We all know plastics aren’t biodegradable and that’s bad, so why can’t we just use chemical science to break them down ourselves?


We all know plastics aren’t biodegradable and that’s bad, so why can’t we just use chemical science to break them down ourselves?

In: 7

We can, but the problem is you end up with a soup of toxic chemicals that cant be economically reused. It all comes down to money – it is cheaper to burn or bury the plastics than to resuse them – it may also be greener to bury them as at least the CO2 is locked up for a longer time.

What it breaks down into can be worse. When you depolymerize a plastic, you get it’s components. There are some bacteria that can eat plastic but it’s not really for prime-time yet.

Biodegradable plastics exists, but are more expensive and not always suitable
Burning will pull co2 in atmosphere
Burying or landfill is never done properly because of coruption, fraude and money and eventually get into the sea.

The wonders of plastics is what makes them such a pain in the butt to try to undo: they’re quite stable and freakishly large molecules, so it takes quite a bit of energy to undo them into something you can easily work with. It can be done, sure, but the costs, both in terms of money and actual resources, scale terribly.

Well we can break them down it to pellets that can be recycled into other plastic products and I think that’s probably better.

There are some plastics that are biodegradable.
Most of them are only really compostable under certain circumstances though.

We can do a lot of stuff with other plastics too, but it is always about cost and revenue. A high percentage of clean plastic material can be recycled, but it has to be quite clean indeed. And washing/sorting ist costly again, unfortunately.

Recycling depends on the ease of breaking things down so that you can rebuild it back up. Eg., like a lego set, you can break a completed model down to its pieces, and then reuse it to make another lego set.

For aluminum, you shred it to pieces, remove unwanted pieces and melt it back to new aluminum blocks.

For paper, you shred it back into pulp, bleach it, and remake back into post-consumer paper.

Compared to other recyclables, plastic is much more complex. It has lots of different chemicals that make it up, so its much harder to break apart cleanly.

Why don’t we artificially create a micro organism that can completely get rid of plastic?

Cost is the real driving reason. Even if you can recycle plastic effectively, it’s still cheaper to dump it somewhere and make new plastic.

My question is, why can’t we make hemp plastic instead?

I think the best answer is that we are using chemistry and biology to find the solution, but “plastics” aren’t just one chemical and there are lots of things that go on with chemistry that make it difficult to target one set of compounds without also targeting similar but useful (often even necessary) similar chemicals. And, of course, that we like plastics so much for that reason that they don’t easily break down (it is a selling point for using them), so finding a way to cause them to destruct naturally is precisely the opposite of why we make them in the first place.

Some plastics are biodegradable, and some plastics can be targeted by biological modifications that create things that will biodegrade when they do not yet exist. It takes time, money, and work to find an answer to the problem of how to make something which will destroy this stuff out in the wild world that won’t also cause even bigger problems and/or destroy it where we don’t want it to happen.

There is no “Poof, look at the simple answer to this really complicated problem”. We wish, but it isn’t no matter how much we want.

Not that much of an answer but!! I found out an enzyme was recently created that can break down plastics!


We can turn just about anything into just about anything else, given enough time and energy. The problem is that those things cost a lot of money.

Pretty much all of our environmental problems are not caused by a lack of good alternatives, they are happening because all of the other options are more expensive. Whenever you can push the costs off onto “someone else,” there is no incentive to do things like make sure the waste from the products you produce or consume doesn’t stick around in the environment doing damage for thousands of years.

This is why you absolutely _need_ good regulations. If you don’t have them, then anyone who makes or sells anything will find a way to do it such that they get the maximum possible profit, and everyone else bears the maximum costs. To give a simple example, if you have some gold on your property, the cheapest way to extract it is to grind up the gold ore, mix it with water and cyanide, and then filter out the liquid and sprinkle zinc dust on it to make the gold precipitate out. What do you do with all the leftover cyanide? Well, you don’t want to dump it on your own property, so the cheapest thing to do is dump it on your neighbor’s property, or in the closest river. Obviously that’s bad for everyone else, but if you have no conscience and nobody stops you from doing it, it’s the most economical way. Of course, that’s only true because you are ignoring the _externalized cost_ – the cost someone else pays (your neighbor, or whoever else needs that river water, or future generations).

This is the problem for all environmental issues – people who make money off of some product or service find ways to push as many costs as possible onto other people. The less organized and weaker those people are, the better this works. If the local oil refinery dumps chemicals onto the ground in a poor neighborhood, how hard is it going to be for the people living there to stop them, or to be compensated for the damage? If the people show up and start dumping their trash on the oil refinery’s property, how likely are they to get away with it? Those power imbalances create situations where it becomes extremely easy for companies to externalize costs and spread them out to everyone else, while making billions for themselves.

CO2 in the atmosphere is another great example. The oil industry makes hundreds of billion of dollars per year in profits, but they can only do that because the hundreds of _trillions_ of dollars that dealing with the effects of climate change will cost are going to be paid by everyone else. If they had to pay that cost to produce gasoline or coal (for example), they’d never do it.

With plastics, we don’t really know the long-term externalized costs. We know that the plastic doesn’t ever disappear, it just breaks down into smaller and smaller particles. We know those particles are everywhere now – in you, in unborn babies, in all the food we eat, in our water, even in the air. We have no idea what kind of harm that is going to cause, or how to deal with it.

The plastics industry became very wealthy selling these products, and we enjoyed using them, and it all seemed like a great idea because _someone else_ is going to pay the true costs.

We could replace just about all of these plastics with biodegradable ones. It might cost twice as much, so now that $1 toy you bought at the dollar store would cost $2. Would it be worth it? I think it would be. But if you put a regular person in the store and show them two of the same item, one costs $1 and one costs $2, most people will go for the cheaper one. Maybe if you educate them and teach them how bad those non-biodegradable plastics are, some people would go for the more expensive option, but in general the cheaper one wins.

An easy way to fix it is to tax single-use and non-biodegradable plastics. Make them cost as much or more than the biodegradable options, and suddenly those externalized costs are put back on the producer and the consumer, and they’ll make the environmentally responsible choice out of their own self-interest.

Because we don’t have laws in place that make manufacturers think about the whole product lifecycle from resource extraction to end of use. Force a plastic company to create a plastic and the chemical that breaks it back down for reuse and we might see a whole shift it materials sciences.

Instead of breaking plastics down into an inertbiodegradable form. Some people are trying to reuse the materials.

Plastic construction bricks (not Legos)

Plastic recycled into clothing

Plastic into paper

Now, I have no idea how these secondary products impact the environment (either in production or as waste) but it *is* an alternative to burn or bury.

1. There are actually biodegradable plastics, they’re just less cheap and available, because other plastics are made from byproducts from fossil fuel processing. There’s a lot of THAT, so we have to do SOMETHING with it. It isn’t useful for much *except* plastic, which is why plastic is so cheap to produce. So as we scale back on fossil fuel consumption, you will see a natural shift to biodegradable plastics like PLA, as the waste material from corn starch will eventually become cheaper than the plastics from fossil fuels.

2. We can and we’re working on it, but to do so in a way that concerts all of the chemicals into stable and safe forms to have in the atmosphere in concentration is the problem. It always breaks down into *something* and we don’t want that something to be noxious fumes, or to poison the water supply. So whether we’re using chemicals or microorganisms to break it down, we will need to make sure it’s done in a safe way. Plus, consider the extra stuff that’s hidden away in the plastic goods. Like the little batteries in a child’s watch, or foil on the inside of a package. How will those things interact with the breakdown process? What would happen if the chemical or microorganism were to leak from the plastic eating zone, does that hurt the local environment too?

Lots of things to consider. It’s by no means an easy problem to solve, which is why there are so many smart people working and thinking on it.

We can, literally this study just came out this week: https://www.nature.com/articles/s41586-022-04599-z

What are plastics made out of?

There are fungi that are adapting to eat plastics. Oyster mushrooms from the grocery store are ok at it. Not very efficient. Other kinds are better in lab conditions with certain plastic types.

There are also machines that “melt” the plastics down to its base form to reuse as fuel. A new-er technology and therefore crazy expensive, but they’ve been popping up in Japanese shipyards, so people can trade their plastic for boat fuel.

Hey OP, you might find this interesting… tress are made of a type of plastic… they polluted the entire planet and caused massive global cooling that destroyed massive amounts of life.

After a while a bacteria evolved that could actually eat the bioplastic called lignin and then the issue was resolved.

The same thing is true for our plastics, as soon as we develop a bacteria that can eat the plastic we should solve the problem then, so long as the bacteria produces waste that can balance off against carbon in the air