How Long Does It Take Plastic to Break Down in a Landfill

We are 100% in favor of recycling as much plastic waste as possible. Still, it is not unusual for our team members to cringe at some of the things recycling proponents present as fact. A good example can be found in the many different estimates of how long it takes plastic to break down in a landfill. The estimates are often presented as facts even though they are not.

We have seen estimates of as little as 10 years for some types of plastic bags and thousands of years for some other types. Here’s the thing: if it actually does take a thousand years for a piece of plastic to decompose, we’ll never know it.

It Does Take Longer

We may not be able to say for sure just how long it would take a particular type of plastic to decompose. But we do know, through simple observation, that it takes longer than organic waste. Just throw some potato skins in your garbage and wait a day or two. Your nose will tell you they are already decomposing. Meanwhile, the plastic lid you tossed in the garbage the day before is still fully intact.

For that reason alone, recycling plastics of all types, especially industrial plastic, is worthwhile. Organic waste effectively turns into soil as it decomposes. It becomes a food source for plant life and certain types of creatures that live in the soil. Non-organic waste is a different matter.

Why It Takes Longer

Let’s just say the estimate of 10 years for a plastic garbage bag is accurate. Why does it take so long for that bag to break down compared to a paper bag? It has to do with the chemical compositions of both.

Plastics are polymers made primarily from crude oil. Polymers form excessively strong bonds during the manufacturing process. These bonds are what make plastic so durable.

One of the few things that can break polymer bonds is UV radiation. UV light penetrates plastics and begins to break the bonds between molecules. But in a landfill, plastic waste is exposed to very little UV light, if any at all. That leaves the decomposition task to water and other constituents in the soil. None of them work as effectively or as quickly on plastic as UV radiation.

Complete Decomposition May Not Be Possible

Although scientifically unproven to this point, it has been suggested that complete decomposition may not be possible with some types of plastics. As the thinking goes, polymer bonds are so strong that even decomposed plastic leaves behind tiny particles that will remain forever.

If this is true, those particles present in soil could ultimately end up in groundwater. That’s something we probably want to avoid. Obviously, we need more research to prove whether the complete decomposition hypothesis is true. If it is, this is all the more reason to do a better job of recycling.

Doing Our Part

Though we cannot prove definitively how long it takes plastics to decompose in landfills, we do know it takes much longer than organic waste. That is a sufficient reason to recycle. Here at Seraphim Plastics, we are doing our part. We buy industrial scrap plastic from customers in seven states, including Tennessee and Michigan.

If you are interested in keeping slowly decomposing plastics out of landfills, we would like to speak with you. We buy a full range of industrial plastic waste including plastic purge, cut-offs, buckets and totes, and even baled PET bottles. If we can buy your scrap plastic, we will offer a reasonable price and come directly to you for pickup.