Some grocery stores have begun to switch to what has been called "environmentally friendly" compostable plastic bags.
It would be nice if these bags were the simple solution to our bag problems and we could keep using plastic without noticing a change or skipping a beat.
But unfortunately compostable plastic bags are not the green solution they appear to be and instead end up confusing the customer into believing they are making a good choice for the environment when they are not.
So even if the store also sells other truly sustainable reusable bags to be used for produce or bulk food items the customer doesn't see the need to invest in these more expensive bags.
Compostable Bags are usually made from either corn or potatoes.
It turns out though that starch polyester bags have a higher global warming potential than conventional polymer bags – meaning they emit more CO2 to produce than conventional plastic bags.
It requires a lot of land to grow corn for plastic instead of for food.
The corn used to make the corn resin, known as polylactic acid (PLA), used for compostable plastic bags is largely GMO corn.
We have to mention a related topic which is the already massively over subsidized mono-culture of conventionally fertilized, sprayed, GMO-ed CORN. This is about BIG AGRICULTURE dominating the marketplace vs. supporting organic farmers that grow a variety of vegetables, grains, and nuts!
The effect on the public is corporate control over our food growing and eating options, having less choice and support for local farmers, ingesting corn syrup in almost every processed food we eat which contributes to our obesity rates and using a large percentage of that corn to feed millions of factory farm animals that can’t digest it, get sick and need antibiotics from it and should be eating grass instead.
Landfilling compostable bags has larger eco-impacts than landfilling plastic bags.
You cannot recycle compostable bags. And, if you get mixed up and try to compost a regular plastic bag, you get contaminated compost. When these bags get composted, they don’t produce anything like compost, but rather just carbon and water.
What about “oxo-degradable” bags?
Oxo-degradables are plastic with metal salt additives that help the material disintegrate rapidly into tiny particles. You won’t be able to see it anymore, but it is still there, in the ocean too. Just as with conventional plastics, these oxo-degradables release harmful substances when they are broken down. Once again these bags are just another Green Washing attempt to that is not sustainable.
So, the word is out – compostable bags are NOT the answer – even though we really wish they were the natural alternative they seem like they should be.
For more in depth reading on all things textiles go to oecotextiles.wordpress.com
For a great article on biodegradable plastic see Corn Plastic to the Rescue