eli5 why is plastic inorganic


how is anything inorganic , if everything we have is from the earth itself and is therefore natural?
part 2 of the same question is why are somethings then non biodegradable?

In: Chemistry

It isn’t.

Plastic is made with organic chemistry. It’s basically dead algae from ages ago.

>how is anything inorganic

Organic means “made from carbon”. That excludes stones and metals. They are still natural, but not organic.

>why are somethings then non biodegradable?

To be biodegradable there needs to be some animal/bacteria/fungus that can eat and decompose it. For stuff like plastic that isn’t the case because the situation that creates plastic doesn’t happen if humans aren’t involved, so no natural plastic eaters could evolve (considering that humans are very new to this planet, and plastic even newer)

In Chemistry:

* Organic = molecules containing carbon-hydrogen bonds, typically forming carbon chains or rings.
* Inorganic = everything else.

In Chemistry terms, plastics are organic, since they are made from carbon chains containing hydrogen atoms.

A more ‘common use’ of the term Organic is ‘relating to or derived from living matter’. Under that definition, plastics are Inorganic.

Another meaning of Organic is something produced without artificial pesticides, fertilizers, etc. This doesn’t really relate to plastics.

Basically, plastics are organic materials in a Chemical sense. A lot of people confusingly (and mistakenly IMO) use organic to mean “natural” or not man-made and so might call plastic inorganic. But they’re wrong.

Chemically, plastic is organic. Its molecules all come from fossil fuels, usually natural gas.

“Organic” as used in farming and food has a different meaning, it just means you don’t use synthetic pesticides (even though those pesticides are, chemically, organic compounds), and that you fertilize with blood and poop rather than inorganic salts like potassium nitrate and ammonium sulfate.

You’re misunderstand the definition of inorganic. Inorganic refers to thing that are/were part of a living thing. Your body is organic, your corpse will be organic, hemp clothes are organic, cotton is organic, but oil based textile aren’t. It’s not living nor the residue of a living thing. For that matter, plants are alive and thus pretty much all plant based stuff is organic.

For your second question, biodegradable mean that something can easily be recycled by nature. In most cases, nature use bacteria and insects to degrade stuff. When you throw a piece of wood, insects and bacteria munch on it until nothing is left but the poop from these things. Same thing with bits of food and usually the vast majority of non-treated organic materials.

Non biodegradable stuff is usually something that cannot be degraded by insects and bacteria. Instead they can only rely on the wear of time (wind, water,…) to slowly erode themselves. Depending on the material, it can take more or less time for it to completely degrade. Plastic is of course not the only non biodegradable stuff, stone aren’t either.

The big issue with plastic is that we produce tons of it, throw away most of it, and insects and bacteria have no idea how to degrade it. Thus they just keep stacking in landfills and oceans.

On the contrary, plastic is described as a product of organic chemistry because it is made of chains of hydrogen and carbon atoms. “Organic glass” (acrylic) as opposed to regular silicate glass. Plastics are not decomposed by living organisms because these materials have only existed for a hundred years, and organisms haven’t adapted through their evolution to process them.

First, if we are talking about recognised definitions, not everything that’s on earth is referred as “organic”. Rocks are definitely inorganic, as their composition does not involve covalent carbon-based compounds. Maybe the term you are thinking about is “natural”.

Depending on your definition of organic, plastic can be considered both organic and inorganic: scientifically speaking, as plastic is made of hydrocarbons, it is considered part of organic compounds, studied by organic chemistry. Generally speaking, as normal plastic needs a very long time to degrade and is not readily biodegradable, we refer to it as “inorganic”, while we should really be saying “non-biodegradable”.

As to why it is like this: things ultimately biodegrade because a series of organisms feed on their components at various degrees, determinig their recycling in the trophic chain.

In the case of plastic, almost no living organism has evolved to metabolize its components, mostly because, before the advent of man and the industrial revolution, they were generally unavailable to lifeforms.

This is why we are pushing for biodegradable plastic made of vegetables (like corn), so that organism can actually feed on it.

The term organic have multiple definitions. Plastic fits under some of these definitions but not all. In chemistry plastic is considered organic because it is made up of hydrogen carbon bonds. Although there are plastics which does not fit this definition either as it is made up of for example carbon and chlorine. But if you use the term organic in the food industry then it have a completely different meaning which would not include most plastics because most plastic is man made and is not found naturally in nature.