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> Ceramics and plastics are the worst (this includes any non-sticking coatings), because, unlike for metals and glasses, their chemical composition is usually k

> Ceramics and plastics are the worst (this includes any non-sticking coatings), because, unlike for metals and glasses, their chemical composition is usually kept secret by their manufactures, so you never know what they may leach. Again, when you refer to ceramics, are you referring to the tons of ceramic coated cookware that is now immensely popular as a replacement for Teflon? Is this stuff just as bad? https://www.goodhousekeeping.com/cooking-tools/a26078798/best-ceramic-cookware/ https://www.goodhousekeeping.com/cooking-tools/a26078798/bes...

adrian_b 5y ago
It is not clear from the advertisements of the vendors what kind of material is used for the so-called "ceramic" coatings. I believe that they use the word "ceramic" to say that the coating is not made from an organic polymer, like Teflon, but from an inorganic oxide or mixture of inorganic oxides. The correct meaning of ceramic is a material that before processing is soft and plastic, so you can give it any form you want. Then, after heating at very high temperature in an oven, a.k.a. burning, the finished ceramic product becomes hard. I am pretty certain that this is not how the so-called ceramic coatings are made. The cookware that I have seen with "ceramic" coatings had bodies made of aluminum. So I assume that the "ceramic" coatings are mostly of aluminum oxide, probably grown electrolytically or chemically. True ceramic products consisting mainly of aluminum oxide are very common, so I assume that this is why the "ceramic" coating vendors use the word "ceramic". Alumina, a.k.a. aluminum oxide, is inert enough in most conditions to be safe for food contact, even if not as safe in contact with acidic juices as glass. As always, the base material is less concerning than the possible existence of undisclosed additives. It is possible that the so-called "ceramic" coatings are perfectly safe, but nevertheless I would not buy one unless the vendor would state clearly the composition of their "ceramic". I have seen too many contrary examples in the past, so that I cannot trust anyone who says "Trust us, it is good for you", without providing additional relevant information.
- clsec 5y ago
  I believe the process that you're describing is called powder coating [1]. [1] https://en.wikipedia.org/wiki/Powder_coating https://en.wikipedia.org/wiki/Powder_coating
  - 83 5y ago
    The process to grow aluminum oxide on aluminum is called anodizing. Powder coating is almost entirely relegated to plastic coating afaik.
    - clsec 5y ago
      You are correct, I misread OP's post.

adrian_b 5y ago

It is not clear from the advertisements of the vendors what kind of material is used for the so-called "ceramic" coatings. I believe that they use the word "ceramic" to say that the coating is not made from an organic polymer, like Teflon, but from an inorganic oxide or mixture of inorganic oxides. The correct meaning of ceramic is a material that before processing is soft and plastic, so you can give it any form you want. Then, after heating at very high temperature in an oven, a.k.a. burning, the finished ceramic product becomes hard. I am pretty certain that this is not how the so-called ceramic coatings are made. The cookware that I have seen with "ceramic" coatings had bodies made of aluminum. So I assume that the "ceramic" coatings are mostly of aluminum oxide, probably grown electrolytically or chemically. True ceramic products consisting mainly of aluminum oxide are very common, so I assume that this is why the "ceramic" coating vendors use the word "ceramic". Alumina, a.k.a. aluminum oxide, is inert enough in most conditions to be safe for food contact, even if not as safe in contact with acidic juices as glass. As always, the base material is less concerning than the possible existence of undisclosed additives. It is possible that the so-called "ceramic" coatings are perfectly safe, but nevertheless I would not buy one unless the vendor would state clearly the composition of their "ceramic". I have seen too many contrary examples in the past, so that I cannot trust anyone who says "Trust us, it is good for you", without providing additional relevant information.

clsec 5y ago
I believe the process that you're describing is called powder coating [1]. [1] https://en.wikipedia.org/wiki/Powder_coating https://en.wikipedia.org/wiki/Powder_coating
- 83 5y ago
  The process to grow aluminum oxide on aluminum is called anodizing. Powder coating is almost entirely relegated to plastic coating afaik.
  - clsec 5y ago
    You are correct, I misread OP's post.