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, and it's steel.

Glass containers

Glass is a good choice. We're not going to pretend it isn't — see below. But look at the lid.

Almost every glass container in a Dutch kitchen closes with a plastic lid. IKEA, Mepal, HEMA, Glasslock, Pyrex: the box is glass, the lid is polypropylene or an unnamed "BPA-free plastic."

There is an exception, and it deserves a straight mention. Safecourt Kitchen, a Dutch brand, sells borosilicate glass containers with a glass lid and a silicone ring. In their own words: "je eten raakt alleen glas en siliconen. Geen plastic deksels, geen coatings." That is the same idea as ours: two materials, both named. If you want glass and no plastic lid, it exists, and we'd rather you heard it here.

So between a glass lid and a steel one, the difference isn't what touches your food. It's what happens when it hits the floor.

Borosilicate is good glass. It's made for heat: it goes from cold to hot without cracking, and that's what it's for. It isn't made for falling. Drop it on tiles, on a wooden floor, on almost any hard floor, and it breaks, in large, sharp pieces. With a glass lid, the box and the lid can both break. In the kitchen that's a risk you can manage. In a school bag, a gym bag or on the back of a bike, it's the job steel is built for: drop it and you get a dent, not shards.

And once it's broken, it doesn't go in the glasbak. Heat-resistant glass melts at a higher temperature than bottles and jars and disrupts glass recycling, so it belongs in general waste. With a glass lid, that goes for the lid too. Steel goes with scrap metal; the seal comes out and goes in general waste. (Source: waarzitwatin.nl)

Glass is for the microwave. Steel is for everything else.

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.

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. (The oven isn't the difference: our containers can go in the oven too, as long as the lid and the seal come off.)

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 so.)
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; the glass section was re-checked in September 2026. All subject to change by the manufacturer. Our own bottle construction was confirmed with our supplier in July 2026.