What touches your food

Every container has a lid. Almost nobody tells you what it's made of. Here is the whole category, in one table, including us.

We're not going to tell you plastic is dangerous. Nobody can tell you that honestly, and the brands that pretend otherwise are selling you fear at a markup.

We're going to tell you something much simpler, and much easier to check: your food doesn't only touch the box. It touches the lid. And in this category, the lid is where the plastic went.

Steel containers and bottles

The word "steel" is doing a lot of work

There's one thing a table like this can't show you, because the grade matters as much as the material.

"Stainless steel" is not one thing. 304 is the food-grade standard. The cheaper 200-series alloys — 201, 202 — are also sold as food-safe steel, and they are common in this category, sometimes on the surface the food actually sits on. Almost nobody prints the number on the label. If a product just says "stainless steel," that is the answer you're getting.

We're not going to name and shame anyone for that, because — as you're about to read — we use 201 ourselves.

So, ours. Every surface that touches your food or water — in every product we sell — is 304. But our bottle is double-walled, and the outer skin of that bottle, and of its cap, is 201 stainless steel. Nothing touches it. It's the part your hand holds.

We could have left that out. Nobody asked, no competitor publishes their outer-wall grade, and it makes no difference to what you drink. But this is the page where we tell you what things are made of, and "we only disclose the flattering parts" is not a policy. So: 304 everywhere it counts. 201 on the outside of the bottle. One food-grade silicone seal. That's the list.

A word about Dopper

Dopper is the most trusted bottle brand in the Netherlands, and they deserve more than one row in a table.

They are a B Corp. Their steel is 90% recycled. They fund drinking-water projects. And their villain has always been the plastic soup — single-use versus reusable. On that argument they have been right for fifteen years, and they have done more for it than we ever will.

They are also unusually open about their materials. Their help centre lists every component of every product, which is more than almost anyone in this category manages. We didn't have to dig for any of this. We just read their page.

Here is what it says:

• Dopper Original — "CirculenRenew - PP (bottle and cap)." It's a plastic bottle. They know, and they've published a blog post explaining exactly why.
• Dopper Insulated — "18/8 Stainless Steel (bottle)… Polypropylene (cap)."
• Dopper Steel (350 / 490 ml) — "PP - Polypropylene (cap)."
• Dopper Steel (800 ml / 1.1 L) — "18/8 Stainless Steel (bottle and cap)" and then, on the very next line, "Polypropylene (cap)." Both.
• Dopper Glass — "PP - Polypropylene (cap)."
• And the cup you drink from — on every single model — is Copolyester.

That steel entry is not a lie, and we're not calling it one. It is a company honest enough to publish its full materials list, which still cannot tell you in one clear line what your water touches. That isn't Dopper's failing. That's the category.

Dopper set out to answer a different question — how do we stop people buying single-use bottles? — and answered it extremely well. They never claimed to answer this one.

And here's where we lose to them. The Dopper Insulated is vacuum-insulated. Ours is double-walled, but the gap is air, not a vacuum — which is a real difference, not a technicality. Theirs will hold your water cold for far longer than ours. If that's what you need, buy theirs; it's the better product for that job. Their 18/8 steel is also the same grade as ours: 18/8 and 304 are two names for the same alloy. We have no advantage there and we're not going to invent one.

What we have is a cap. €19.95, and it's steel.

Glass containers

Glass is a good choice. We're not going to pretend it isn't — see below. But there's one thing about it that almost nobody has looked at.

We checked fifteen glass brands. Every glass container sold in the Netherlands that is designed to be carried and sealed has a plastic lid. Not most. All of them.

The only genuinely all-glass lids in the category belong to canning jars — and their own makers tell you not to use them for daily storage.

And Pyrex proves the gap by failing to fill it: they built a glass-lid range, and dropped the leakproof claim. In this category you can have leakproof, or you can have no plastic. Until now, nobody offered both.

Glass solved the box and forgot the lid. A glass container is a plastic-lidded container with a transparent bottom.

Now the honest part: where we lose

A page like this is worthless if it only lists other people's problems. So here are ours.

There is silicone in our products

One food-grade silicone seal, so it doesn't leak. It is not steel, and we're not going to hide it in a footnote — it's the second of the only two materials we use, and we name it on every product page. It also isn't steel, and you're entitled to know it's there.

It also wears out. So we sell you a new one. For a few euros, for as long as you own the product.

Our bottle's outer shell is 201 steel, not 304

The bottle is double-walled. The inner wall — the only surface your water ever touches — is 304 food-grade stainless steel, and so is the inside of the cap. The outer skin, the part your hand holds, is 201.

201 is a stainless steel with less nickel and more manganese. It is perfectly normal for the outside of a bottle, it touches nothing you drink, and it makes no difference whatsoever to your water. It is also, straightforwardly, a lower grade than 304 — less resistant to corrosion.

We're telling you because this is the page that says grade matters. Making that point and then quietly leaving our own number off it would make everything else here worthless. The distinction we'd draw is real — ours is the outside of a bottle, not a surface food sits on — but you get to judge that, not us.

And our guarantee covers it. Ten years, on every steel part, 201 included. If it rusts through, we replace it. We're not going to name a grade and then exclude it from the promise. The guarantee →

Our bottle is double-walled, but it isn't a vacuum flask

The gap between the walls is air, not a vacuum. In practice: it won't sweat on your desk, and cold water stays cold longer than it would in a single-wall bottle. It will not keep your water cold for nine hours, and it will not hold coffee hot all day.

The Dopper Insulated, Chilly's and Hydro Flask are true vacuum flasks. For temperature, they beat us, and we're not going to pretend otherwise. We're not going to publish an hours figure either — we haven't tested one, and a number we can't stand behind is exactly the sort of thing this page exists to expose.

Steel doesn't go in the microwave

Glass does. This is a real, daily advantage and we can't argue with it. The Voedingscentrum recommends glass over steel for exactly this reason, and they're right to.

You can't see inside

Glass wins this outright. Unanswerable.

Glass is cheaper

An IKEA 365+ 1L glass box is €4.49. We will never compete with that, and we're not going to try.

Steel releases trace nickel and chromium

This is real and it's findable, so we'd rather you heard it here.

The research people cite (Kamerud et al., 2013) simmered tomato sauce at 85°C for six to twenty hours. It's a study about cookware, not storage. Nobody simmers sauce in a lunchbox, and migration drops sharply after the first few uses.

We are not going to tell you "steel doesn't leach" — no study exists of cold-storage migration from 304, so nobody can honestly prove that negative. What we'll tell you instead is that roughly 10–15% of people are nickel-sensitive, and if that's you, you should know that before you buy from us.

It's heavier

About 1.5× the weight of plastic. Not double — we've seen brands claim glass is "twice as heavy" and it isn't. But heavier, yes.

So what's the actual argument

Not that plastic is poisoning you. Nobody can say that honestly.

Just this:

1. Plastic doesn't belong in food. (The Voedingscentrum says this word for word.)
2. Nobody knows the long-term effects yet. (Every Dutch authority says this.)
3. So why keep the question open, when a material exists that closes it?

Two materials. Both named. Stainless steel and one food-grade silicone seal — and every surface your food or water touches is 304. That's the entire list, across everything we sell, lids and bottle caps included. If a third material ever appears, it goes on the page before it goes in the box. That is not a slogan. It is the reason this page exists, and it is why the paragraph about our own 201 is on it.

Replace the plastic →

Food should be stored without doubt.

Every quotation on this page is taken from the brand's own published product page, FAQ or materials listing. Prices and specifications current as of July 2026 and subject to change by the manufacturer. Our own bottle construction was confirmed with our supplier in July 2026.