I was reading something this morning about how the City of Philadelphia is considering baning plastic bags completely. It seems that those thin plastic bags you get from the grocery store are public enemy number 1 when it comes to the battle over the protection of the environment. It is truly fascinating to see the things that people focus on, anybody up for re-arranging some deck chairs?
So why not, there is little else going on these days. I mentioned the above to my lovely and talented wife, who stated that she got a “degradable” plastic bag from the local organic grocery store. So I examined said bag and found the statement “This bag will degrade into many small pieces when exposed to sunlight.”
explanation on plastic bag about why this bag is "green"
I don’t know if you can read that or not.
Many people might call these bags “biodegradable” which they are not. “Bio” would indicate that some living thing could act on the structure of the plastic, breaking apart into different compounds and base elements. I would call these bags oxi-degradable, which means that sunlight will oxidize the carbon chains into CO2 thus breaking apart the structure of the plastic. It also mean in an non-oxygen environment, such as being buried in a land fill, or under water somewhere, these bags will be every bit as resilient as their non-degradable counterparts.
The other question is time period. Anything will degrade over time, the question is how long? One day, one week, a year, a decade… To answer this question, I staked the degradable plastic bag out in full sun light.
degradable plastic bag in full sunlight
I’ll post a follow up when it dissolves into many small pieces.
Update: July 1, 2009. No noticeable degradation.
Update 2: July 13, 2009. No noticeable degradation.
Update 3: July 31, 2009. Bag is falling apart:
degradeable plactic back after 6 weeks in the sun
After 48 days, the bag is disintegrating rapidly. I will also admit that we have had a wet rainy summer and the sunlight has not been as intense as it normally is. That being said, I stand by my assertion that if these bags are buried in a land fill or in an anoxic environment, they will not degrade at all.
Still, it did do what the manufacture said it would, so I’d say they are an improvement in plastic bag technology.
Like you, I have some doubts about this bag.And I think that deck chair would look better over there, so as to hear the ship’s band better
Are they just playing with words? breaking up into many small pieces may just mean a physical change. Im not an expert on the subject but I would like to ask if these bags undergo chemical change when exposed to sunlight? I’m curious to see the result of your experiment, Paul.
I suspect it may be a case of Greenwashing. Many plastics degrade in UV, it is just a matter of time. Most polyethylene or polypropylene takes a good 12-36 months or even longer to begin to break up.
say no to plastic bags