why is burning plastics (like polyethylene) bad when it’s a hydrocarbon like wood?


Burning plastics is bad. We’ve all been told this. And, I can see why burning PVC with its chlorine in there could be an issue. What about polyethylene and other plastics made out of just hydrogen and carbon?

In: Chemistry

Mostly because it’s made from a non-renewable source. Wood can grow back. Oil cannot.

Also a lot of plastics contain other stuff that when burnt can produce poisonous fumes like cyanates etc.

There are very hazardous substances out there which are “just hydrogen and carbon”. One group of these are called “dioxins”, which are produced in high quantities when plastics are burned and are highly toxic.

There is also the fact that plastics don’t always totally combust, and small particles of unburned plastic entering the environment (or your body) can be dangerous. Since plastics aren’t easily processed biologically this contamination is more hazardous than, for example, wood ash.

Also, as a final note, burning wood isn’t exactly great for you. It may produce fewer toxic pollutants but it still produces a significant amount.

The fumes are patently carcinogenic, leave plastic on everything the smoke touches, and are a rainbow of greenhouse gasses.

Depending on your flavor of plastic, the fumes may be straight up poison too.

Also, when you burn it, the material is no longer recyclable, and will just be unusable toxic shit for all time.

Plastic is a hydrocarbon. It’s a good hydrocarbon chain, but not web. Chains are cool but to make plastic containers you need to find some processes to bond up all the chains together and make it a hard and cohesive structure. To go from chains of relatively chill looking carbon-based molecules to sheets of plastic you can make Tupperware out of and microwave, a lot of chemistry has to go down. And a lot of the chemicals used to bind and bond and harden (like the infamous BPA aka Bisphenol A) have some inevitable continued presence in the finished product. Plastic isn’t just plastic, it’s plastic and some residues of the chemicals needed to get it to be just right as a material to work with. So when you burn plastic, you’re basically having a reaction with all those residual chemicals and that shit nasty.

Carbon, Oxygen: Not bad for you.

Carbon Dioxide: Not bad for you except at high concentration.

Carbon Monoxide: Kills you

Being made of the same elements doesn’t mean a compound behaves the same.