Bioplastics
A Target giftcard looks and feels like regular plastic, but it's made of a new plant-based material called Mirel PHA that biodegrades in a compost bin. It's also the only bioplastic currently with the ability to decompose in soil or streams.
The Target giftcard takes 40 days to break down into carbon dioxide and water. If buried in a landfill where there's moisture but not air, it breaks down anaerobically and gives off methane, a greenhouse gas.
Critics complain that this innovative plastic takes too long to biodegrade and that it's biodegrading trait produces green house gasses such as carbon dioxide and methane.
But rotting plastics isn't the only source of methane. Kitchen scraps and yard waste also give off the greenhouse gas, which is why dumps sites that take regular garbage or garden waste have started to "harvest" methane by capturing the gas and burning it for energy.
Other biodegradable items include Paper Mate pens, mechanical pencils, and SunChips bag. However, in order for these items to biodegrade, they must be placed in a compost heap. Problem is, some people refuse to recycle, and these people are even less likely to start a compost heap. Those who don't mind composting themselves or taking their plastics to an industiral composting site complain about the noise the bags make. It's unfortunate that eco-friendliness still takes a backseat to convenience.
Then, there is the problem of higher costs.
There are 2 new variesties of bioplastics: polylactic acid, or PLA, is clear. It costs manufacturers 20% more compared to petroleum-based plastics. The other is polyhydroxyalkanoate, or PHA. This biodegrades faster but is more than double the price of regular plastic.
Both plastics are made of fermented corn sugar. Other manufacturers are trying to mke PLA from switchgrass, potatoes, and algae.
Manufacturing bioplastics is greener than manufacturing non-biodegradable plastics because it produces fewer greenhouse-gas emissions compared to the petrochemical-based plastics.
Continued on the next page
Follow Technorati