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

Milo by Nestle

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:

Milo refill pack

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?

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    the energy necessary to recycle a tin can is much higher than anything plastic related, so its carbon footprint would be much higher. Making it for the first time also requires much more resource and therefore generates more pollution. Plastic is surprisingly cheap for resource and energy (more than paper even), but is usually not recycled. I don't have the exact numbers, but provided you properly throw the plastic, chances are refill would be much better. Story would be different if the company recovered and reused the tins cans. Apr 18, 2020 at 7:11
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    Will the choice matter compared to the impact of what's inside the container? Jun 29, 2020 at 17:44
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    @Jean-PaulCalderone Milo's cocoa is (allegedly) sustainably grown and certified by UTZ. Nestle has done some real dodgy things in the past though, so who knows. But for the purposes of this question, yeah I'm mainly concerned about the packaging side of things.
    – Robotnik
    Jun 29, 2020 at 22:23

4 Answers 4


In cases like this we do what is called an LCA.

This looks at a few areas, production Transportation as well as end of life.

While I do not have an exact case study for this application, I have one which is worse case situation for plastics.

100% aluminium vs tin plate which are what milo cans are made off And bottles rigids for plastics vs flexibles in your question.

100% Al would be easier to recycle than tin plate and a lot lighter. Rigid bottles use alot more plastics as compared with flexible films.



Plastics are better.


This is an LCA of a pouch vs a can for pasta sauce.

Results: Likewise plastic better.

Honestly in terms of matrix it’s harder to find a LCA which states that metal is better than plastics environmentally.

But there are use cases where metal and glass are better, and this is with regards to extended shelf life,if you’re planning on keeping a drink around for 5-6 years your better off using glass or metal due to the barrier properties. But that’s a different discussion.


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.

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    This doesn't quite answer my question. Yes, tins are better than plastic, but if I want more chocolate powder, should I refill my tin by purchasing plastic-packaged refills, or buy new tins every time?
    – Robotnik
    May 5, 2020 at 23:36
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    Tins are only better than plastic if you have a use case for them, i.e. if they are used "as is" over and over again to store stuff. If you use them only once, they're pretty terrible... Jun 26, 2020 at 7:29

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.


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?

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    Please provide your sources.
    – LShaver
    Jul 26, 2021 at 3:41

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