On 2005-12-14, Edwin Pawlowski > wrote:
>
> "Randall Nortman" > wrote in message
> nk.net...
>> This is something that's been bothering me for a while, but I can't
>> find much information about it. When (non-enameled) cast iron gets
>> seasoned, what exactly is happening chemically? What is that layer
>> you're depositing on the iron? It seems to me that you're essentially
>> burning oil and food particles onto the iron. Last time I checked,
>> burned, smoked oil is believed to be carcinogenic. The fumes from the
>> seasoning process certainly aren't very pleasant, and are presumably
>> carcinogenic. And yet, health authorities consistently recommend
>> cooking in cast iron as a way to increase dietary iron intake -- are
>> they simply overlooking the potential carcinogenic effects, or has it
>> been studied and found to be safe?
>
> Burning? Odors? You are doing something wrong if that is happening. Proper
> seasoning is when the heated oils polymerize. They change their physical
> state and seal the iron.

I have seen different advice on the proper temperature for seasoning.
Some sources say low temperatures of 300-350F, which would avoid
smoking with most oils. I found that to be less effective at creating
a nonstick surface than using a higher temperature, which causes some
smoking. Perhaps I should just stick (pun intended) with lower
temperatures? (I'm sure that time, the surface will still become more
nonstick with use.)


> POLYMERIZATION: a chemical reaction in which two or more molecules combine
> to form larger molecules that contain repeating structural units

That's a rather generic term. Many polymers are certainly
carcinogenic -- one type that might even be relevant in this context
would be the polycyclic aromatic hydrocarbons (PAHs), which have
received a lot of attention in the health press recently. (I'm not
entirely sure that PAHs would count as polymers, though.)


>> I'm not trying to be alarmist and tell people not to use cast iron.
>> I'm just curious and somewhat concerned.
>
> You seem to be very concerned about it though, and have no evidence to base
> anything about it. Borderline alarmist, IMO.

If I were being alarmist, I would have thrown out all my cast iron
(which I haven't), stormed into my neighbors' kitchens and thrown out
all their cast iron, and then posted to rec.food.equipment
(cross-posting to rec.food.cooking, sci.health.nuts, and alt.alarmism)
telling -- nay, commanding -- all of you good folks to throw out your
cast iron, and write your Congressperson to enact legislation to
create a Cast Iron Regulatory Oversight Council.

But I'm not telling anybody to do that. Instead, I posted a question,
admitting my ignorance about the subject and asking for information,
which I am grateful to have received in two separate responses. I am
indeed pleased that both responses seem to be saying very similar
things, and things which make sense to me, and do not cause me any
alarm.

--
Randall