Hi all,

Ingest 5 mg of tin compounds?  Sounds like a piece of cake!! (so to speak)

Diet studies are notoriously difficult, but one I saw a while back said 
that the average UK resident ingested about 3 mg daily as part of the 
"normal" diet.  This is in the form of compounds inside canned foods (or 
maybe baking pan linings or large mixing bowls or nicely tinned pans, who 
knows).  So, allowing for diet changes since then, it is reasonable (in 
my opinion) to guesstimate that each of us consumes about half that 5 mg 
every day, anyhow.  Certain tin compounds are, in fact, allowable food 
additives on account of their color- and taste-preserving properties - 
see the US Code of Federal Regulations.

In fact, since this is a fantasy forum (or so I have read), let me 
subject you to my favorite tin chemical toxicity anecdote:

Back in the 1980's the good people at ITRI (Tin Research) found that tin 
chemicals were good fire-retardants (FRs) in a variety of materials.  Our 
branch office here in the US was part of the marketing effort, of course. 
 One of our primary concerns was potential toxicity (yes, even in the 
Reagan years), since that was/is questionable for the current FR 
chemicals.  We convinced the powers-that-be in Uxbridge to part with some 
funds to a local university to determine toxicity of the sodium and 
potassium stannates.  A rat feeding study was done and the surprising 
results will hearten all you rat-lovers out there, although dismay the 
SPCA on account of animal cruelty.  The preliminary round of testing 
produced no useful results, so the university people found they had to 
load up the rats with chemical, to the point that they reported the rats 
were sluggish from the sheer weight of their stomach contents.  But, upon 
dissection, there were still no toxic effects found.  So, they reported 
officially that the LD50 was greater than the highest level of feeding 
they used (they did not say much greater), and advised ITRI that it would 
be a waste of time and money (not to mention rats) to try any further 
toxicity studies on these chemicals.

I could go on longer, but this is enough.  And about Kay's motives, let's 
hear from all those out there with the lily-white hands.  Yes, go ahead 
and line up over there with all the professional environmental scientists 
that have contributed to these discussions, right beside those elusive 
OEMs.  (We all have our interests, don't we?  Even if it is only to keep 
blood pressure in check.)

Bill Hampshire
ex-Tin Research Institute, Inc.
now "independent"

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