Kitchenware materials: 136 products, and why the expensive ones are made of worse stuff

Between August and September 2026 we read every product page, FAQ, care instruction, published certificate and statutory filing we could find for 136 kitchenware products across 5 categories, and worked out what each one is actually made of. Then we scored them on a fixed 100-point materials rubric: what the food touches (60 points), the lids, seals and handles (25), and whether anyone other than the manufacturer has confirmed it (15).

Not on whether the product is safe — we have no laboratory and will not pretend to. On what it is made from, which is a knowable fact with known properties, and which turns out to have almost nothing to do with what it costs.

The finding: paying more gets you worse materials

Across the 105 products with a listed price, the correlation between price and materials score is r = -0.22. It is a weak-to-moderate relationship and it is negative, which is the opposite of what almost every buying guide in this category implies. It is not strong enough to predict any individual product, and it is more than strong enough to say that paying more does not buy you better materials.

• The cheapest item on the table, the Mainstays Food Storage Bento Container 42oz at $4.34, scores 33/100 — “BPA-free material” — the resin is never named · silicone seal ring named.
• The most expensive, the Dreo ChefMaker Combi Fryer 6 qt at $359, scores 32/100 — Sold with a “transparent glass basket”. The only replacement Dreo sells for it is the “Extra ChefMaker Non-stick Basket” with a “clear viewing window”. Coating never named.
• The cheaper half of the table averages 61.9. The dearer half averages 51.5.

The mechanism is not mysterious once you look at it. What money buys in this category is coatings, non-stick performance, design and electronics — and every one of those puts something between your food and an inert surface. A bare steel bottle has nothing applied to it. A premium air fryer has a coated basket, and the coating is the product.

The correlation was stronger on our first, smaller sample — r = −0.44 across 18 priced products in September 2026. It weakened as the table grew, which is what usually happens to a correlation when the sample gets bigger, and we would rather show that than quietly keep the better number.

What these products are actually made of

• 61 of 136 (45%) have an inert, uncoated food-contact surface — bare stainless, cast iron, glass or solid ceramic.
• Of those, 35 name the material precisely enough to check: a steel grade, a glass chemistry, or one material all the way through.
• 64 of 136 (47%) have something applied between the food and the base material.
• 13 of 136 (10%) disclose a fluoropolymer coating outright. Most of them do it in a California AB 1200 filing rather than on the product page — which is to say, because a statute compels it.
• 14 of 136 (10%) have a coating whose chemistry is never named anywhere: Our Place Always Pan (ceramic), Our Place Wonder Oven, PackIt Freezable Lunch Box, Chefman TurboFry Touch “Stainless-Steel” 8 qt, Instant Vortex 9 qt VersaZone, Hamilton Beach 5.8 qt Digital Air Fryer, Thyme & Table Supreme 12-Piece Cookware Set, The Pioneer Woman Prairie Signature Fry Pan 8in, Mainstays 13-Piece Nonstick Aluminium Cookware Set, Mainstays 7-Piece Nonstick Aluminium Cookware Set, Thyme & Table Hard Anodized 15-Piece Set, Beautiful 6 Qt Air Fryer, TurboCrisp (Sage Green), Ninja Crispi 5-in-1 Glass Air Fry System (Costco), Ninja Foodi 6-in-1 10-qt DualZone Air Fryer (Costco). A trade name is not a material.

The lid problem

10 of 136 (7%) contain no plastic at all: Lodge Classic Cast Iron Skillet, ECOlunchbox Three-in-One Giant, Stasher Gallon Bag, Elephant Box 2L Stainless, LunchBots Small Snack Packer, Stasher Reusable Sandwich Bag, Smithey Ironware No. 12 Skillet, Matfer Bourgeat Black Carbon Steel 10.25", Pura Sport Mini 11 oz, Kirkland Signature 12-Piece Non-Stick Cookware Set. At the other end, 40 products put an unnamed plastic in direct food or mouth contact — Pyrex Simply Store, Hydro Flask Kids 12 oz Bottle, Stanley Quencher H2.0 FlowState 40 oz, Purist Mover 18 oz, Brita Premium Filtering Bottle 32 oz, Ello Syndicate 20 oz Glass, Takeya Actives 18 oz, Iron Flask 40 oz Wide Mouth, Nalgene 32 oz Wide Mouth Sustain, Contigo Kids Straw Bottle 14 oz, Rubbermaid Brilliance Glass 10pc Set, OXO Good Grips POP Container 2.8 qt, WeeSprout Stainless Bento, Large, Hydro Flask 12 oz Kids Food Jar, Thermos FUNtainer 10 oz Food Jar, monbento MB Tresor Kids Bento, Simple Modern Porter Bento Box, FINEX 12" Cast Iron Skillet, Hydro Flask 32 oz Wide Mouth, Duralex Freshbox Square Set, De’Longhi IdealFry Rapid Crisp 4 qt, Thyme & Table Granite 12-Piece Cookware Set, Beautiful 12-Piece Ceramic Set, Black Sesame, Circulon Premier Professional 10-Piece (Costco), Circulon A1 ScratchDefense 12-Piece (Costco), Mainstays 13-Piece Nonstick Aluminium Cookware Set, Mainstays 7-Piece Nonstick Aluminium Cookware Set, Thyme & Table Hard Anodized 15-Piece Set, Beautiful 6 Qt Air Fryer, EverGood Ceramic (Lavender), Beautiful 6 Qt Air Fryer, TurboCrisp (Sage Green), Beautiful 6 Qt Air Fryer, TurboCrisp (Black Sesame), Ninja Crispi 5-in-1 Glass Air Fry System (Costco), Ninja Foodi 6-in-1 10-qt DualZone Air Fryer (Costco), Snapware Pyrex 18-Piece Glass Storage Set (Costco), Mainstays Kids 4-Compartment Bento Box, Ozark Trail 40oz Insulated Stainless Bottle, Ozark Trail 32oz Insulated Flip-Straw Bottle, Ozark Trail 1.1-Liter Insulated Stainless Bottle, Owala SmoothSip Slider 20oz 2-Pack (Costco), Contigo Autoseal Couture 20oz 2-Pack (Costco) — which is how a glass storage container and a steel bottle end up scoring like coated goods.

This is the part buyers most often miss. “Glass food storage” is glass and a lid, and the lid is the part that touches hot food when you take the box out of the microwave.

Almost nobody has anything confirming it

• 1 of 136 (1%) publishes dated certificates from a named laboratory — Xtrema Classic Skillet.
• 83 of 136 (61%) publish nothing at all beyond their own description of the materials.

This is only 15 points of the 100 on purpose. A bare cast iron skillet is bare cast iron whether or not anyone certifies it. But it is why an unnamed material cannot score well: you cannot call something inert if nobody will tell you what it is.

By category

Air fryers are the worst category by a wide margin, and for a structural reason: the whole appliance exists to crisp food against a non-stick surface, so the coating is not an optional extra, it is the function. The one exception on our table uses a glass bowl instead. The full category is here.

Lunch boxes are the best, for the mirror-image reason: a steel box has nothing to coat. The gap between the best and worst category is not about how careful the brands are. It is about whether the product needs a coating to work.

How the scoring works

Sixty points for the surface your food touches, on a fixed ladder from “one inert material, fully specified, nothing applied” down to “no material stated anywhere”. Twenty-five for everything else in the product — lids, seals, handles, the outside. Fifteen for whether the materials claim is backed by a named laboratory, a statutory filing, or nothing.

Because the parts are weighted unevenly and the rungs sit where the material distinctions actually fall, scores do not land on round numbers. The rubric is published in full and applied mechanically. It is here, with the reasoning for every judgement call. Where a manufacturer does not publish something we record UNVERIFIED rather than guessing.

Related

• Which brands actually publish what’s in their products
• The full scored table, 136 products, every claim sourced
• The rubric