Biodegradable plastic bags are manufactured using petrochemicals, but they are resistant to microbial action and do not break down during normal use. These types of plastics are also compostable, which means they do not increase carbon dioxide gas.
Compostable plastic bags are made from petrochemicals
Plastic biodegradable bags can be made of a variety of materials. Some are made from plants, while others are made from petroleum-based petrochemicals. These materials are often less environmentally friendly than compostable plastic. But the difference between the two is not always clear.
Most biodegradable plastics break down in a matter of months, depending on the conditions. This is because they contain compounds that make them break down more quickly. Other compounds also break down the carbon chains that hold the polymers together.
The term oxy-biodegradable is used to describe some types of plastic. They need oxygen to break down. However, not all composting facilities accept them. Typically, these plastics will not decompose in a landfill. Rather, they end up as a contaminant.
Oxy-biodegradable plastics may be more environmentally friendly, but they have problems. Many of them have toxic chemicals in them that can leach into water and groundwater supplies. They may even be harmful to animals.
They don't break down during normal use
Many consumers think biodegradable plastic bags are a greener alternative to ordinary plastic bags. However, the truth is that they don't break down quite as quickly as they claim. They also leave behind a hazardous residue that is often hard to recycle.
There are a variety of options when it comes to choosing a biodegradable bag. Some of these products are made from natural materials, like corn starch, or algae. Others contain chemicals and additives that accelerate the decomposition process. But, most of them don't work as advertised.
Most biodegradable disposable bags need to be exposed to sunlight or oxygen in order to decompose. They're also often infused with heavy metals. As a result, some are prone to toxic residue, and even end up leaching chemicals into groundwater supplies.
While there are some types of biodegradable bags that are considered compostable, most aren't. Compostable bags can be dangerous for the environment, and they can break down too quickly for some industrial compost facilities to accept them.
They don't increase carbon dioxide gas
Biodegradable plastic bags are marketed as environmentally friendly alternatives to traditional plastics. However, research shows that they don't always break down in the way that they are advertised.
According to a study by Environmental Science and Technology, most of the plastic bags studied were still intact after three years. It seems that exposure to sunlight or water breaks down the chemical bonds that hold the molecules together.
However, the most effective way to recycle biodegradable plastics is to use them in industrial composting facilities. Industrial composting facilities have high temperatures and favorable conditions for bacterial growth. Microorganisms digest the plastic into organic materials, leaving no harmful pollutants behind.
Researchers were able to test biodegradable bags in four different environments: oceans, soil, open air and composting. They found that the plastics did not break down as quickly in each environment as they did in the others.
Some biodegradable bags require high temperatures, oxygen and UV light in order to break down. But, it turns out, the biodegradable t-shirt bags that do not break down are the ones that leave toxic residue.
They're resistant to microbial action
Biodegradable plastic bags are made from polymers which are either chemically or naturally produced. They break down into carbon dioxide or water after a few weeks or months. Some additives to the plastics can make them more degradable. However, some biodegradable plastics do not break down quickly and are therefore called durable.
These materials are not only more environmentally friendly, but they can also replace many applications for conventional plastics. For instance, they are used for agricultural mulch film. Having a biodegradable mulch film prevents long-term plastic accumulation in the soil. Another application is for use as bio-waste collection bags.
These products can be composted in industrial compost facilities or in semi-controlled home composters. Certified compostable plastics can be mixed with organic wastes for composting. Nevertheless, contamination of compost with conventional plastics is becoming a major problem. In order to reduce this challenge, there are standards in place for certification of plastics that are compostable. The standard is known as the Standard for Industrial Compostability.