How Long Does It Take For Plastic To Decompose?

How Long Does It Take For Plastic To Decompose


Traditional plastic is everywhere we look, from toys and food packaging to building materials, toiletry packaging and soft drink bottles. How Long Does It Take For Plastic To Decompose? It takes very long for plastic to decompose. However, awareness is increasing of the negative impact plastic has on the environment due to its toxic makeup and the time it takes to break down.

Plastic can take anywhere from 20 to 500 years to decompose or break down in any environment, including landfill. When plastic decomposes, it breaks down into small pieces that may not be visible to the naked eye, however, these small pieces of plastic will never fully decompose and will potentially contaminate water, soil and air.

How Long Does It Take For Plastic To Decompose?

What Is Plastic Made Of?

Traditional plastic – the type your soft drink bottles, shampoo bottles, plastic bags and takeaway containers are made from – has been around since 1907. However, awareness is rising of the negative contribution of plastic to the environment and landfill so people are wanting to find out more about plastic.

Plastic is made from materials such as crude oil, gas, coal, cellulose and salt which are seen as natural materials or resources. The materials undergo a refining process which essentially is then treated by heat and ‘cracked’ before being combined with other materials to create different plastic types to turn into plastics you can use.

‘Cracking’ means the degradation of the materials by heating without oxygen – this is the main process breaking down the complex carbons into smaller ‘pieces’ creating the new chemicals for end result.

Unfortunately, because crude oil and natural gas are the main ingredients, this makes the plastic in many cases toxic either to people, animals or the environment when breaking down. Manufacturing products from materials such as crude oil is also bad for the environment, releasing carbon dioxide into the air, and oil itself being toxic to animals and the environment on many levels.


What Is The Lifecycle Of Plastic?

Plastic doesn’t ever completely break down, ending up in small particles after decades to centuries in the soil, water or air. With countries such as Australia producing almost three million tonnes of plastic a year, what is the lifecycle of traditional plastic? or how long does it take for plastic to decompose?

In some ways, the lifecycle of plastics is really never ending as it doesn’t ever completely decompose. It’s also important to understand that different plastics and products breakdown at different rates. The lifecycle of standard plastic items is as follows:

  1. Manufacturing process – gathering materials, combining and creating the basic plastic.
  2. Production process – molding, adding dyes or additives, changing to heat resistant or bacteria resistant.
  3. Plastic usage – how we use it i.e. toys, water bottles, packaging.
  4. Some plastics can be recycled or reused – think water bottles that can be recycled, reusable water bottles.
  5. Non-recycled plastic ends up in landfills or the natural environment – around 90 per cent or more of all plastics end up like this.
  6. Plastic takes up to centuries to break down into small particles that will never disappear.


Why Does Plastic Take A Long Time To Decompose?

Why is plastic so hard to decompose? That’s a common question people may have when looking at the negative impacts of plastic on the environment. Most of this comes down to how plastic is manufactured and the materials it contains.

Most plastics are made of polyethylene terephthalate or PET, which is virtually indestructible as bacteria can’t break them down. For materials to be able to break down or decompose, typically they need to contain organic or raw compounds that can be broken down by microbes or UV light. Nature needs to recognize them!

Plastic made from petroleum which is the end product of millions of years of once-living organisms decaying, has a manufacturing process which completely changes this material so that it can no longer be broken down.

Plastics made from propylene (most plastics) are unable to be broken down because they are heated which makes the individual chemical components link together, forming extremely strong carbon-carbon bonds with each other. Nature doesn’t understand this and so it cannot be broken down.

How Long Does It Take For Plastic To Decompose 1

What Types Of Plastic Take The Longest Time To Breakdown?

Plastic breaks down at different rates based on the type, the materials it contains and its size and usage. This means that plastic can take between 20 years and 500 to break down into smaller particles which will never completely disappear even if they are unable to be seen.

Here are some products and the time they can take to breakdown based on where they are disposed of, any other materials inside or on (such as dye or additives):

–          Plastic bags can take around 20 years yet can be extremely harmful to wildlife including ocean life.

–          Coffee cups may take around 30 years and, as you can imagine, they are widely used globally and so contribute greatly to landfill.

–          Plastic straws may take up to 200 years which is why many countries are introducing legislation to get rid of plastic straws. They can also pose great risks for wildlife and ocean life.

–          Plastic bottles – such as spring water or soft drinks can take up to 450 years. Think about how widely used these are and the potential global impact of these! They can often be recycled, yet many people don’t bother to recycle.

–          Disposable nappies/diapers take a very long time to break down – around 500 years in many cases! They require oxygen AND sunlight to break down so don’t break down well in landfill. They can also contaminate groundwater.

–          Coffee pods and toothbrushes can also take up to 500 years which is why you will see more and more options for eco-friendly coffee pods and toothbrushes (think bamboo!) on the market.


Why Is Plastic Harmful To The Environment?

Traditional plastic is all around us in our everyday lives, from the cutlery you receive at a takeaway to the bag you take your trash out in. Unfortunately, many types of plastic are not recyclable, compostable or biodegradable and it’s important to understand which types you are using and any available alternatives.

Why is plastic so harmful? Because it can literally harm wildlife is the simple reason. They can get caught up in plastic – on land and in the ocean – or they can consume small pieces of plastic which will kill them either via choking or other health consequences or injury.

There are many types of traditional plastic out in the world, including many disposable products. From packaging and food service to trash bags and shopping bags, plastic is everywhere. Many Governments around the world are starting to take action against the use of disposable plastics, with the environment front of mind.

There are more and more plastic alternatives to common products such as plastic or trash bags, food service, coffee cups, straws and others to try and combat this issue. Where plastic can be recycled, it should be, but unfortunately many people will simply throw it into the environment (littering) or landfill.

Plastics are classified in numbers from 1-7 which also helps identify their level of recyclability. There are many different types of plastic that may or may not be recyclable and may or may not release toxic chemicals when exposed to extreme temperatures or landfill. You can read more about the types of plastics and how they are best disposed of in this article.

How Long Does It Take For Plastic To Decompose 

Why Is Plastic Harmful To Humans?

Unfortunately, as the years go on, more and more plastic products have been found to be toxic to humans. This is due to the chemicals added to plastics and then absorbed by humans, such as from water or other bottles. Microplastics entering the human body through ingestion or inhalation can also be toxic.

There have also been studies shown that certain chemicals found in plastic can leach out of the plastic and into food and beverages. This has been linked to health problems such as reduced fertility, cancers or metabolic disorders.

Remember when we found out that BPA (bisphenol A) was toxic and often found in products such as bowls and even baby bottles? BPA has been linked to cardiovascular problems, impacts on the brain and prostate and even reproductive and immune system.


How Do You Know What Type Of Plastic You Are Buying?

If you’re concerned about the impact of plastic on humans, wildlife or the environment, it’s important to know what plastic you are purchasing. It’s also important to understand if it can be recycled or reused and if there is a bioplastic alternative.

There are seven main types of plastics, with PET being the most common.

  • Polyethylene terephthalate (PET) commonly used for soft drink and water bottles
  • high-density polyethylene (HDPE) commonly used for harder wearing applications like shampoo bottles
  • low-density polyethylene (LDPE) commonly used for softer applications like grocery bags and cling wrap
  • polyvinyl chloride (PVC) commonly used building construction applications like pipes
  • polypropylene (PP) commonly used for bottles, toys and car parts
  • polystyrene (PS) used for packing, 
  • and other resins.


You can read more about the 7 types of plastics in this article. Each should also have a symbol somewhere on it (often the base) to show you what number it is. This also helps in disposing of the plastic.

How Long Does It Take For Plastic To Decompose.


Traditional plastic is unfortunately everywhere, and not all products currently have a bioplastic alternative on the market. This means that it’s important to understand what plastics you are purchasing, what products have plastic materials, how to dispose of them and if there is an alternative available.

Plastic can take 20 to 500 years to break down, but will never actually completely break down. Unfortunately, traditional plastic breaks down into smaller pieces but will never completely disappear. This means that it can impact wildlife, soil and water negatively.

Different types of plastic break down at different rates, some can be recycled and many cannot. You can identify the type of plastic with the number and symbol on most products. You should also understand potential health impacts on humans from certain plastics such as BPA and ensure you don’t have these products in your household.



    We’re on the mission to research the best sustainable products and these are what we found, these are the questions that we are asking. Disclaimer, we are not scientist but we are heavy researchers and we are passionate about sustainability.