Q & A: Lead in Aluminium Cookware (2024)

Q & A: Leadin Aluminium Cookware

Original question sent in by GeorgeChapman, USA. Answers prepared by Swetha Lingala (The LEAD Group's Researcher)& Elizabeth O'Brien

George: "Is the lead (Pb) contentof the common US aluminium alloy 6061 responsible for the perceived aluminium -Alzheimer's link? Apparently aluminium is readily filtered out of the body whereas lead (Pb) is retained in the body.

Lead (Pb) adds some beneficial materialproperty to the 6061 aluminium alloy. Could the small amount of consumed lead(Pb), leached out from the 6061 aluminium alloy commonly used to manufacturesoda cans, cooking ware, etc.. , accumulate over decades in the body and causeappreciable health problems? If so why do we not hear more about this lead (Pb)problem?"

Swetha: "Hi George,

Thank you for your fascinatingemailabout 6061 Aluminium alloy containing lead(Pb). Even our lead expert, ElizabethO'Brienwas not aware of it.

I found the following confirmation thatlead can be added to Aluminium Alloys:

''Lead (Pb) and Bismuth (Bi) –Leadand bismuth are added to aluminium to assist in chip formation and improvemachinability. These free machining alloys are often not weldable because thelead and bismuth produce low melting constituents and can produce poormechanical properties and/or high crack sensitivity on solidification."

[http://www.esabna.com/us/en/education/blog/how-and-why-alloying-elements-are-added-to-aluminum.cfm]

The following article implies that 6061Aluminium Alloy contains lead:

"In 1990, the development effortsat ALCOA's Massena Operations began with the objective to create a freemachining alloy that would be comparable to a lead bearing alloy, 6262, instrength, machinability, corrosion resistance, anodizing, brazing, and weldingresponses while eliminating the health and environmental concerns associatedwith lead."

".....Proclaimed as the fastestgrowing new product in automotive and miscellaneous applications the full coldfinished product line in T8, T9 and T651 tempers excel in markets where 6262,6061, 2011 aluminium alloys and 12L14 steels are used today."

[http://papers.sae.org/980459/]

The Following article doesn't indicatethat 6061 Aluminium Alloy contains lead but shows the presence of lead andbismuth in some Aluminium Alloys:

"Lead.Normally present onlyas a trace element in commercial-purity aluminium, lead is added at about the0.5% level with the same amount as bismuth in some alloys (2011 and 6262) toimprove machinability."

[http://www.keytometals.com/Article55.htm]

The following table shows that Lead (andany other element not specified separately) is limited in 6061 Aluminium Alloyto 0.05%, but unfortunately the table is not referenced:

[http://en.wikipedia.org/wiki/Aluminium_alloy]

The Following article shows that 6061Aluminium Alloy does not contain lead (Pb):

In 1988, Luxfer switched to a"6061" alloy, which does not contain lead.

[http://www.scubadiving.com/gear/accessories/consumers-guide-scuba-tanks]

Could you please provide referenceswhich state the actual level of lead found in 6061 Aluminium Alloy?

George: "Yes my mistake it's not6061. Here's the list of Aluminum alloys I found earlier on line (www.aluminum.org/sites/default/files/Teal_Sheets.pdf).

In the past what alloy did they makecookware out of? You can see many alloys with Pb as a constituent.

I'm sure things have changed now,perhaps this generation of Alzheimer sufferers were exposed to decades ofaluminium alloys containing lead.

Thanks for the response & articles,

George:

Elizabeth: "You raise some veryimportant questions and sadly my volunteer researcher has been unable to comeinto work for several weeks due to lack of a baby sitter

And today when she (Swetha) did come in,she only had time to put together the following info, which doesn't go all theway to answering the question as to whether the aluminium/aluminium cookware weall used in decades gone by, and which is likely still being used widely in manycountries, contains lead. There's possibly a different answer in every country.Well worth finding out though.

Cheers,

Elizabeth O'Brien"

Swetha:

http://is.gd/XYEcMd

"The conventional aluminiumcookware is usually made from a single layer of aluminium alloy which may beanodized on the outside surface and given a non-stick surface on the inside,cooking surface. Oftentimes such cookware is made from 3003 Aluminium alloy or alike aluminium alloy which offers higher strength than purer aluminium such as1100 aluminium."

http://www.azom.com/article.aspx?ArticleID=6618

"The Aluminium / Aluminium 3003alloy is used in ductwork, chemical equipment, and general sheet metal work. Itis also used in manufacturing the following items:

• Cooking utensils
• Builder's hardware
• Pressure vessels
• Ice cube trays"

George: "Hi Swetha,

Thank you so much for looking into thisand providing interesting links. I'll have to look into the aluminium hydroxideformation and toxicity. It would be interesting to see if some of thedetrimental effects blamed on aluminium can be linked to lead or other knowntoxic alloy additives. Perhaps we can find a healthy metal for cooking - so farit sounds like surgical stainless steel is the best.

Thanks again for following up on this.

George Chapman"

Swetha: "Hi George,

Regarding recommended cookware metals,in the book "Clean, Green and Lean: Get rid of the toxins that make you fat- Drop the weight in 30 days." Author Dr Walter Crinnion, ND, writes:

'Cookware. Get rid of chemical-spewingnon-stick pans. Ceramic titanium and porcelain-enamelled cast iron are greatalternatives.' (Page 141)

But because iron deficiency isassociated with increased lead absorption from the gut, and because enamelglazes on cast iron eliminate the possibility of adding iron to the food duringcooking, the following recommendation on the best cookware metal could actuallybe more lead-safe:

“Cast iron cookware. Cast iron isknown for its durability and even heat distribution. Unglazed cast iron cantransfer notable amounts of iron into food, but unlike the metals that come offother types of pots and pans, iron is considered a healthy food additive by theU.S. Food and Drug Administration.”

(http://www.mnn.com/food/healthy-eating/questions/whats-the-safest-cookware)

It is also apparent from the followingthat cast iron cookware (without any coating/glaze) is recommended wheneverreducing lead exposure is the aim:

For vegetarians or vegans a goodsupplementation technique is through cooking acidic vegetables (such as tomatoesor cabbage) in non enamelled cast iron pots which has been consistently shown tosignificantly increase dietary iron (165,60,166,167); a technique that worksequally well for non-vegetarians and which may be preferable to ironsupplementation in pill form. For this purpose it should be noted that materialsdo not have to be naturally high in iron to improve iron status (168). Shouldthere be difficulty in finding non-enamelled cast iron cookware Lodge Cast IronCookware of Tennessee provides a range that is widely distributed. Note that theiron in many vegetables is more bioavailable (capable of being absorbed) whencooked rather than raw (341).

Iron cooking vessels: The followingitems have their iron content more than doubled when cooked in iron containerwithout a protective surface. Rear Row: red cabbage, tomato, rice, corn mealFront Row: tomatoes, capsicum (bell or banana peppers in USA), pureedvegetables, wild rice, apple sauce, scrambled egg, corn meal, Foreground:scrambled egg Not pictured: milk

(https://lead.org.au/lanv9n3/Iron_Nutrition_and_Lead_Toxicity_Short.pdf- page 6)

So, despite the comment made about theiron of cast iron cooking pots not being absorbed (in the article I previouslysent you, at http://www.happycookingco.com/hidden-dangers.cfm) I find the information above on our own website to be better-referenced.

Returning to my search for the answersto the questions your emails raise...

1. Which Aluminium Alloys were used inUnited States in the past to make cooking pots?

Below URL shows 3000 series and 8000series Aluminium Alloys ARE used in making cookware:

http://www.meyer-mab.com/technical-information/

Specifically, the above URL states:

“3XXX Series - Due to its excellentformability, 3003 has a wide range of uses including cookware.The addition ofMagnesium gives it [3004] strengths approaching 5052 along with great corrosionresistance and good formability. These properties make 3004 a good candidate forstorage tanks, pressure vessels and cookware.“

“8XXX Series - This series comprisesalloys that use less common elements, including Tin, Iron, Nickel and Lithium.The Lithium alloys are attractive for some aerospace applications due to theirvery light weight, high strength and increased ability to stretch withoutbreaking. Other uses for 8XXX alloys include cookware, conductor material, andsome high temperature applications.”

Next time I am in the office I’llsearch for whether the above-mentioned 3003, 3004 and 8000 series aluminiumalloys contain any lead.

Skipping ahead to Q. 5 (Are there anylead containing Aluminium Alloys still used anywhere in the world to makecooking pots?), I have found the following three related articles about scrapmetal being used to make aluminium pots in Cameroon, which release hundreds oftimes the Californian daily lead limit from consumer products, into the food. Iam wondering what inspired your original question? Was it any of these articles(or another article about this Cameroon study):

http://www.voanews.com/content/africa-aluminum-cookware-15aug14/2414509.html;

http://www.sciencedaily.com/releases/2014/08/140812122325.htm;

http://www.sciencedirect.com/science/article/pii/S0048969714010316
[please find this last one attached as Weidenhame et al Lead exposure fromaluminium cookware in Cameroon 20141015 FULL.pdf]

I hope that aluminium alloys forcookware were never made so carelessly from lead-containing scrap metal in thedeveloped world, as the above articles report is occurring now in Cameroon andprobably the rest of Africa as well as in Bangladesh and Thailand and possiblythe rest of Asia, but I’ll keep researching just in case... until nextweek....

Kind regards

Swetha Lingala (with help from ElizabethO’Brien)"

Swetha: "Hi George,

2. Do those Aluminium Alloys (3003,3004, 8000) contain Lead?

As per my research the URL shown belowshows these is no presence of Lead (Pb) in the above mentioned Aluminium Alloys.

http://www.suppliersonline.com/propertypages/3003.asp

http://www.suppliersonline.com/propertypages/3004.asp

Next time I am in the office I’llsearch for whether the 8000 series aluminium alloys contain any lead.

Thanks

Swetha Lingala"

Swetha: "Hi George,

I am still searching the internet toanswer the following Questions:

Which Aluminium Alloys were used inUnited States in past to make cooking parts?

Do those Aluminium Alloys contain Lead?

If so, how much lead?"

Swetha: "Hi George,

As there is no presence of Lead in UScookware made of Aluminium Alloys (3003, 3004, 8000 series), it gives answers tothe remaining 3rd and 4th Questions.

3) If so, how much lead?

4) Are there any lead containingAluminium Alloys still used in US to make cooking pots?

Regarding Question 5:

5) Are there any lead containingAluminium Alloys still usedanywhere in the world to make cooking pots?

A) As per my research the Africancountries and probably other under-developed countries are still using andmaking aluminium cooking utensils using scrap metal and thus the cookware cancontain Lead.

For your ref:

http://www.voanews.com/content/africa-aluminum-cookware-15aug14/2414509.html

http://www.sciencedaily.com/releases/2014/08/140812122325.htm"

I realise that the following quotesdon't answer any of the above Questions, but I think you will find theinformation very interesting nevertheless.

Very soft metal. Extreme chemicalreaction between food and pan. "All Vegetables cooked in Aluminium producehydroxide poison which neutralizes digestive juices, producing stomach andgastrointestinal trouble, such as stomach ulcers and colitis." Dr. A.McGuigan's Report on Findings for the Federal Trade Comm. In Docet Case No. 540Washington, D.C. Note: The sale of aluminium cookware is prohibited in Germany,France, Belgium, Gr. Britain, Switzerland, Hungary and Brazil.

Glass / Enamel Coated

Poor heat distribution. Foods stick andburn. Contains lead. Lead can cause reproductive harm and learning disabilities.[ http://www.happycookingco.com/hidden-dangers.cfm]

Interestingly also, the followingwebsite lists stainless steel alloys, some of which contain lead:

http://www.yamco-yamashin.com/en/products/guide_stainless_steel.html

So that might be more research foranother day, to work out if stainless steel cookware contains lead.

In trying to answer the above questions,today I located the following information:-

1. "The 3000 series is made up ofalloys of aluminium and manganese.These alloys are not as strong as the2000 series, but they also have good machinability. Alloys in this series areused for cooking utensils; storage tanks; aluminium furniture; highway signs androofing." [http://www.chemistryexplained.com/elements/A-C/Aluminum.html]

I will be back next week to researchsome more."

George: "Swetha,

Thank you so much for looking into this!I guess lead alloys are not intentionally used in aluminium cookware, nor islead from cookware responsible for the Alzheimer/aluminium link.

I'll have to look into what it wouldtake to remove lead from scrap metal so it doesn't end up in cookware inCameroon. I would think something like spark gap spectrometry would be able toidentify lead in an aluminium alloy. The real key would be to sort it out beforeit gets mixed in with aluminium.

I'll have to look into how cookware ismade in Cameroon. Are there a few large metal smelting facilities, or do peoplemake there own cookware? If there are only a few smelters the lead wouldprobably be easier to sort out. If individuals are making their own cookware,one would have to go door to door offering to test & replace cookware.

Thanks again,

George Chapman"

Swetha: "George,

Your thoughts are so interesting, I amCC'ing this to our colleagues who were responsible for the Research and Newsarticles about Leaded Aluminium pots in Cameroon.

Perhaps Jeffrey, Gilbert or Perry cansend us the original copy of the below URL as we have only the abstract of it.

http://www.sciencedirect.com/science/article/pii/S0048969714010316

Hopefully all the ideas in the articleand maybe George’s below can be incorporated into a Health programme for theaffected people, with articles in the media and social networks.

Thank you,

Yours Sincerely
Swetha Lingala
Researcher"

Jeff Weidenhamer, Ph. D.: "Swetha,

Thanks for your email. Our judgment isthat the lead in these aluminium alloys (not large amounts -- maximum 637 ppm byX-ray fluorescence) is picked up from the scrap materials used to make them.Please let me know if there are any other questions.

The paper is available through the OKInternational website at this address:

http://www.okinternational.org/docs/Final%20pb%20pots%20STOTEN%202014.pdf

In case you missed it, along the rightside of the science direct posting is a short video presentation about theresearch project:
http://www.sciencedirect.com/science/article/pii/S0048969714010316

Jeff Weidenhamer"