Attempting to be an environmentally-aware citizen, I try to do the right thing with my rubbish: I reduce where I can, reuse when I can, and recycle what I can. Despite the efforts, there is always some rubbish left over to be thrown in the bin. But the other day at the store, I ran into a quandary: which type of rubbish bag is the most environmentally friendly one?
Since I use reusable bags for most of my shopping – bags that are either cloth or are made from recycled plastic shopping bags – I don’t receive many bags from the store into which I can place my rubbish. That means I end up going to the store and buying rubbish bags.
This weekend I went to Tesco-Lotus, the local branch of the huge British retailer that is similar to America’s Wal Mart or France’s Carrefour. There in the household goods section were two different types of Tesco branded rubbish bags:
- Tesco Greener Living 100% Recycled Garbage Bags – Made with 100% recycled recyclable plastic.
- Tesco Greener Living 100% Oxo-Biodegradable Garbage Bags – Made with 100% virgin materials but recyclable and biodegradable.
I didn’t know what to make of these choices. First off, I wasn’t sure what oxo-biodegradable was but it sounded tricky to me. To top it off, why would any green initiative tout its use of 100% virgin materials?
Not having all day to ponder this, I made my choice for the 100% recycled bags and headed home, where I fired up the computer and did some research. From what I have read, “oxo-biodegradable” is the so-called second generation of biodegradable plastic bags:
PLA, or corn-based bags were the first generation. These seem to have many problems including not being recyclable through the normal process, imparting an off taste to water or other food products carried in them, and decaying so fast in an oxygen-free environment that they give off large amounts of methane.
This second generation, “oxo-biodegradable”, is made with a small amount of metal that allows it to biodegrade in a period of months or years – but only when exposed to oxygen. If it gets buried in a landfill, it won’t biodegrade any faster than a regular plastic bag. Plus, the metals added to the bag could cause problems with toxic contamination.
A third generation of biodegradable plastic bags are made from naphtha, one of the side products of the oil refining process. These bags are ostensibly more durable than the oxo-biodegradable ones, but can biodegrade fully in months or just a few years whether they are exposed to oxygen or buried deeply in a landfill, with fewer of the negative effects of PLA bags.
One thing of note about both the second and third generation bags: they need to be made with all or mostly virgin materials. Incorporating recycled materials seems to inhibit the biodegradable properties the manufacturers want to achieve.
It seems that, maybe acknowledging that “biodegradable” isn’t a perfect claim, manufacturers of these bags describe their biodegradability as an insurance policy. Recycling is best, but in case they get littered, at least they will biodegrade. While these second and third generation bags are ostensibly recyclable, what happens when those additives that are designed to speed up degradation wind up in other plastic products? Do those products begin to degrade faster, too?
With my head spinning from all this information – as Kermit the Frog said, “It isn’t easy being green” – the conclusion I’ve reached is this:
Reducing your use of trash bags is best, reuse trash bags whenever possible, and recycle where you can. And, near as I can tell, it is best to use the bags made from recycled plastic instead of the supposedly biodegradable ones.
Here in Thailand, the rubbish collectors actually sort through all the rubbish, emptying the plastic bags into the truck and then recycling the bags, so using bags that are made of recycled materials and then will be recycled again seems to go a long way to closing the loop. This manual process (documented in this 2008 blog entry) is a fascinating read in and of itself.
What about you? What plastic bag conundrums have you run into?