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| What is "Plastic Shopping Bag" |
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General
Plastic shopping bags, or carrier bags, are a common type of shopping bag in several countries. Most often these bags are intended for a single use to carry items from a store to a home: reuse for storage or trash is common. Heavier duty plastic shopping bags are suitable for multiple uses as shopping or storage bags.
Composition
Plastic shopping bags are usually made of polyethylene. This can be low-density , resin identification code 4, or most often high-density, resin identification code 2.
Although not in use today, plastic shopping bags could be made from Polylactic acid (PLA) a biodegradable polymer derived from lactic acid.[1] This is one form of vegetable-based bioplastic. This material biodegrades quickly under composting conditions and does not leave toxic residue. However, bioplastic can have its own environmental impacts, depending on the way it is produced. Recyclability of this experimental material is unproven: resin identification code 7 is applicable.
Bags made of biodegradable polythene film, which decompose when exposed to sun, air, and moisture, and are also suited for composting have been proposed as an alternative to conventional plastic shopping bags. However, they do not readily decompose in a sealed landfill and represent a possible contaminant to plastic recycling operations. Resin identification code 7 is applicable.
Environmental issues
Plastic shopping bags have advantages and disadvantages when compared to alternatives such as paper bags. Heavy duty multiple-use shopping bags are often considered environmentally better than single-use paper or plastic shopping bags. Single-use bags can be recycled, or can be reused by individuals as trash bags, storage bags, etc.
Advantages
The durability, strength, low cost, water and chemicals resistance, welding properties, lesser energy and heavy chemicals requirements in manufacture, fewer atmosphere emissions and light weight are advantages of plastic bags. Many studies comparing plastic versus paper for shopping bags show that plastic bags have less net environmental effect than paper bags, requiring less energy to produce, transport and recycle; however these studies also note that recycling rates for plastic are significantly lower than for paper.[2] Plastic bags can be incinerated in appropriate facilities for waste-to-energy. Plastic bags are stable and benign in sanitary landfills.[3] Plastic carrier bags can be reused as trash bags or bin bags. Plastic bags are complimentary in many locations but are charged or "taxed" in others.
Disadvantages
The following disadvantages have also been identified:
* Plastic bags are made of petrochemicals, a nonrenewable resource.
* Plastic bags are flimsy and often do not stand up as well as paper or cloth.
* When disposed of improperly, they are unsightly and represent a hazard to wildlife.
* Plastic bags, conventional or "biodegradable", do not readily biodegrade in a sanitary landfill, (but neither does paper due to lack of oxygen).
* Plastic bags can cause unsupervised infants to suffocate.[4]
Environmental impacts
Sturdy reusable shopping bags are EPA verified environmentally superior to single-use plastic shopping bags. A sturdy, reusable bag needs only be used 11 times to have a lower environmental impact than using 11 disposable plastic bags (providing you somehow dispose of your household waste without using bags). When unnecessary, taking single-use bags from stores is discouraged. In the case one is compelled to take a single-use bag, such bags can be recycled. Paper is accepted in most recycling programs while the recycling rate for plastic bags is very low, research from 2000 shows 20 percent of paper bags were recycled, while one percent of plastic bags were recycled. [1] Shopping bags can also be reused as trash bags, storage bags, etc. However, bags that are reused as trash bags typically still go to landfills. Current research demonstrates that paper in today's landfills does not degrade or break down at a substantially faster rate than plastic does. In fact, nothing completely degrades in modern landfills due to the lack of water, light, oxygen, and other important elements that are necessary for the degradation process to be completed. [2] Responsible solid waste disposal is encouraged. Used bags should not be littered: this is unsightly, damages wildlife and exposes fisheries to eminent danger. [3] Aquatic life can be threatened through entanglement, suffocation, and ingestion. [4] One animal dissected by Dutch researchers contained 1,603 pieces of plastic. All sea creatures are threatened by floating plastic, from whales down to zooplankton. Research proves the "Great Pacific Garbage Patch" in the North Pacific Gyre contains six times as much plastic as it does plankton. [5]
Sea turtles may mistake clear plastic bags for jellyfish. The reason that turtles ingest marine debris is not known with certainty. It has been suggested that debris, such as plastic bags, look similar to, and are mistaken for jellyfish. [6] Birds swoop down and swallow indigestible shards of plastic. The petroleum-based plastics take decades to break down, and as long as they float on the ocean's surface, they can appear as feeding grounds. "These animals die because the plastic eventually fills their stomachs," Ocean Conservancy vice president Warner Chabot said. "It doesn't pass, and they literally starve to death." [7] A study of the seafloor using trawl nets in the North-Western Mediterranean around the coasts of Spain, France and Italy in 1993/4 reported a particularly high mean concentration of debris (1935 items/km2 or 19.35 items/hectare) (Galgani et al. 1995). 77% of the debris was plastics and of this, 92.8% were plastic bags. [8]
Nearly 80% of litter in the ocean comes from land-based sources. [5] Most of the land-based debris is conveyed to oceans via urban runoff through storm drains. The main source of plastic bags in the ocean is from urban runoff. [9]
Recycling
According to the United States Environmental Protection Agency, only 1% of plastic bags were recycled in 2000.[2] When one ton of plastic bags is reused as something else other then plastic bags or recycled, the energy equivalent of 11 barrels of oil is saved.[2]
According to the UK government Department for Environment, Food and Rural Affairs, there are several problems with plastic recycling, and in particular plastic bags:[6]
* the high volume to weight ratio of plastic means that the collection and transport of this waste is difficult and expensive
* there are often high levels of contamination in plastic making the recyclate less usable, especially where food products are involved
* there is a very wide range of plastics in use and segregation is difficult
* the market for using recycled plastic is underdeveloped
References
1. ^ Notes from the Packaging Laboratory: Polylactic Acid -- An Exciting New Packaging Material
2. ^ a b c Questions About Your Community: Shopping Bags: Paper or Plastic or . . .?
3. ^ Slate Explainer, "Will My Plastic Bag Still Be Here in 2507?" 27 June 2007.
4. ^ [http://www.cpsc.gov/CPSCPUB/PUBS/5064.html Children Still Suffocating with Plastic Bags}
5. ^ Faris, J. and Hart, K., Seas of Debris: A Summary of the Third International Conference on Marine Debris, N.C. Sea Grant College Program and NOAA, 1994, title page.
6. ^ What happens to waste: Plastics & plastic bags
7. ^ Planet Ark: Coles Bay, Australia's First Plastic Bag Free Town
8. ^ Oz considers bag ban
9. ^ Govt urged to act on plastic bags
10. ^ http://news.nationalgeographic.com/news/2008/04/080404-plastic-bags.html
11. ^ Report on Bhutan's Happiness Formula on BBC website
12. ^ "China bans free plastic shopping bags", AP Press via the International Herald Tribune, January 9, 2008
13. ^ Irish bag tax hailed success
14. ^ RTÉ News - 'One plastic bag now costs 22c'
15. ^ Globes [online] - Ministerial c'tee okays charge of NIS 1 per plastic bag
16. ^ bagsNOT
17. ^ Green Clubcard Points
18. ^ IKEA Website
19. ^ uktv Documentary
20. ^ London Councils' press release 13/11/2007
21. ^ Cambridge News website
22. ^ Marks and Spencers 5p per bag
23. ^ Budget at a glance
24. ^ AB 2449 (Levine) Plastic Bag Litter and Waste Reduction
25. ^ Banning Plastic Bags From Your Community
26. ^ IKEA U.S. 'Bag The Plastic Bag' Initiative Asks Customers to Stop Plastic Bag Waste
27. ^ BBC NEWS | Africa | Zanzibar islands ban plastic bag
