Are they completely non-biodegradable?
2007-07-23 22:03:55 · 6 answers · asked by Treblacram 2 in Home & Garden ➔ Garden & Landscape
Depends on the bag. Some plastics break down quickly, others take millennia. The kind you get at the grocery stores are usually made from polyethylene film, and under good circumstances are easily recycled. Other plastic bags are thicker and do not recycle well or decompose easily.
Even those that are biodegrable need the components of air and sun to break down quickly. Absent those two factors they won't degrade for decades. Of course, neither will much else. Even things like newspaper don't decompose in airless and dark environments for a long time.
2007-07-24 01:41:39 · answer #1 · answered by thegubmint 7 · 0⤊ 0⤋
That partially depends on what you consider completely biodegradable.
Most plastic bags are made so that there are starches or biodegradable portions in the chemical structure of the bag at certain points. The entire bag isn't really biodegradable at least not for a long long time.
The best way I can explain how it works is by relating it to a chain. Think of the chain as being made up of mainly non-biodegradable oil based plastic. Then every so many links you have a link that is made out of biodegradable vegetable based plastic. The chain will only biodegrade where the vegetable based plastic links are, breaking the chain into tiny pieces. That kind of what happens to the plastic bags. They break up into a million tiny nonbiodegradable pieces.
What causes the break up of the plastic is mainly sunlight, although oxygen and bacteria can also break it up. That is partly why plastic that you bury underneath the ground lasts for so long. There is no sunlight to break it up and little oxygen. Bags that are above the ground and are in sunlight and see oxygen will brake down quicker. Plastic will also tend to get more brittle and break up as it loses plasticizer. Plasticizer is what helps keep the plastic flexible. The sun bakes the plasticizer out of the plastic. The plasticizer is what gives the plastic its "new" smell. Pretty much that is what Armor-All is...plasticizer. That's why toys and plastic tend to get brittle and fade when they are left out in the sun. Or why clear plastic turns a yellowish color. The plastic is degrading and losing plasticizer due to the sun.
If you want a truly biodegradable bag. Get one that is made out of plant-based plastic and not oil based plastic. There is one plastic that is starting to get fairly popular that is derived from corn. It is 100% biodegradable.
2007-07-24 08:44:56 · answer #2 · answered by devilishblueyes 7 · 1⤊ 0⤋
Everything is biodegradable if you wait long enough.
As plastic has been around a comparatively short time, no one actually knows how long it will take. Most guesses are about 1,000 years.
2007-07-24 08:02:40 · answer #3 · answered by dubyaaitch 2 · 1⤊ 0⤋
There are biodegradable plastics too but it is not popular and not economical. Better you paper bag.
2007-07-24 05:13:11 · answer #4 · answered by Beach bum 4 · 0⤊ 0⤋
between 15 and 1000 years
2007-07-24 05:08:59 · answer #5 · answered by ? 2 · 0⤊ 0⤋
Depending on thickness, about 100 yrs.
Go for paper bags. You can always add them to your compost.
2007-07-24 07:05:01 · answer #6 · answered by TURANDOT 6 · 0⤊ 0⤋