Glass vs. Plastic: Which is better?

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Glass vs. Plastic: Which is better?

By Joe Laur
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In the great #recycling debate, which is better? Glass, or plastic? via @Greenopolis
Thursday, May 20, 2010 - 11:14am


Glass right? It’s been around for centuries, is safe (unless you cut yourself), non toxic, and easy to recycle. Plastic is mainly derived from fossil fuels, can have nasty additives that can leach into our bodies, and is less recyclable in many cases. Right?

Well I wish it was that simple. Glass-good, plastic-bad, has a nice ring to it. But alas, it’s more situational than that.

First of all, glass is heavier than plastic, so it costs more and burns more fuel to transport. Glass is also not recycled as often as you would think, at least not back into containers. Again it’s the weight factor. Unless there’s a local glass factory, it’s not cost/fuel effective to truck all that heavy glass around. So most of it gets ground up for pavement additive and landfill cover. Which is not all bad, because glass is pretty harmless in the environment - it’s just melted sand.

Plastic can actually have a lower environmental footprint in some cases, due to its light weight and how far it’s shipped. Depending on the number plastic, it’s fairly safe (Remember 1, 2, 4, 5- use ‘em and you stay alive; numbers 3, 6 and 7- use ‘em and go straight to heaven) and very recyclable material. Even after it can’t be recycled any longer, it can be cleanly combusted in modern waste to energy facilities. And unlike “clean coal” they actually exist, all around the world.

Take the common bottle of milk. I have a local dairy that sells milk in glass bottles with a return deposit. In this case, glass is a better choice- locally shipped and reused many times, it has a lower footprint. But if the local milk is not available and I’m buying a bottle from a more distant dairy, plastic might be better. Milk is sold in #2 HDPE bottles, which are untinted and very recyclable and very recycled. They also don’t break (we’ve had more than one glass bottle of milk slip and crash to the floor) and can be reused as sap buckets, water jugs, scoops and so forth. I can also buy milk in cardboard cartons, but they are coated with plastic and can’t be recycled at all. They can be reused as building blocks, brick makers and plant pots, but most of them get landfilled or burned.

Same for pop, soda or whatever you call it in your region. Glass bottles weigh twice as much as #1 PET, so if the beverage is local, glass is great. But #1 PET is also recycled, and can be shipped longer distance for the same amount of fuel. And now PET is being made into new bottles, like ReSource and Pepsi products. Promising new “green chemistry” is able to break the polymers down and rebuild them, so that the plastic can be recycled nearly infinitely.

Some products, like wine, just taste better in glass and can interact with plastics after 8 months to a year as they oxidize. On the other hand, freezing meats and veggies in glass does not work so well, and plastics keep meats from freezer burning. I seal my wild caught fish and venison in #4 LDPE bags filled with water.

And glass is just slightly more recycled than plastic overall; about 28 vs. 24%. In states without bottle deposit bills, glass is slightly less recycled!

So if I’ve confused you even more, good. Because we need to ask questions, look at the whole system and leave simple answers for the simple. Glass, aluminum, steel, and plastics all have a use in the right place and time. You could buy your milk in glass, yogurt in #5 PP plastic, and orange juice in cartons. The main effort should be to reduce, reuse, recapture and recycle everything you can, and lobby hard for the rest of it.

Which do you think is better? Weigh in here. is dedicated to our users. We focus our attention on changing the world through recycling, waste-to-energy and conservation. We reward our users for their sustainable behavior on our website, through our Greenopolis recycling kiosks and with curbside recycling programs.


Keywords: Greenopolis | Plastic | Resources | glass | pet | recycle | reuse