If you searched for a plastic-free food container, you are about to read something slightly annoying.
We sell steel food containers, and we are not going to tell you they are plastic-free.
Not because they are full of plastic. They aren’t — no plastic touches your food in anything we make, and the lid and the bottle cap are steel, which is more than almost anyone in this category can say.
We won’t say it because the phrase does not mean what you think it means, and because the moment we used it, we would be doing the exact thing this company exists to object to.
Let us show you what we mean.
“Plastic-free” has no legal definition
There is no standard behind it. No certifying body, no threshold, no regulator checking. Unlike “organic” or “food grade” — which are at least contested — “plastic-free” is simply a phrase a brand decides to print.
Which means every company using it gets to define it privately, and none of them will show you the definition.
In practice, it usually means one of these three things:
- “The part you look at isn’t plastic.” The body is steel or glass. The lid is polypropylene.
- “The plastic isn’t touching the food.” There is plastic in the clips, the hinge, the outer shell, the straw.
- “We don’t count silicone.” Which — fairly — most people don’t. More on that below, because it applies to us too.
Look at what gets sold under the phrase
These are not obscure brands. These are the ones that come up when you search the exact thing you just searched for. Every quotation is from their own website.
Klean Kanteen — probably the most credible plastic-free name in the category — ships polypropylene caps as standard. The cap that isn’t plastic is a paid upgrade. You can buy a plastic-free bottle from them. It costs extra.
Hydro Flask, in their own FAQ: “All of Hydro Flask’s caps are made out of BPA/BPS free polypropylene.” Note the construction — BPA-free doing the reassuring, while polypropylene sits quietly at the end of the sentence.
Every glass container sold in the Netherlands. We checked fifteen brands. Pyrex, Glasslock, IKEA, HEMA, Duralex, Mepal, OXO. All of them close with a plastic lid. IKEA at least says so plainly: “Lid: Polypropylene plastic.” Most won’t even name the polymer. The full list is here.
ECOlunchbox — a genuinely plastic-free-positioned brand — discloses in its own FAQ that most of its bentos are made from stainless steel 201, not 304. That is a different issue, but it makes the same point: the marketing phrase and the material specification are two separate documents.
None of these companies is lying. Each of them has a private definition under which their claim is true.
That is precisely the problem. A claim that is true under a definition you cannot see is not a claim. It is a mood.
Now our turn
Here is what is in a Stainless Co. container.
304 food-grade stainless steel. The body. The lid. The divider. The bottle cap.
One food-grade silicone seal. So it doesn’t leak.
That is the whole list. There is no third thing.
And that silicone seal is exactly why we will not print “plastic-free” on the box.
“But silicone isn’t plastic”
Correct — and we could hide behind that, which is the temptation.
Silicone is a synthetic polymer, but it is built on a silicon–oxygen backbone rather than the carbon chains that define plastics. It behaves differently: it doesn’t soften and warp with heat the way polypropylene does, it doesn’t rely on plasticisers to stay flexible, and it is inert across a much wider temperature range. Regulators, chemists and most people treat it as its own category. Every serious “plastic-free” brand in this industry uses silicone somewhere and does not count it.
So we could say “plastic-free” and defend it. It would probably survive a fact-check.
We are not going to, and here is the actual reason.
Every claim in this category is technically defensible under a definition the brand keeps to itself. “BPA-free” was technically defensible — right up to the point where the substitute turned out to be another bisphenol. “Microwave-safe” is technically defensible — it just never meant what you thought it meant.
We are not interested in owning one more phrase that requires a footnote. The footnote is the whole disease.
What we say instead
Not what is absent. What is present.
Two materials. Both named.
304 stainless steel, and one food-grade silicone seal. That is the entire list — across everything we sell, lids and bottle caps included. If a third ever appears, it goes on the page before it goes in the box.
We say two, out loud, because nobody in this category would ever volunteer a number greater than one. They all round down. We would rather you counted.
And the seal is not a weakness we are managing. It is the proof of the rule. A company willing to name its one non-steel part is a company you can believe about the other ninety-nine percent.
It also eventually wears out — silicone loses its spring after a few years of dishwasher cycles — so we sell you a new one for a few euros, for as long as you own the product. Glasslock, for the record, “the gaskets are not available as a separate replacement part.”
The one sentence we will use
No plastic touches your food.
That is narrower than “plastic-free,” and it is completely true, and you can verify it in about ten seconds by looking at the lid.
So how do you actually find one?
If you are shopping for this, three questions will tell you more than any badge on the packaging.
- What is the lid made of? Not the body — the lid. It is the surface your food is pressed against for three days, and it is where the plastic almost always is. If the page won’t say, that is the answer.
- What grade is the steel? 201, 202, 304 and 316 are all sold as “food grade,” and they are not the same material. Here is why that matters.
- Can you buy a replacement seal? If not, the container has an expiry date the brand hasn’t mentioned.
Ask those three of anyone. Including us.
See the whole category answer them →
Food should be stored without doubt.
Every brand quotation on this page is taken from that company’s own published product page or FAQ, current as of July 2026.