News for hackers. Stuff that matters.
Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @04:23AM (#30624950)
It should be kept in mind that almost any material used in contact with food will leach something, especially when it is used during cooking, i.e. at high temperatures, and, in the case of metals, when the food contains fruit juices or vegetable juices, which are acidic.

So what matters is the hierarchy of the materials from this point of view, i.e. which are better and which are worse.

The best material for food-contact is glass, but glass, while perfect for storage, is not suitable for most types of cooking (even if it is quite possible for someone to eat only food cooked in a microwave oven, in glass cookware).

The next best material is titanium (commercially pure titanium, not the frequently encountered Ti-Al-V alloy). Titanium cookware exists, but it is normally too expensive, unless it is used in some activities where its low weight can justify the high price.

After these 2 cookware materials, which unfortunately are not an acceptable choice for most people, comes the stainless steel.

Yes, stainless steel will leach a little nickel and chromium. However this leaching will be large only for new cookware and it diminishes a lot for used cookware. Even in the case of people with nickel sensitivity, most of which are women, the quantities of nickel leached from used stainless steel cookware are far too low to have any effect.

All the other materials that are used for cookware, including ceramics, can be sources of much more dangerous leaching than stainless steel (excluding glass & titanium).

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.

Re:Stainless steel leaches nickel and chromium into foods du... by samatman on Thursday March 10, 2022 @07:43AM (#30626255)
The distinction you're trying to draw between glass and ceramics doesn't exist, ceramics are generally glazed, which means "covered in a coating of glass".

Enameled pans aren't going to leach anything if you buy them from any reputable manufacturer (which is at least all of the European, American, and Japanese ones) because any colorants added to the glaze will be rated as food safe. In fact, you mentioned titanium: that's what's used to make the inside of white enameled pots look white.

Enameled cast iron (or enameled anything) is a fine choice, it comes with its own limitations culinarily (and advantages) but it isn't going leach anything into your food.

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @08:34AM (#30626693)
You are right that glaze is a kind of glass.

Nevertheless, most glazes have a much more complex composition than the standard borosilicate or soda-lime glasses.

Glazes usually contain colorants and various additives that improve certain properties useful during manufacturing, which do not exist in the glasses used for vessels.

It is possible to make glazes that are perfectly safe for food contact, but historically there were many examples of glazes with harmful components.

Unless a manufacturer provides the composition of the glaze used by them, you cannot know how safe it is.

Moreover, glazes and enamels have a problem that does not exist for stainless steel vessels. The glazes or enamels may crack and expose the base material to the food. However that is somewhat mitigated by their lower price, which facilitates the replacement of the cookware.

Re:Stainless steel leaches nickel and chromium into foods du... by samatman on Thursday March 10, 2022 @09:31AM (#30627293)
> Unless a manufacturer provides the composition of the glaze used by them, you cannot know how safe it is.

Or you could just buy from any EU country:

https://www.european-enamel-association.eu/certification.htm...

Re:Stainless steel leaches nickel and chromium into foods du... by AlexandrB on Thursday March 10, 2022 @10:15AM (#30627813)
All this says about leeching is:

> 4.8 Specification and determination of the release of toxic elements

> The specification and determination of the release of toxic elements must comply with the requirements specified in the national laws of the country.

Most of the other requirements are about the mechanical properties of the enamel.

There's also this:

> 4.32 Determination and control of Lead and Cadmium release for hot water tanks

But that doesn't apply to cookware.

There's nothing here about requirements for the composition of the enamel or the making public thereof. And what constitutes a "toxic element" (and presumably the dosage) is left to the laws of each country. Most of these countries would consider stainless steel to meet their leeching requirements as well. So we're back to square one. There's no way to tell what the enamel is leeching. You just have an assurance that it's considered safe.

Re:Stainless steel leaches nickel and chromium into foods du... by carlmr on Thursday March 10, 2022 @09:39AM (#30627391)
>Enameled pans aren't going to leach anything...because any colorants added to the glaze will be rated as food safe

So we consider stainless steel pans as food safe generally, yet they do leach something. I don't see how food safe could imply that something doesn't leach. Only that we either think it doesn't leach too much or we don't think what it leaches is harmful.

Re:Stainless steel leaches nickel and chromium into foods du... by plasticchris on Thursday March 10, 2022 @08:56AM (#30626918)
Lots of old glazes used lead, so this isn’t always true. Can’t always judge by words or even appearances.
Re:Stainless steel leaches nickel and chromium into foods du... by samatman on Thursday March 10, 2022 @08:59AM (#30626943)
Sure, if you buy used enamel you can even get uranium. Which looks lovely but I wouldn't cook tomatoes in it.

This is why I specified "buy from a reputable manufacturer" because there is no risk of this whatsoever if you get contemporary / new cookware from the indicated regions; that list isn't exhaustive but I stand by this: any cookware you buy new from EU, America, or Japan, will not contain lead in the glaze, or anything else you wouldn't want to eat very small amounts of.

Re:Stainless steel leaches nickel and chromium into foods du... by nicoburns on Thursday March 10, 2022 @09:54AM (#30627576)
I heard that even well known brands like Le Creuset pots have lead in the ceramic coating on the outside of the pot. I guess that's not the same as being on the inside. But still, that seems not ideal.
Re:Stainless steel leaches nickel and chromium into foods du... by vannevar on Thursday March 10, 2022 @09:50AM (#30627534)
>Enameled cast iron (or enameled anything) is a fine choice, it comes with its own limitations culinarily (and advantages) but it isn't going leach anything into your food.

Has this been verified in practice? Is enamel always pure, or can it contain contaminants that can leach?

Re:Stainless steel leaches nickel and chromium into foods du... by morganslaw on Thursday March 10, 2022 @07:41AM (#30626242)
> 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/bes...

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @08:55AM (#30626897)
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.

Re:Stainless steel leaches nickel and chromium into foods du... by clsec on Thursday March 10, 2022 @09:31AM (#30627291)
I believe the process that you're describing is called powder coating [1].

[1] https://en.wikipedia.org/wiki/Powder_coating

Re:Stainless steel leaches nickel and chromium into foods du... by 83 on Thursday March 10, 2022 @10:33AM (#30628029)
The process to grow aluminum oxide on aluminum is called anodizing. Powder coating is almost entirely relegated to plastic coating afaik.
Re:Stainless steel leaches nickel and chromium into foods du... by clsec on Friday March 11, 2022 @09:55AM (#30640647)
You are correct, I misread OP's post.
Re:Stainless steel leaches nickel and chromium into foods du... by giantg2 on Thursday March 10, 2022 @09:07AM (#30627016)
And nonstick coatings can also off-gas and be damaged or deteriorate over time.

My big thing about this study is that they claim to use realistic cooking parameters. Some dishes may be cooked 6-20 hours, but how common is that? Wouldn't most dishes be under 1 hour and contain less acid? Seems like they're targeting worst case scenarios, which are plausibly realistic but not typical.

Re:Stainless steel leaches nickel and chromium into foods du... by dtagames on Thursday March 10, 2022 @08:41AM (#30626756)
Did we skip cast iron? Iron leeching into your food is actually a good thing. There are several brands of excellent cast iron cooking products which should be safe. Staub is one I like.
Re:Stainless steel leaches nickel and chromium into foods du... by christophilus on Thursday March 10, 2022 @08:56AM (#30626912)
I love my lodge pans. If you properly clean and oil them, they are as easy to use as non-stick alternatives. For a long while, I didn't believe this, but then I used my parent's pan one weekend, and it was a revelation. Turned out I'd never properly seasoned / kept my pans seasoned.
Re:Stainless steel leaches nickel and chromium into foods du... by guelo on Thursday March 10, 2022 @10:13AM (#30627780)
I wonder about that seasoning which is basically burned oil.
Re:Stainless steel leaches nickel and chromium into foods du... by humanlion87 on Thursday March 10, 2022 @09:58AM (#30627607)
Can you point to good a guide on how to use cast iron effeciently. I have been trying to use cast iron more regularly but end up getting frustrated. I feel like I am not taking the right steps to keep it seasoned. Whenever I cook food gets charred. For context, I do most of my cooking in non-stick cookware.
Re:Stainless steel leaches nickel and chromium into foods du... by StillBored on Thursday March 10, 2022 @12:56PM (#30630050)
The non-stick properties of seasoned cast iron are a bit overstated. Yes, its a lot better than stainless steel, or unseasoned, but any number of foods (eggs) will stick regardless of how much oil you add ahead of time. And unlike some of the nonstick coated pans, you always need at least some fat/oil in them during cooking.

So some of it is what you expect, cast iron is basically non stick for lots of things (AKA I would never use anything other than cast iron for pancakes/etc), but I keep a couple Henckels Capri Notte Granitium pans we picked up at cosco handy for the morning eggs. Those seem to be the survivors at this point of a long series of trial and error with non-teflon coatings, most of which seem to work fine for a month or two and then are non stick at the same level as one might expect from cast iron. I have no idea how much I've spent buying pans a few times a year at $20-50 a pop to replace worn out nonstick over the past 10 years.

Re:Stainless steel leaches nickel and chromium into foods du... by 0ldskool on Friday March 11, 2022 @04:16PM (#30646111)
I exclusively use my cast iron for cooking eggs & bread. There is zero sticking. I also use grape-seed oil.

I make french toast, omelettes, over easy eggs, and toast. I have never had sticking that you are talking about...

Re:Stainless steel leaches nickel and chromium into foods du... by eatbitseveryday on Thursday March 10, 2022 @01:21PM (#30630417)
Eggs stick much less if you use butter instead of oil on your pan.
Re:Stainless steel leaches nickel and chromium into foods du... by StillBored on Thursday March 10, 2022 @01:27PM (#30630500)
I use butter with eggs already, even on the nonstick, because it tastes better.
Re:Stainless steel leaches nickel and chromium into foods du... by Grimm665 on Thursday March 10, 2022 @11:14AM (#30628553)
I wash my cast iron pan after each use, sometimes just with very hot water and sometimes with a little soap if I need it, but I always thoroughly dry the pan and do a quick re-seasoning afterwards. This is just a quick wipe down with a paper towel with a dab of oil on it, and I leave it on my stove top with the (electric) burner on low for about 30 minutes.

A good tip I read is to wipe down the pan with such a thin layer of oil that it's as if you made a mistake and want to remove the oil with just the paper towel instead. It should really be as thin as possible, and you'll see it sort of glaze over as it drys on the stove top. After about 6 months of this, using the pan about once a week, it has been truly non-stick for a while.

Basically following this guide: https://www.cuisinel.com/care-use

Re:Stainless steel leaches nickel and chromium into foods du... by boilerupnc on Thursday March 10, 2022 @10:31AM (#30627999)
After a lake vacation in western NC, I stumbled across my first Griswold Cast Iron pan. The bug hit me and I've collected a couple of others since then. My favorite so far is the Colonial Skillet Griswold 666 (aka Satan's Helper). Makes an amazing mix of eggs, potatoes and bacon. I started looking up the best way to season these pans and found [0] and [1] very insightful.

[0] https://sherylcanter.com/wordpress/2010/01/a-science-based-t...

[1] https://sherylcanter.com/wordpress/2010/02/black-rust-and-ca...

Re:Stainless steel leaches nickel and chromium into foods du... by sul_tasto on Thursday March 10, 2022 @06:28PM (#30634045)
It’s often helpful to sand & polish cast iron skillets before seasoning them. You just have to take precautions so you don’t inhale the metal shavings. Here’s a good reference: https://youtu.be/2wHZ7hKpPUs

Also, the type of oil you use to season your cast iron cookware is important. You should use flaxseed, grapeseed or avocado oil. Do not use olive oil, because it has an extremely low smoke point. Canola and vegetable/soybean oils are unhealthy.

Re:Stainless steel leaches nickel and chromium into foods du... by seanc on Thursday March 10, 2022 @11:37AM (#30628857)
Humour is generally discouraged on hacker news, but this is too spot-on to resist:

https://xkcd.com/1905/

Re:Stainless steel leaches nickel and chromium into foods du... by dtagames on Friday March 11, 2022 @10:00AM (#30640706)
There are million anecdotal methods on how to care for cast iron, but this TL;DR works for me: Use some kind of oil when you're cooking. Hand wash them and never put them in the dishwasher. And coat with a thin spray of olive oil (the "oil only" sprays are great) after use and buff with a paper towel. Never leave anything on the iron surface except a light coating of oil. Don't let them air dry. That works for me! :-)
Re:Stainless steel leaches nickel and chromium into foods du... by KolenCh on Thursday March 10, 2022 @05:04PM (#30633096)
The list is missing one common type of cookware—cast iron.
Re:Stainless steel leaches nickel and chromium into foods du... by api on Thursday March 10, 2022 @06:40AM (#30625818)
What about cast iron? It’s very nice to cook with and popular with chefs.
Re:Stainless steel leaches nickel and chromium into foods du... by mrspuratic on Thursday March 10, 2022 @06:49AM (#30625884)
When correctly used it only leaches about the last 100 meals into your next meal :)
Re:Stainless steel leaches nickel and chromium into foods du... by hawski on Thursday March 10, 2022 @04:33AM (#30625011)
Wouldn't iron be the best at least for pans? Also what about enamel?
Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @04:40AM (#30625058)
Any kind of iron cookware leaches in food a quantity of iron that is many orders of magnitude greater than all metals leached by stainless steel.

Fortunately, excessive quantities of iron in food are not dangerous for most people, even when the quantity is great enough to give an unpleasant taste to the cooked food.

In any case, iron cookware is preferable to ceramic/plastic/non-sticking cookware of unknown chemical composition.

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @05:51AM (#30625472)
About enamel, that is a complex mixture of various oxides.

All colored enamels have undesirable components.

White enamel can be made perfectly safe for food contact. Unfortunately, being white is not a guarantee for that.

Manufacturers are tempted to include in the enamel composition various oxides that improve the manufacturing properties, e.g. which increase the fluidity of the melted enamel, or which enhance the adherence of the enamel to the base metal, and so on. These additives may leach unwanted substances.

So one may use cookware with white enamel, if they trust that the manufacturer was not too greedy to reduce their costs.

Ideally there should be a law to force all manufacturers of cookware to publish the precise chemical composition of any material used for food contact, like there are laws for labels with the approximate food composition.

Until then, it is safer to distrust any kind of coatings, plastics, enamels or glazes with secret compositions, because in the past there were many bad surprises whenever any of these were analyzed.

Re:Stainless steel leaches nickel and chromium into foods du... by Etherlord87 on Thursday March 10, 2022 @04:45AM (#30625081)
I like the way you think. If you have a pan made of food, does it matter if some food leaches to your food? For a person with iron deficiencies it's hard to argue additional iron is bad, however...

Once your iron gets into contact with oxygen, you will no longer consume iron, you will consume rust...

Re:Stainless steel leaches nickel and chromium into foods du... by amelius on Thursday March 10, 2022 @04:50AM (#30625102)
Solution: don't use "unsafe" Rust.
Re:Stainless steel leaches nickel and chromium into foods du... by ungamed on Thursday March 10, 2022 @07:26AM (#30626136)
Oh stop you.
Re:Stainless steel leaches nickel and chromium into foods du... by wiz21c on Thursday March 10, 2022 @04:54AM (#30625126)
ah ah ah !
Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @06:02AM (#30625564)
Actually what you need in your body is rust, i.e. iron ions.

Metallic iron cannot be used in any way by living beings, before it is oxidized to rust.

The leaked iron from cookware is already in the form of "rust", more precisely the iron is leached after it is oxidized to iron ions. The ions with 2 elementary charges remain dissolved in the water, and they may be absorbed by the body, while the iron ions with 3 elementary charges (these are the components of rust in the strict sense, i.e. of red iron oxide) will normally precipitate into red rust crystals, which will pass through the digestive tract mostly without being absorbed (a few might be reduced to ions with 2 charges, and then be absorbed).

Re:Stainless steel leaches nickel and chromium into foods du... by Spivakov on Thursday March 10, 2022 @05:19AM (#30625261)
I am not an expert but it seems that the form of iron absorbed by human body is ferrous sulfate, iron in +2 oxidation state. Iron rust of iron pan is in +3 state, which is chemically a different thing.
Re:Stainless steel leaches nickel and chromium into foods du... by voxadam on Thursday March 10, 2022 @07:45AM (#30626273)
Your comment reminds me of the Lucky Iron Fish[0] developed in Cambodia as an iron supplement for populations plagued by iron-deficient anemia.

[0] https://en.wikipedia.org/wiki/Lucky_iron_fish

Re:Stainless steel leaches nickel and chromium into foods du... by unfocussed_mike on Thursday March 10, 2022 @08:05AM (#30626451)
You beat me to this!

https://www.bbc.co.uk/news/health-32749629

You can buy them in the west now (even on Amazon I think):

https://luckyironfish.com/

Re:Stainless steel leaches nickel and chromium into foods du... by Synaesthesia on Thursday March 10, 2022 @05:18AM (#30625252)
I think a lot of the iron in the body is already in ionic form, so it's not a huge concern.
Re:Stainless steel leaches nickel and chromium into foods du... by cycomanic on Thursday March 10, 2022 @09:45AM (#30627478)
The issue with iron cookware (and I'm a big fan) is cooking acidic dishes in them (which are the ones that mainly cause the leeching) you destroy the seasoning and they become a bit of a pain to clean after that.
Re:Stainless steel leaches nickel and chromium into foods du... by cjg on Thursday March 10, 2022 @06:36AM (#30625790)
Iron pans are not the best for those with hemochromatosis (iron overload).
Re:Stainless steel leaches nickel and chromium into foods du... by bagels on Thursday March 10, 2022 @06:09AM (#30625624)
Is iron cookware really just iron, or is it alloyed slightly?
Re:Stainless steel leaches nickel and chromium into foods du... by Bud on Thursday March 10, 2022 @07:05AM (#30625990)
A little bit of carbon (2-4%) and silicon. Otherwise it's just iron.

It should also be noted that with a properly seasoned cast iron pan, the food isn't interacting as much directly with the iron, since the seasoning layer (polymerized fats) is in the way.

Re:Stainless steel leaches nickel and chromium into foods du... by dataflow on Thursday March 10, 2022 @05:32AM (#30625334)
Where does Teflon fit in this hierarchy?

And by "ceramic" I assume you mean the faux-"ceramic-coated" ones that don't actually contain ceramic, right?

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @05:41AM (#30625410)
Pure ceramic is porous, so it is never used in direct contact with food, because the food will be absorbed in the pores.

In all cookware where the body is ceramic, the surface is covered with some glaze, enamel or plastic coating, which is the material that really counts for food contact.

Re:Stainless steel leaches nickel and chromium into foods du... by ftrobro on Thursday March 10, 2022 @06:36AM (#30625793)
Unglazed clay pots have been used for thousands of years, I have one myself. You soak it in water for 15 minutes before putting the food in.

https://www.youtube.com/watch?v=7EbdBty-40I

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @07:15AM (#30626059)
You are right that unglazed pottery had been used for many thousands of years, before glazing was invented.

The information about soaking is interesting.

I was not aware of it, because there are many countries were unglazed pottery is no longer used, at least I have never seen any of it used for food contact, but only for different purposes.

Re:Stainless steel leaches nickel and chromium into foods du... by morganslaw on Thursday March 10, 2022 @07:40AM (#30626232)
So is ceramic cookware safe? This stuff here: https://www.goodhousekeeping.com/cooking-tools/a26078798/bes... Basically you are saying we have no clue what is actually in contact with our food?
Re:Stainless steel leaches nickel and chromium into foods du... by mschuster91 on Thursday March 10, 2022 @05:51AM (#30625481)
The problem with modern Teflon is mostly that people overheat their non-stick pans. The stuff is chemically inert otherwise.

Older Teflon pans and cookware have the problem of PFOA contamination, but that's IIRC been banned for years now.

Re:Stainless steel leaches nickel and chromium into foods du... by Lev1a on Thursday March 10, 2022 @07:46AM (#30626280)
> The problem with modern Teflon is mostly that people overheat their non-stick pans

Also using metal or other "hard" implements in those non-stick pots/pans, which damages the non-stick layer allowing it to flake away into the food prepared in it over time.

Re:Stainless steel leaches nickel and chromium into foods du... by bigDinosaur on Thursday March 10, 2022 @06:29AM (#30625749)
If someone responds that a material is 'chemically inert' when we're talking about heating things up, I don't think I'd have much confidence that it's not leaching into my food.
Re:Stainless steel leaches nickel and chromium into foods du... by gilbetron on Thursday March 10, 2022 @10:38AM (#30628101)
It's really tough to overheat a non-stick pan - you have to get above 500F for it to even maybe be a problem.
Re:Stainless steel leaches nickel and chromium into foods du... by telchior on Thursday March 10, 2022 @01:02PM (#30630147)
Not quite. Off-gassing begins at a bit under 400F. And the assumption that it's "really tough" to reach either temperature (400 or 500F) is wildly incorrect for the realities of cheap stovetops around the world. Gas / propane is widely used and can cause teflon to begin smoking within a minute or two.

But yes, it's probably fine on your fancy glass induction stovetop.

Re:Stainless steel leaches nickel and chromium into foods du... by guelo on Thursday March 10, 2022 @10:25AM (#30627920)
Imagine a cooking pan that can't be heated.
Re:Stainless steel leaches nickel and chromium into foods du... by eternityforest on Thursday March 10, 2022 @05:01AM (#30625155)
I'm not entirely convinced that plastics are categorically bad. I suspect they are better than stainless for long term storage of certain things.

There's a lot of plastics that don't commonly get used but are food rated in industrial applications, it would be cool to see them thoroughly evaluated and if they are safe, made into consumer items.

Ceramics are scary because a few have lead in them, but there are safe ones(Just not that you can afford), they're used for surgical implants.

I wonder what the possibilities are with magnesium. It can be extracted from the ocean and is nontoxic enough to just put back where you found it, so it seems to be the closest we have to a renewable metal.

There's also laser etched lotus effect patterns. Do metals still leach after you make them hydrophobic like that? Could you make magnesium corrosion resistant enough?

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @06:11AM (#30625637)
The base components of many plastics, e.g. polypropylene, polyethylene, acrylic glass, are perfectly safe for food contact.

The problem is that all plastics contain various additives, which are normally not disclosed by the manufacturer, even in the plastic grades that are approved for food contact.

The risks caused by unknown plastic additives are especially large when the plastics are used above room temperature, e.g. for heating food in a microwave oven.

Storing food in polypropylene vessels or polyethylene bags in a refrigerator is likely to be perfectly safe.

Re:Stainless steel leaches nickel and chromium into foods du... by selimnairb on Thursday March 10, 2022 @07:35AM (#30626199)
Irrespective of safety, plastic fares poorly for me for taste reasons. Most soaps and detergents contain fragrances that seem to persistently bind to plastic food containers. The exception are soap products like Seventh Generation, which seem to contain less harsh/”natural” fragrances, which don’t seem to be as persistent. As it is, most foods stored in most plastic containers washed by most soaps taste like soap to me. For this reason alone, I avoid plastic where possible.
Re:Stainless steel leaches nickel and chromium into foods du... by grecy on Thursday March 10, 2022 @06:30AM (#30625753)
> The base components of many plastics, e.g. polypropylene, polyethylene, acrylic glass, are perfectly safe for food contact.

We fully believed BPA was "perfectly safe for food contact" for many, many years. Now of course we know that's not true.

It's always worth remembering to add as far as we know today.

There are hundreds of such examples. What we know today isn't necessarily a hard fact, it's just as good as we know with today's knowledge.

Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @07:01AM (#30625955)
No competent chemist could have ever thought that BPA is a safe substance.

Some chemists have believed that the risks of depolymerization for the plastics that are made with BPA, e.g. polycarbonate, are low, so the risk of BPA leaching into food is low. However there have always been many chemists who have believed that the risks are too high for any such plastic to be considered as safe for food contact.

The problem is that the relevant true experts are almost never consulted for decisions regarding the use of materials for various purposes. Those who are consulted have usually very narrow specializations and can have informed opinions only about a part of the relevant criteria. The final decision about the use of materials is usually done strictly by financial criteria.

Some chemists have found a method to make polycarbonate, a plastic that combined useful properties, like high transparency and high impact resistance. They did not think about which are good uses for it and which are bad uses for it, it was not their job. Then someone else has developed a cheap method to make bottles out of it, also without giving much thought about what is suitable to be stored in such bottles or not, it was not their job. Eventually someone else has decided to fill PC bottles with some beverage and sell them.

The error has been at the end, because any material used for food-contact should be scrutinized much more than for almost any other purposes. There already are laws and regulations about materials for food-contact, but they are neither strict enough, nor applied correctly most of the time.

While there have been many problems with plastics used for inappropriate purposes, there are a lot of similar examples with all kinds of materials, crystal glass with lead used for many centuries (fortunately only the rich could afford it), silver-mercury amalgam used in dentistry for more than a century, uranium glazes and many others.

We can only learn from past mistakes and improve the existing legislation.

In my opinion, the most important would be a law forcing any manufacturer to publish the exact chemical composition of any material that is used for food-contact in their products.

This actually does not leak any valuable trade secret. Anyone with enough money can make a precise chemical elemental analysis of any object, only individual customers cannot afford it.

The valuable trade secrets are in the details of the manufacturing process, not in the final product, which can be analyzed by any competitor.

Re:Stainless steel leaches nickel and chromium into foods du... by eternityforest on Thursday March 10, 2022 @03:35PM (#30632090)
Y
Re:Stainless steel leaches nickel and chromium into foods du... by eternityforest on Thursday March 10, 2022 @03:37PM (#30632111)
BPA is probably still safer than the actual food we eat out of it... Especially the soda.

Although food seems to be improving(But getting more expensive at the same time) and BPA isn't good.

Re:Stainless steel leaches nickel and chromium into foods du... by kmmlng on Thursday March 10, 2022 @05:05AM (#30625174)
> I suspect they are better than stainless for long term storage of certain things.

I'm confused, how is that relevant to the topic at hand?

Re:Stainless steel leaches nickel and chromium into foods du... by aperson_hello on Thursday March 10, 2022 @10:04AM (#30627668)
Another potential problem with magnesium is its flammability. Look up magnesium fire and you'll understand. Maybe not that likely in most settings (it takes a bit to get it going), but a forgotten pot on a gas burner would worry me.
Re:Stainless steel leaches nickel and chromium into foods du... by adrian_b on Thursday March 10, 2022 @06:15AM (#30625663)
As you have said, the problem with magnesium is that it corrodes too easily, so it is not used, even if it is perfectly safe for food contact.
Re:Stainless steel leaches nickel and chromium into foods du... by formvoltron on Thursday March 10, 2022 @09:01AM (#30626962)
Also cast iron and carbon steel both leach iron into food. Iron is now known to cause stress to cells and can even initiate a special form of cell death.
Re:Stainless steel leaches nickel and chromium into foods du... by giantg2 on Thursday March 10, 2022 @09:13AM (#30627073)
Iron is also known to be essential for human health and intentionally added to many foods.

I can't tell, but maybe your comment was calling that out sarcastically.

Re:Stainless steel leaches nickel and chromium into foods du... by clsec on Thursday March 10, 2022 @09:24AM (#30627206)
Not OP but many people (1 in 300 Caucasians [1]) need to closely watch and minimize their iron intake because they have hereditary hemochromatosis. With hemochromatosis ones body cannot process iron. There is no cure and the only way to deal with it is to minimize iron intake and, if iron levels are too high, blood letting (phlebotomy).

[1] https://www.cdc.gov/genomics/disease/hemochromatosis.htm

edit: forgot URL

Re:Stainless steel leaches nickel and chromium into foods du... by tonyarkles on Thursday March 10, 2022 @10:20AM (#30627869)
> if iron levels are too high, blood letting (phlebotomy)

A friend discovered a few years ago that he has (developed?) hemochromatosis. From what I understand, in Canada the "prescription" for this is to diligently donate blood to Canada Blood Services, I think more frequently than the general public is allowed to. He's got an awesome blood donation record now!

Re:Stainless steel leaches nickel and chromium into foods du... by clsec on Friday March 11, 2022 @10:03AM (#30640742)
You can't "develop" hereditary hemochromitosis [1]. It is a genetic disorder. Both parents need to carry specific genes that when combined in the child cause hereditary hemochromitosis.

I don't know about Canada but in the US it is illegal to donate blood when you have hemochromatosis. I get phlebotomy every other month (for the past 10 yrs) and my blood is always thrown away.

[1] https://rarediseases.info.nih.gov/diseases/10746/hemochromat...

Re:Stainless steel leaches nickel and chromium into foods du... by clsec on Friday March 11, 2022 @10:08AM (#30640792)
I should have added that, yes, you can develop hemochromatosis. Just not the hereditary type.
Re:Stainless steel leaches nickel and chromium into foods du... by tonyarkles on Friday March 11, 2022 @06:35PM (#30647466)
Looks like it's a-ok in Canada, given that you're otherwise healthy: https://www.blood.ca/en/blood/am-i-eligible-donate-blood/abc...

I have no clue if his was hereditary or not, I just remember him going to Mexico, feeling funky about half-way through the trip, and his doctor diagnosed it when he got home. Would've been in his 20s.

Re:Stainless steel leaches nickel and chromium into foods du... by clsec on Saturday March 12, 2022 @08:11AM (#30651102)
So this conversation has gotten me to research this topic a little bit more. I'm not exactly sure if it's actually illegal in the U.S., that's just what the nurses who do my phlebotomy have told me. Though I did find that the American Red Cross does not accept blood from individuals who have hereditary hemochromatosis [1].

My case was discovered when my doctor did an iron work-up as part of checking out my liver. The normal level in men is 12-300 nanograms per milliliter (ng/mL). Mine was very close to 1000 ng/mL at the time. These days my hematologist likes to keep me in the 50-75 ng/mL range.

[1] https://www.redcrossblood.org/donate-blood/blood-donation-pr...

Re:Stainless steel leaches nickel and chromium into foods du... by kube-system on Thursday March 10, 2022 @09:34AM (#30627324)
Many more people (1 in 7) have iron-deficiency anemia.
Re:Stainless steel leaches nickel and chromium into foods du... by a9h74j on Thursday March 10, 2022 @10:42AM (#30628146)
So many multivitamins, etc, omit iron out of fear of iron poisoning, that one can easily err on an individually-deficient side.

(The optimal window also appears narrow enough -- even people with temporary anemia must limit supplements -- that I would not attempt to rely on cookware to supply my iron requirements.)

Re:Stainless steel leaches nickel and chromium into foods du... by kube-system on Thursday March 10, 2022 @12:16PM (#30629429)
I'm definitely not suggesting that iron pans should be a dietary supplement. I'm just doubtful that they're responsible for much iron poisoning.
Re:Stainless steel leaches nickel and chromium into foods du... by a9h74j on Thursday March 10, 2022 @06:11PM (#30633896)
Yes, my parenthetical add-on was directed at the comments in general, not your comment. I did not intend to imply that you implied...
Re:Stainless steel leaches nickel and chromium into foods du... by AlexandrB on Thursday March 10, 2022 @10:20AM (#30627866)
When I was a kid I noticed that Cheerios are notably high in iron. I threw a bunch of Cheerios into a cup of water and let it mix for many hours on a chemical mixer. The iron fell out and stuck to the stirrer magnet as a small amount of iron filings.

Is this dietary iron different from the iron you get from a pan? Or do Cheerios cause stress to cells and a special form of cell death?

Re:Stainless steel leaches nickel and chromium into foods du... by Tagbert on Thursday March 10, 2022 @12:40PM (#30629836)
I suspect that that iron is not bio-available and so does not provide much nutritional benefit. To be available for absorption, you want an iron salt such as ferrous gluconate that is soluble in water and can be integrated by cells.
Re:Stainless steel leaches nickel and chromium into foods du... by aceazzameen on Thursday March 10, 2022 @10:28AM (#30627962)
I've always wondered about the patina, or carbonized oil, on my cast iron and carbon steel pans. That stuff leeches over time too, and it's probably carcinogenic? Have there ever been any studies on the seasonings on those pans and any potential health effects?

That being said, I love my pans and probably wouldn't stop using them.

Re:Stainless steel leaches nickel and chromium into foods du... by inimino on Thursday March 10, 2022 @08:17PM (#30634990)
If you cook with oil and heat, regardless of the cookware you're already eating some amount of burnt oil. At least, that is how I think about it...
Re:Stainless steel leaches nickel and chromium into foods du... by margalabargala on Thursday March 10, 2022 @09:17AM (#30627135)
This is not useful information if not combined with the quantities involved. It's like warning that drinking water is known to raise your blood pressure and has even caused people to die of heart attacks. It's true, but not in the quantities a person usually encounters.
Re:Stainless steel leaches nickel and chromium into foods du... by giaour on Thursday March 10, 2022 @09:18AM (#30627139)
I thought this was actually an important source of dietary iron in the early modern period, though that may be apocryphal.
Re:Stainless steel leaches nickel and chromium into foods du... by Maursault on Thursday March 10, 2022 @07:25AM (#30626131)
> glass, while perfect for storage, is not suitable for most types of cooking

Such as? Could be I'm simply unaware of "most types of cooking."

Re:Stainless steel leaches nickel and chromium into foods du... by lkxijlewlf on Thursday March 10, 2022 @08:38AM (#30626726)
Sauteing. Frying. Well, pretty much any stove top cooking.

I mean, sure, if we want to "well technically" the hell out of it, one could probably use glass if you're careful. But one also has to consider safety and convenience.

Re:Stainless steel leaches nickel and chromium into foods du... by curiousllama on Thursday March 10, 2022 @07:34AM (#30626191)
Wouldn’t a glass frying pan shatter?
Re:Stainless steel leaches nickel and chromium into foods du... by jdironman on Thursday March 10, 2022 @07:49AM (#30626310)
It would indeed. I know this, because I left a glass casserole dish on a hot stove eye when I was young. A while later it exploded and the kitchen floor was marred with little burns from glass "meteorites " from the explosion. Thankful no one was in the kitchen to say the least.
Re:Stainless steel leaches nickel and chromium into foods du... by unfocussed_mike on Thursday March 10, 2022 @07:55AM (#30626372)
Pyrex made a range of "flameware" frying pans that you can still sometimes find on eBay, using an "aluminosilicate" glass. Sold them for forty years.

There are a few details about Flameware here.

https://gizmodo.com/the-pyrex-glass-controversy-that-just-wo...

You can find them on eBay still. I definitely wouldn't use one; they seem utterly impractical. They must be heavy, they are small, and the clip-on, rather than bolt-on handles are going to be rusted and dodgy at this point. You can see why they chose that strategy (to avoid a heat stress point around a bolt) but it can't be without its risks.

Re:Stainless steel leaches nickel and chromium into foods du... by Werewolf255 on Thursday March 10, 2022 @08:10AM (#30626494)
I've got a 'flameware' saucepan and it works great. Very light and visually interesting, but I put it away for special because I'm always worried I'll break it. The strap and clip handle is fine on my pan but it does seem like it needs to be tightened up every so often,so I could see it being a common point of failure.
Re:Stainless steel leaches nickel and chromium into foods du... by hammock on Thursday March 10, 2022 @07:53AM (#30626350)
Anything on a stove or in a fire
Re:Stainless steel leaches nickel and chromium into foods du... by moltke on Thursday March 10, 2022 @07:58AM (#30626393)
Intuitively I feel like you could probably get away with borosilicate (certainly quartz if just have nothing better to spend your money on) on top of an electric stove.
Re:Stainless steel leaches nickel and chromium into foods du... by killingtime74 on Thursday March 10, 2022 @12:24PM (#30629550)
You can also use glass only if you use an oven
Re:Stainless steel leaches nickel and chromium into foods du... by nayuki on Thursday March 10, 2022 @01:19PM (#30630385)
Even then, you have to worry about glass shattering due to thermal shock. https://www.youtube.com/watch?v=UyhdMa1ikKM
Re:Stainless steel leaches nickel and chromium into foods du... by bbarnett on Thursday March 10, 2022 @08:39AM (#30626742)
What bothers me is, people washing and scrubbing their frying pans.

I cook in stainless, and after done just put it in the sink with water. After I eat the food, maybe a half hour later, just dump the water and wipe it with a rag.

Point is, why remove the grease, why remove the seasoned crust on pan. Do people take soap and scrub brush to their bbq too?

You don't need to soap wash, or scrub a frying pan.

This sort of behaviour likely keeps leeching to a minimum, compared to vigorously scrubbing and cleaning each use.

Re:Stainless steel leaches nickel and chromium into foods du... by bbarnett on Thursday March 10, 2022 @10:08AM (#30627714)
Up and down the votes do go,

Ew! Gross, down you know,

Ha, right, up they sow,

Digust is truth's foe!

Re:Stainless steel leaches nickel and chromium into foods du... by bbarnett on Thursday March 10, 2022 @10:14AM (#30627803)
can't believe what i just saw,

horrid, ew, sticks in my craw,

vote it down, hide the truth,

blocked from sight, show no ruth,

cause it's just so uncouth

Re:Stainless steel leaches nickel and chromium into foods du... by ramijames on Thursday March 10, 2022 @08:47AM (#30626811)
Curious where copper falls in this list.
Re:Stainless steel leaches nickel and chromium into foods du... by giaour on Thursday March 10, 2022 @09:24AM (#30627198)
Copper is more reactive than steel. Copper cookware (with some rare exceptions) is lined with another metal to prevent food from direct contact with copper during cooking. Traditionally, a thin layer of tin is used for this purpose, though modern copper cookware can sometimes use steel or anodized aluminum.
Re:Stainless steel leaches nickel and chromium into foods du... by eatbitseveryday on Thursday March 10, 2022 @10:35AM (#30628059)
What of cast iron?
Re:Stainless steel leaches nickel and chromium into foods du... by TAKEMYMONEY on Thursday March 10, 2022 @10:50AM (#30628251)
It leaches iron. Not "heme iron" (like that found in meat), it isn't absorbed as easily.

This is affected by a number of factors including the acidity of the food, how new the pan is, and how the pan is seasoned

https://ift.onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2...

https://pubmed.ncbi.nlm.nih.gov/10073514/

Re:Stainless steel leaches nickel and chromium into foods du... by aeternum on Thursday March 10, 2022 @11:57AM (#30629163)
Iron from the pan is not absorbed as easily as the iron in foods but it is still generally good for you rather than bad for you (like chromium).

If kids are low in iron, doctors still recommend cooking using iron pots & pans (in addition to supplements).

Re:Stainless steel leaches nickel and chromium into foods du... by TAKEMYMONEY on Thursday March 10, 2022 @12:06PM (#30629288)
I found this related study interesting:

> Ethiopian children fed food from iron pots had lower rates of anaemia and better growth than children whose food was cooked in aluminium pots [1]

And to your point about Chromium, the type of iron leached by cast iron may not contribute to cardiovascular disease (the same way as heme iron) [2]

https://pubmed.ncbi.nlm.nih.gov/10073514/

https://pubmed.ncbi.nlm.nih.gov/25439662/

Re:Stainless steel leaches nickel and chromium into foods du... by aeternum on Thursday March 10, 2022 @10:47PM (#30635925)
I cannot access the full-text of the second article, but is it really thought that heme iron is the component of red meat that contributes/causes cardiovascular disease?

Did the authors somehow adjust for the fact that a high heme iron intake generally implies a diet high in red meat?