Should I purchase new tins or plastic refills for chocolate powder?

Question

A few brands of chocolate milk mix come in re-sealable tins like this:

It is also possible (and slightly cheaper) to buy 'refill packs', in order to reuse the tin. However, these refill packs are made of a soft plastic packaging:

I have read that it is easier/more efficient to recycle tins vs soft plastics, and that the recycling rates are also higher for the former. Does this mean - purely from a sustainability standpoint - I should buy new tins over refill packs?

How do the lifecycles of both tins and refill packs compare?

Answer 1

Tins ultimately are more sustainable than any soft plastic packaging not only from a recycling point of view but even otherwise. They can be reused safely and for longer periods of time. In fact the only time you will need to throw away a tin is when it is accidentally crushed beyond a certain point where it cannot be restored to the previous shape and that too is just a point of aesthetics unless of course there are holes in your tin which is the only case which can be justified as a practical reason to throw them away and if you will, that too can be solved by applying a small amount of tin metal on the hole to cover it up.

Answer 2

One thing is clear at least.

Firstly, it doesn't matter how sustainable the packaging it. It matters far more how sustainable the contents of the package are.

For example for a plastic refill package, I find it very hard to believe the plastic would weigh more than 10 grams. 10 grams of plastic correspond to 20-30 grams of CO₂ emissions.

If there's half a kilogram of chocolate powder there, it also creates about 2-3 g/g of CO₂ emissions. But because half a kilogram is so much more than 10 grams, the ecological footprint of the contents is about 50 times more than the ecological footprint of the packaging.

The metal packaging probably weighs far more than the plastic packaging: I estimate it's not 10 grams but 100 grams. Steelmaking has emissions of 1-2 g/g, so the steel packaging would create 100-200 grams of CO₂ emissions. That's about six times more than for the plastic packaging, but steel recycling is easier than for plastic, so by recycling you can reduce the emissions. I suspect if the steel is recycled enough many times, that the metal packaging would win over the plastic packaging. I'm not sure about this though: winning would need that recycled steel production causes 16.66% or less of the emissions that producing steel from iron ore causes. I failed to find a source for the emissions of recycled steel.

However, for average recycling rates plastic would win. Wikipedia says only 65% of cans are recycled.

Answer 3

It matters little, While it takes more energy to make a tin than a bag, HOW much cocoa mix are you buying to justify. It takes 6 megajoules to make an aluminum can, Tin with a lower melting point, slightly less. It takes less than half a megajoule of energy to make a plastic bag.

On the other hand, buy cocoa powder in reusable container that sells it by weight?