Q & A: Lead
in Aluminium Cookware
Original question sent in by George
Chapman, USA. Answers prepared by Swetha Lingala (The LEAD Group's Researcher)
& Elizabeth O'Brien
George: "Is the lead (Pb) content
of the common US aluminium alloy 6061 responsible for the perceived aluminium -
Alzheimer's link? Apparently aluminium is readily filtered out of the body where
as lead (Pb) is retained in the body.
Lead (Pb) adds some beneficial material
property to the 6061 aluminium alloy. Could the small amount of consumed lead
(Pb), leached out from the 6061 aluminium alloy commonly used to manufacture
soda cans, cooking ware, etc.. , accumulate over decades in the body and cause
appreciable health problems? If so why do we not hear more about this lead (Pb)
Swetha: "Hi George,
Thank you for your fascinating email
about 6061 Aluminium alloy containing lead(Pb). Even our lead expert, Elizabeth
O'Brien was not aware of it.
I found the following confirmation that
lead can be added to Aluminium Alloys:
''Lead (Pb) and Bismuth (Bi) – Lead
and bismuth are added to aluminium to assist in chip formation and improve
machinability. These free machining alloys are often not weldable because the
lead and bismuth produce low melting constituents and can produce poor
mechanical properties and/or high crack sensitivity on solidification."
The following article implies that 6061
Aluminium Alloy contains lead:
"In 1990, the development efforts
at ALCOA's Massena Operations began with the objective to create a free
machining alloy that would be comparable to a lead bearing alloy, 6262, in
strength, machinability, corrosion resistance, anodizing, brazing, and welding
responses while eliminating the health and environmental concerns associated
with lead. "
".....Proclaimed as the fastest
growing new product in automotive and miscellaneous applications the full cold
finished product line in T8, T9 and T651 tempers excel in markets where 6262,
6061, 2011 aluminium alloys and 12L14 steels are used today."
The Following article doesn't indicate
that 6061 Aluminium Alloy contains lead but shows the presence of lead and
bismuth in some Aluminium Alloys:
"Lead. Normally present only
as a trace element in commercial-purity aluminium, lead is added at about the
0.5% level with the same amount as bismuth in some alloys (2011 and 6262) to
The following table shows that Lead (and
any other element not specified separately) is limited in 6061 Aluminium Alloy
to 0.05%, but unfortunately the table is not referenced:
aluminium alloy composition limits (% weight)
The Following article shows that 6061
Aluminium Alloy does not contain lead (Pb):
In 1988, Luxfer switched to a
"6061" alloy, which does not contain lead.
Could you please provide references
which state the actual level of lead found in 6061 Aluminium Alloy?
George: "Yes my mistake it's not
6061. 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 make
cookware 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 of
aluminium alloys containing lead.
Thanks for the response & articles,
Elizabeth: "You raise some very
important questions and sadly my volunteer researcher has been unable to come
into 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 the
way to answering the question as to whether the aluminium/aluminium cookware we
all used in decades gone by, and which is likely still being used widely in many
countries, contains lead. There's possibly a different answer in every country.
Well worth finding out though.
"The conventional aluminium
cookware is usually made from a single layer of aluminium alloy which may be
anodized 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 a
like aluminium alloy which offers higher strength than purer aluminium such as
"The Aluminium / Aluminium 3003
alloy is used in ductwork, chemical equipment, and general sheet metal work. It
is also used in manufacturing the following items:
Ice cube trays"
George: "Hi Swetha,
Thank you so much for looking into this
and providing interesting links. I'll have to look into the aluminium hydroxide
formation and toxicity. It would be interesting to see if some of the
detrimental effects blamed on aluminium can be linked to lead or other known
toxic alloy additives. Perhaps we can find a healthy metal for cooking - so far
it sounds like surgical stainless steel is the best.
Thanks again for following up on this.
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-spewing
non-stick pans. Ceramic titanium and porcelain-enamelled cast iron are great
alternatives.' (Page 141)
But because iron deficiency is
associated with increased lead absorption from the gut, and because enamel
glazes on cast iron eliminate the possibility of adding iron to the food during
cooking, the following recommendation on the best cookware metal could actually
be more lead-safe:
“Cast iron cookware. Cast iron is
known for its durability and even heat distribution. Unglazed cast iron can
transfer notable amounts of iron into food, but unlike the metals that come off
other types of pots and pans, iron is considered a healthy food additive by the
U.S. Food and Drug Administration.”
It is also apparent from the following
that cast iron cookware (without any coating/glaze) is recommended whenever
reducing lead exposure is the aim:
For vegetarians or vegans a good
supplementation technique is through cooking acidic vegetables (such as tomatoes
or cabbage) in non enamelled cast iron pots which has been consistently shown to
significantly increase dietary iron (165,60,166,167); a technique that works
equally well for non-vegetarians and which may be preferable to iron
supplementation in pill form. For this purpose it should be noted that materials
do not have to be naturally high in iron to improve iron status (168). Should
there be difficulty in finding non-enamelled cast iron cookware Lodge Cast Iron
Cookware of Tennessee provides a range that is widely distributed. Note that the
iron in many vegetables is more bioavailable (capable of being absorbed) when
cooked rather than raw (341).
Iron cooking vessels: The following
items have their iron content more than doubled when cooked in iron container
without a protective surface. Rear Row: red cabbage, tomato, rice, corn meal
Front Row: tomatoes, capsicum (bell or banana peppers in USA), pureed
vegetables, wild rice, apple sauce, scrambled egg, corn meal, Foreground:
scrambled egg Not pictured: milk
- page 6)
So, despite the comment made about the
iron of cast iron cooking pots not being absorbed (in the article I previously
sent 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 answers
to the questions your emails raise...
1. Which Aluminium Alloys were used in
United States in the past to make cooking pots?
Below URL shows 3000 series and 8000
series Aluminium Alloys ARE used in making cookware:
Specifically, the above URL states:
“3XXX Series - Due to its excellent
formability, 3003 has a wide range of uses including cookware.The addition of
Magnesium gives it  strengths approaching 5052 along with great corrosion
resistance and good formability. These properties make 3004 a good candidate for
storage tanks, pressure vessels and cookware.“
“8XXX Series - This series comprises
alloys that use less common elements, including Tin, Iron, Nickel and Lithium.
The Lithium alloys are attractive for some aerospace applications due to their
very light weight, high strength and increased ability to stretch without
breaking. Other uses for 8XXX alloys include cookware, conductor material, and
some high temperature applications.”
Next time I am in the office I’ll
search for whether the above-mentioned 3003, 3004 and 8000 series aluminium
alloys contain any lead.
Skipping ahead to Q. 5 (Are there any
lead containing Aluminium Alloys still used anywhere in the world to make
cooking pots?), I have found the following three related articles about scrap
metal being used to make aluminium pots in Cameroon, which release hundreds of
times the Californian daily lead limit from consumer products, into the food. I
am wondering what inspired your original question? Was it any of these articles
(or another article about this Cameroon study):
[please find this last one attached as Weidenhame et al Lead exposure from
aluminium cookware in Cameroon 20141015 FULL.pdf]
I hope that aluminium alloys for
cookware were never made so carelessly from lead-containing scrap metal in the
developed world, as the above articles report is occurring now in Cameroon and
probably the rest of Africa as well as in Bangladesh and Thailand and possibly
the rest of Asia, but I’ll keep researching just in case... until next
Swetha Lingala (with help from Elizabeth
Swetha: "Hi George,
2. Do those Aluminium Alloys (3003,
3004, 8000) contain Lead?
As per my research the URL shown below
shows these is no presence of Lead (Pb) in the above mentioned Aluminium Alloys.
Next time I am in the office I’ll
search for whether the 8000 series aluminium alloys contain any lead.
Swetha: "Hi George,
I am still searching the internet to
answer the following Questions:
Which Aluminium Alloys were used in
United 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 US
cookware made of Aluminium Alloys (3003, 3004, 8000 series), it gives answers to
the remaining 3rd and 4th Questions.
3) If so, how much lead?
4) Are there any lead containing
Aluminium Alloys still used in US to make cooking pots?
Regarding Question 5:
5) Are there any lead containing
Aluminium Alloys still used anywhere in the world to make cooking pots?
A) As per my research the African
countries and probably other under-developed countries are still using and
making aluminium cooking utensils using scrap metal and thus the cookware can
For your ref:
I realise that the following quotes
don't answer any of the above Questions, but I think you will find the
information very interesting nevertheless.
Very soft metal. Extreme chemical
reaction between food and pan. "All Vegetables cooked in Aluminium produce
hydroxide poison which neutralizes digestive juices, producing stomach and
gastrointestinal trouble, such as stomach ulcers and colitis." Dr. A.
McGuigan's Report on Findings for the Federal Trade Comm. In Docet Case No. 540
Washington, 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 and
burn. Contains lead. Lead can cause reproductive harm and learning disabilities.
Interestingly also, the following
website lists stainless steel alloys, some of which contain lead:
So that might be more research for
another 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 of
alloys of aluminium and manganese. These alloys are not as strong as the
2000 series, but they also have good machinability. Alloys in this series are
used for cooking utensils; storage tanks; aluminium furniture; highway signs and
I will be back next week to research
Thank you so much for looking into this!
I guess lead alloys are not intentionally used in aluminium cookware, nor is
lead from cookware responsible for the Alzheimer/aluminium link.
I'll have to look into what it would
take to remove lead from scrap metal so it doesn't end up in cookware in
Cameroon. I would think something like spark gap spectrometry would be able to
identify lead in an aluminium alloy. The real key would be to sort it out before
it gets mixed in with aluminium.
I'll have to look into how cookware is
made in Cameroon. Are there a few large metal smelting facilities, or do people
make there own cookware? If there are only a few smelters the lead would
probably 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.
Your thoughts are so interesting, I am
CC'ing this to our colleagues who were responsible for the Research and News
articles about Leaded Aluminium pots in Cameroon.
Perhaps Jeffrey, Gilbert or Perry can
send us the original copy of the below URL as we have only the abstract of it.
Hopefully all the ideas in the article
and maybe George’s below can be incorporated into a Health programme for the
affected people, with articles in the media and social networks.
Jeff Weidenhamer, Ph. D.: "Swetha,
Thanks for your email. Our judgment is
that the lead in these aluminium alloys (not large amounts -- maximum 637 ppm by
X-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 OK
International website at this address:
In case you missed it, along the right
side of the science direct posting is a short video presentation about the