding the environmental balance sheet of plastics," said Steve Hentges, director of APC's polycarbonate business unit, who is overseeing the studies for APC.
"There is an old saying that you have to spend money to make money," he said. "These studies offer a slightly different take: You have to use energy to save energy."
The refrigeration study said PU insulation can save enough energy after six weeks of use to make up for the energy spent to manufacture it.
Replacing older appliances with newer models that feature PU insulation will cut carbon dioxide emissions by 41.5 million tons a year. The study compared refrigerators with PU insulation to those that use fiberglass.
The report had one caveat: It compared refrigerators of the same dimension, but assumed they would have equal amounts of insulation. In the real world, however, appliance makers typically use more fiberglass than they would PU in similar-size refrigerators, which gives the PU models more storage space.
According to the other study, plastic house wrap can reduce the amount of outside air that filters into a home by 10-50 percent. Since air infiltration accounts for about half of all energy used in heating or cooling a home, the study estimates that plastic house wrap has cut greenhouse gas emissions by an estimated 120 million tons to 600 million tons since 1980.
The three additional studies will look at home insulation, automobiles and food packaging.
Hentges said the insulation study will be finished in a few weeks, but will not compare the different types of plastic insulation. Rather it will create an average for all plastic insulation, weighted by market share.
The auto and food-packaging studies are more complicated, and Hentges could not say when they will be available.
The auto study will look at greenhouse gas emissions reduced by lighter cars, and the packaging study will examine the energy saved by not having to replace damaged food.