Traditional plastic bag
What is the harm of traditional plastic bags to our environment? Let me calculate. The average service life of disposable plastic bags is 12 minutes, and 2 million such bags are used every 60 seconds worldwide. Polyethylene bags are made from non-renewable resources and are harmful to the marine environment because they have never been biodegradable. Instead, they will be broken into smaller and smaller pieces over hundreds of years, causing countless damage to natural ecosystems.
In short, certain organisms are degradable when they are broken down by an organism (such as a fungus or a bacterium). Biodegradable bags are made from plant-based materials, such as corn and wheat starch, not petroleum. However, for this plastic, the bag must have certain conditions to begin biodegradation. First, the temperature needs to reach 50 degrees Celsius. Second, the bag needs to be exposed to ultraviolet light. In a marine environment, it is difficult to meet one of these two conditions. In addition, if biodegradable bags are sent to landfills, they will decompose without oxygen to produce methane, a greenhouse gas that has a warming capacity that is 21 times that of carbon dioxide.
Degradable or "oxygen-degradable" plastic bags
Degradable items do not have biology as a key part of the decomposition process. Degradable bags cannot be classified as biodegradable or compostable. Instead, the chemical additives used in plastics can make plastic bags break faster than standard plastic bags. Essentially, a bag that is touted as 'degradable' is absolutely useless and even worse for the environment! The degradable bag will become faster and faster, more and more delicate, and even still It poses a serious threat to marine life. Microplastics enter from below the food chain, are consumed by smaller species, and then continue along the food chain as these smaller species are consumed. Tony Underwood, University of Sydney Professor Underwood described biodegradable plastic bags as "not many solutions unless we are happy to convert them all to pallet-sized plastic, not plastic bag-sized plastic.
Compostable Plastic Bag
The term "compostable" is incredibly misleading to the average consumer. You would think that a bag labelled "compostable" means you can put it in the backyard compost with fruit and vegetable residues, right? Wrong. Compost bags can be biodegradable, but only under specific conditions. Compostable bags need to be composted in specific composting facilities and are rarely available in Australia. Compostable bags are usually made of plant materials and when processed at these facilities, they will return to their basic organic content, but the problem is that so far there are only 150 such facilities in Australia.
The biodegradable bag supplier believes that plastic bags, biodegradable, degradable and compostable bags cannot be placed in standard recycling bins at home. If they do, they can seriously interfere with the recycling process. However, your local supermarket may recycle plastic bags. Some supermarkets can also recycle torn or no longer used green bags.