PET, glass or can: the question that actually decides it

Glass feels like the responsible choice. In every comparison we were able to open, single-use glass is the worst one on the shelf.

That is not a defence of plastic. It is what happens when you stop asking which material sounds better and start measuring what each one costs to make and to move.

But the material comparison is not the decision, and this is the part most packaging arguments never reach. In the United Kingdom, a rule taking effect on 1 October 2027 quietly settles a large part of the question for you. We worked through both halves before choosing our first format, so here is the reasoning, and here is the number we could not verify.

Where the intuition comes from

Glass is inert. It does not leach, it carries no plastic association, and it has been in service for centuries. It photographs beautifully, which influences brand decisions more than anyone admits. Pour water from a glass bottle at a table and the occasion reads differently.

None of that is wrong. It is simply not what a lifecycle assessment measures.

What the measurements say

Glass is heavy and it is made hot. Furnace temperatures are expensive in energy whether the feedstock is virgin sand or recycled cullet, and then that weight is carried on a lorry, and carried again.

The International Aluminium comparison of single-use containers puts it plainly. For carbonated drinks overall, aluminium and PET sit within the same range as each other, while single-use glass has a significantly higher carbon footprint. PET containers, in its words, have far lower carbon footprints than single-use glass.

Two specific figures from that work are worth holding on to. A 12oz glass bottle carries more than six times the footprint of a 16oz aluminium can, and note the direction of the sizes there: the glass is the smaller container. In the Brazilian studies, a 60cl glass bottle came out at over ten times an aluminium can.

The rule that takes the decision out of your hands

Here is where the argument turns.

From 1 October 2027 every part of the United Kingdom operates a deposit return scheme. The deposit is 20p on all in-scope containers. England, Northern Ireland and Scotland cover single-use drinks containers between 150 millilitres and three litres made from PET plastic, steel and aluminium.

Not glass.

The reasoning is the part worth reading twice. According to the House of Commons Library briefing, the UK Government decided against including glass because of concerns about safety, storage and recycling quality. Those are operational objections. Carbon was not the argument.

So the format with the highest single-use footprint is also the one excluded from the mechanism designed to bring containers back, and it was excluded for reasons that have nothing to do with its footprint. A brand choosing single-use glass in the UK for environmental reasons is choosing the worst-measuring format in the part of the market least equipped to recover it.

Wales included glass, and "included" is doing a lot of work

Wales starts on the same date and does include glass bottles. It is also introducing them initially without a deposit, specifically to avoid immediate changes to labelling and distribution. Wales plans a reuse scheme as part of its arrangement but has not yet made full legislative provision for it.

A container in scope but carrying no deposit is in the scheme on paper. The 20p is the entire behavioural mechanism, and without it the listing is administrative.

What we could not check

The literature most often cited in favour of refillable glass sits behind publisher paywalls that blocked us, including in a real browser. We are not going to quote figures from papers we could not open.

So state the limit honestly. Refillable systems genuinely change this comparison, because a glass bottle collected, washed and refilled many times spreads that furnace across many uses rather than one. The direction of that effect is not in dispute. The size of it is a number we have not personally verified, and an unverified number is worse than no number.

If you are making this decision with real money, obtain those studies properly rather than relying on anyone's summary of them, including ours.

What we chose, and what we are not claiming

Our first product is a 500 ml still water in food-grade PET with a black tamper-evident cap. It sits inside the scheme's size range and inside its material scope, so from October 2027 it carries a deposit and has a route back that does not depend on a household bin.

If a glass bottle or a can ever joins the range, the reasoning above is the test it will have to survive.

What we say about recyclability is one sentence and it does not grow: the bottle body is recyclable, and the cap and the two labels are separate materials that are not covered by that. We do not say eco-friendly, sustainable, or a hundred per cent recycled bottle.

There is also a matter of timing. The scheme starts in October 2027, and deposit return brings labelling obligations with it. Gazian's packaging is specified with those obligations designed in, not retrofitted, which is the cheap side of that problem to be on.

The comparison, without the adjectives

Format	Single-use footprint	In the UK scheme from 1 Oct 2027
Glass	Significantly higher than the other two	Excluded in England, NI and Scotland. In scope in Wales, initially with no deposit
PET	Far lower than single-use glass	Included, 150 ml to 3 L, 20p
Aluminium	Same range as PET	Included, 150 ml to 3 L, 20p

The practical question for anyone choosing a first format is not which material is greener in the abstract. It is whether your container has a way home. In the UK from next October that is answered for you, and the answer is not the one the aesthetics would have picked.