# Safety of cast iron cookware? **URL:** \ **Category:** Factual Questions\ **Created:** [October 24, 2007, 3:29pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825 "2007-10-24T15:29:28Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![Manduck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manduck/32/256_2.png) [@Manduck](https://boards.straightdope.com/u/Manduck)\ **Post date:** [October 25, 2007, 1:54am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/21 "2007-10-25T01:54:44Z")
[QUOTE=jjimm] I suggest that we eat only lab-produced food substitute substitute created in a sterile laboratory environment and injected into our mouths by robots. [/QUOTE] Robots? Count me in! ---
**Author:** ![1010011010](https://avatars.discourse-cdn.com/v4/letter/1/ea666f/32.png) [@1010011010](https://boards.straightdope.com/u/1010011010)\ **Post date:** [October 25, 2007, 2:08am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/22 "2007-10-25T02:08:16Z")
[QUOTE=Joey P] Also hot metal and cold metal look exactly the same. [/QUOTE] Unless you can see in near infared… in which case hot metal looks “fuzzy”. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 25, 2007, 2:25am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/23 "2007-10-25T02:25:06Z")
[This web page](http://www.oliveoilsource.com/oliveoildr-cancer.htm) says: > [@](#): > > Polycyclic aromatic hydrocarbons are a group of chemicals which are formed when petroleum, petroleum products, coal, wood, cellulose, corn, or oil are burned. … Burning any cooking oil can increase the amounts of PAHs. Oil of any kind which has been repeatedly heated to its smoking point will lose it’s natural antioxidants and begin to accumulate free radicals and other cancer causing substances. Whether this has actually caused cancer in humans has never been proven. So it seems like the “carcinogen” claim has _some_ basis in reality, if we believe the above cite. ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [October 25, 2007, 2:53am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/24 "2007-10-25T02:53:27Z")
[QUOTE=scr4] So it seems like the “carcinogen” claim has _some_ basis in reality, if we believe the above cite. [/QUOTE] Thankfully, being human, I feel pretty safe. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [October 25, 2007, 3:46am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/25 "2007-10-25T03:46:50Z")
[Chevy Chase] This report just in: Cancer is caused by white mice. [/Chevy Chase] ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [October 25, 2007, 4:55am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/26 "2007-10-25T04:55:00Z")
[QUOTE=AskNott] That’s okay. An iron-rich diet won’t hurt you, and you won’t rust. [/QUOTE] Yes, too much iron can be hazardous to ones health. Especially for men. wiki: "Excessive iron can be toxic, because free ferrous iron reacts with peroxides to produce free radicals, which are highly reactive and can damage DNA, proteins, lipids, and other cellular components. Thus, iron toxicity occurs when there is free iron in the cell, which generally occurs when iron levels exceed the capacity of transferrin to bind the iron. Iron uptake is tightly regulated by the human body, which has no physiological means of excreting iron, so controls iron levels solely by regulating uptake. Although uptake is regulated, large amounts of ingested iron can cause excessive levels of iron in the blood, because high iron levels can cause damage to the cells of the gastrointestinal tract that prevents them from regulating iron absorption. High blood concentrations of iron damage cells in the heart, liver and elsewhere, which can cause serious problems, including long-term organ damage and even death. Humans experience iron toxicity above 20 milligrams of iron for every kilogram of mass, and 60 milligrams per kilogram is a lethal dose.[15] Over-consumption of iron, often the result of children eating large quantities of ferrous sulfate tablets intended for adult consumption, is one of the most common toxicological cause of death in children under six.[15] The DRI lists the Tolerable Upper Intake Level (UL) for adults as 45 mg/day. For children under fourteen years old the UL is 40 mg/day. Regulation of iron uptake is impaired in some people as a result of a genetic defect that maps to the HLA-H gene region on chromosome 6. In these people, excessive iron intake can result in iron overload disorders, such as hemochromatosis. Many people have a genetic susceptibility to iron overload without realizing it or being aware of a family history of the problem. For this reason, it is advised that people should not take iron supplements unless they suffer from iron deficiency and have consulted a doctor. Hemochromatosis is estimated to cause disease in between 0.3 and 0.8% of Caucasians. [16] The medical management of iron toxicity is complex, and can include use of a specific chelating agent called deferoxamine to bind and expel excess iron from the body." Generally,most women need more iron, but many males can get by fine with less. I suggest us male Dopers make their Vitamin choice one without Iron. Otherwise a fine post. ---
**Author:** ![chorpler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chorpler/32/2888_2.png) [@chorpler](https://boards.straightdope.com/u/chorpler)\ **Post date:** [October 25, 2007, 11:40am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/27 "2007-10-25T11:40:18Z")
[QUOTE=DrDeth] Yes, too much iron can be hazardous to ones health. Especially for men. \ Generally,most women need more iron, but many males can get by fine with less. I suggest us male Dopers make their Vitamin choice one without Iron. [/QUOTE] I was going to ask about the articles that were going around the news sites a few years back saying that high iron was linked to heart attacks, and that pre-menopausal women were okay because they got rid of iron by menstruating, but that men and post-menopausal women should donate blood as often as possible to decrease their heart attack risk. Were those articles just scaremongering, or is the “iron = heart attacks = donate blood to avoid” thing regarded as accurate? ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [October 25, 2007, 11:49am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/28 "2007-10-25T11:49:10Z")
[QUOTE=chorpler] I was going to ask about the articles that were going around the news sites a few years back saying that high iron was linked to heart attacks, and that pre-menopausal women were okay because they got rid of iron by menstruating, but that men and post-menopausal women should donate blood as often as possible to decrease their heart attack risk. Were those articles just scaremongering, or is the “iron = heart attacks = donate blood to avoid” thing regarded as accurate? [/QUOTE] My understanding is that it can be a _slight_ danger in men, _unless_ they have a rare medical condition which causes the body to have too much iron in the blood. The treatment for this is frequent blood donations. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 25, 2007, 11:54am UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/29 "2007-10-25T11:54:38Z")
[QUOTE=1010011010] Unless you can see in near infared… in which case hot metal looks “fuzzy”. [/QUOTE] Wouldn’t it just look ‘glowy’? ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [October 25, 2007, 5:00pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/30 "2007-10-25T17:00:10Z")
Free the Radicals!! And, speaking of folklore, that old thing about being mad enough to chew nails and spit sparks is just a figure of speech. Anger won’t influence your mineral intake. ---
**Author:** ![Geobabe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/geobabe/32/3908_2.png) [@Geobabe](https://boards.straightdope.com/u/Geobabe)\ **Post date:** [October 25, 2007, 5:43pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/31 "2007-10-25T17:43:03Z")
The article **DrDeth** cites addresses iron supplements, but doesn’t mention cookware, so I’m curious if there are any figures out there for just how much iron a cast iron pan adds to food; sure, it’s always mentioned as a great way to add iron to your diet, but I’ve never seen any actual numbers. I wonder if it really would ever be an issue, even for people who need to watch their iron intake. ---
**Author:** ![Geobabe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/geobabe/32/3908_2.png) [@Geobabe](https://boards.straightdope.com/u/Geobabe)\ **Post date:** [October 25, 2007, 5:54pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/32 "2007-10-25T17:54:54Z")
Actually, I just answered my own question with the right Google terms-- [http://whatscookingamerica.net/Information/IronCastIron.htm](http://whatscookingamerica.net/Information/IronCastIron.htm) A pretty significant increase in iron content for some of those foods, so it could make a big difference for somebody with iron uptake problems. ---
**Author:** ![Gfactor](https://avatars.discourse-cdn.com/v4/letter/g/9de053/32.png) [@Gfactor](https://boards.straightdope.com/u/Gfactor)\ **Post date:** [October 25, 2007, 5:59pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/33 "2007-10-25T17:59:40Z")
FWIW: > [@](#): > > Cooking with cast iron actually adds iron to your diet, as much as 3 milligrams for every 3 ounces of food cooked. The more acidic the food you cook, the more iron is leached from the pan. Iron is critical to human health, especially that of women and infants. [http://www.wholefoodsmarket.com/recipes/kitchentips/castironcookery.html](http://www.wholefoodsmarket.com/recipes/kitchentips/castironcookery.html) > [@](#): > > Children may show signs of toxicity with ingestions of 10-20 mg/kg of elemental iron. Serious toxicity is likely with ingestions of more than 60 mg/kg. Iron exerts both local and systemic effects and is corrosive to the GI mucosa and can affect the heart, lungs, and liver. Excess free iron is a mitochondrial toxin that leads to derangements in energy metabolism. Although iron poisoning is a clinical diagnosis, serum iron levels are useful in predicting the clinical course of the patient. In treatment of iron poisoning, consider both bowel decontamination with whole bowel irrigation and chelation using intravenous administration of deferoxamine. > **[Pediatric Iron Toxicity: Practice Essentials, Pathophysiology, Etiology](https://emedicine.medscape.com/article/1011689-overview)** > > Iron poisoning is a common toxicologic emergency in young children. Contributing factors include the availability of iron tablets and their candylike appearance. > [@](#): > > The lethal dose of iron for a 2 year old child is 3 g, and 1 g leads to severe poisoning. [Plants Poisonous to Livestock - Cornell University Department of Animal Science](http://www.ansci.cornell.edu/plants/toxicagents/iron.html) > [@](#): > > It is possible to consume too much iron. Toxicity levels begin at about 45 milligrams per day. On an average diet it is highly unlikely that cooking with cast iron will bring a person to this level. [http://www.holidaycook.com/cast-iron/health-benefits.shtml](http://www.holidaycook.com/cast-iron/health-benefits.shtml) But: > [@](#): > > Iron poisoning can occur if children consume adult doses of iron supplements, and toxicity has even been known to occur from cooking in cast iron pans. > **[emsresponder.com domain is for sale | Buy with Epik.com](https://emsresponder.com/features/article.jsp?id=3688&siteSection=16)** > > emsresponder.com - Make an Offer if you want to buy this domain. Your purchase is secured by Epik. _and see_ [Take care if using iron skillet for baby food](http://sustainableag.osu.edu/~news/files/chowironbaby.pdf) (pdf): > [@](#): > > the iron content in apple sauce, an acidic food, increases from 0.26 milligrams in 100 grams (about 3.5 ounces) to 6.26 milligrams. Other foods could be less or more, depending on the food. There aren’t any handy charts to consult to know exactly. > You do want to make sure your child gets enough iron — iron deficiency in very young children can cause problems in both normal physical activity and normal thinking and mental processing skills. But it’s also possible to get too much iron. The upper limit for iron for infants and children is 40 milligrams a day. So, if you do start using the iron skillet for heating baby food, be mindful of the amount of iron your baby consumes. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [October 25, 2007, 6:22pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/34 "2007-10-25T18:22:43Z")
[QUOTE=Tuckerfan] My understanding is that it can be a _slight_ danger in men, _unless_ they have a rare medical condition which causes the body to have too much iron in the blood. The treatment for this is frequent blood donations. [/QUOTE] Right. It is another good reason to give blood. Also dudes? If you are otherwise healthy but can not give blood, when you get a small cut- let it bleed a bit under clean running water, before you slather on polysporin and a bandage. ---
**Author:** ![1010011010](https://avatars.discourse-cdn.com/v4/letter/1/ea666f/32.png) [@1010011010](https://boards.straightdope.com/u/1010011010)\ **Post date:** [October 25, 2007, 8:27pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/35 "2007-10-25T20:27:52Z")
[QUOTE=Mangetout] Wouldn’t it just look ‘glowy’? [/QUOTE] I’m just relaying how it was described. Might be that _everything_ is “glowy” with internal heat (including cold things) but hot things are fuzzier. If everything has an IR halo, you wouldn’t know to describe it as anything special or different between hot and cold. Or it could have something to do with the scattering of IR light. Or it could just be a quirk of how it was processed in the visual cortex. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 25, 2007, 8:58pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/36 "2007-10-25T20:58:58Z")
> [@](#): > > Oh, and they hurt like heck if you’re knocked in the head with them. Skillets don’t kill people. Angry housewives kill people. And the excessive-iron-uptake condition mentioned above is called hemochromatosis, and it’s actually one of the most common heriditary disorders in the US, at about 1 case per 200 people (coincidentally, I just learned yesterday that I’m one of those cases). Decide for yourself whether that counts as “rare”. ---
**Author:** ![chorpler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chorpler/32/2888_2.png) [@chorpler](https://boards.straightdope.com/u/chorpler)\ **Post date:** [October 26, 2007, 3:03pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/37 "2007-10-26T15:03:45Z")
[QUOTE=1010011010] I’m just relaying how it was described. Might be that _everything_ is “glowy” with internal heat (including cold things) but hot things are fuzzier. If everything has an IR halo, you wouldn’t know to describe it as anything special or different between hot and cold. Or it could have something to do with the scattering of IR light. Or it could just be a quirk of how it was processed in the visual cortex. [/QUOTE] OK, I’m curious – described by who? Somebody who can see near-IR with their eyes? Or somebody wearing night vision goggles or something? ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [October 26, 2007, 5:54pm UTC](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825/38 "2007-10-26T17:54:08Z")
[QUOTE=chorpler] OK, I’m curious – described by who? Somebody who can see near-IR with their eyes? [/quote] They’re probably seeing the shimmering air above it. [Previous page](https://boards.straightdope.com/t/safety-of-cast-iron-cookware/423825.md?page=1)