Exact Answer: 20 – 600 years

Plastic is a blessing and harmful at the same time. It has improved our way of life, but it has also presented us with a major dilemma. Our everyday essential items are made of plastic and at this point, it seems that leading a plastic-free is impossible.

Plastic is ubiquitous, and it’s designed to survive for decades, if not centuries. It’s beneficial, yet it’s awful for the amount of garbage it generates. This dilemma by environmental scientists and citizens of the world has led to the basic question: how long does it last?

How Long Does It Take Plastic to Decompose - Plastic is a blessing and harmful at the same time. It has improved our way of life, but it has also presented us with a major dilemma. Our everyday essential items are made of plastic and at this point, it seems that leading a plastic-free is impossible.

How Long Does It Take Plastic to Decompose?

Depending on the composition and structure, plastics might take anywhere from 20 to 500 years to degrade. Furthermore, the rate at which a plastic degrades is determined by its exposure to sunshine. 

Plastics, like human skin, absorb the sun’s ultraviolet (UV) radiation, causing the molecules to break down. This is referred to as photodegradation, and that is why landfills’ depiction commonly includes plastic waste to the light in order to hasten the disintegration procedure.

Single-use plastic like straws, for example, takes roughly 200 years to degrade. Plastic water bottles composed of polyethylene terephthalate (PET), a common form of plastic, on the other hand, are expected to take 450 years to degrade.

MaterialEstimated Decomposition  
Cigarette butts5 years
Plastic bags20 years
Coffee cups30 years
Plastic straws200 years
Soda can ring400 years
Plastic bottles450 years
Toothbrushes500 years
Disposable diapers500 years
Styrofoam500 years
Fishing line600 years

When all of this plastic winds up in landfills, landfills are designed to make biodegradation difficult. To make place for more garbage, landfills are compacted and covered with dirt every day, so the sun barely has time to reach the waste before another layer is added.

Landfills are truly unpleasant, and they are also extremely harmful to the ecosystem, releasing poisons and greenhouse gases into the ground and air. In addition, non-recycled plastic that does not make it to a landfill lastly goes into our water bodies.

Why Does It Take That Long to Degrade Plastic?

It’s simple: plastic isn’t a natural material. Plastic is not found in nature, even though it is made from petroleum, which is extracted from naturally occurring crude oil. 

There’s a lot of physics behind it, but the main difference is between the chemical bonds of plastic and the molecular bonds of organic things found in nature. The carbon bonds in plastic aren’t the same as those found in nature, making it more difficult and energy-intensive to break them down. 

Recent Plastic Innovations

However, there are new types of plastic on the market: bioplastics, or biodegradable plastics. Bioplastics are named by their capacity to biodegrade quickly, despite the fact that they are not made from natural materials. It has to do with the chemical bonds we discussed before.

There are 3 types of bioplastics:

  1. Degradable — as previously said, all plastics degrade, yet even the tiniest broken-down particles of plastic may not be able to return to nature. Chemical additives are required to aid in the breakdown of this material.
  2. Compostable- Bioplastic may decompose spontaneously into the water, carbon dioxide, and biomass in a garden heap (in certain cases) or at commercial compost sites (in most cases). The nutrients will be absorbed by the soil once it has thoroughly decomposed, and no harmful residue will remain.
  3. Biodegradable- It is comparable to compostable, except it takes longer and can leave hazardous residue and microplastics behind.

Plant-based polymers have been developed by some scientists utilizing maize or sugarcane as basic material. Scientists have changed the chemical linkages in petroleum-based polymers to make them simpler to break down by nature.

Conclusion

Although all plastic is biodegradable, the process takes a very long time. We have discarded 6.3 billion tonnes of plastic since industrial manufacturing began in the 1950s, yet only 600 million tonnes have been recycled. The remaining 4.9 billion tonnes were either disposed of in landfills or discharged into the environment, putting animal and marine life at risk. In an attempt to solve this problem, bioplastics have emerged as a possible solution.

References

  1. https://www.tandfonline.com/doi/abs/10.1080/10601329308021259
  2. http://publish.illinois.edu/meaganb2/files/2018/05/Borgsmiller_ResearchPt3.pdf