Author Topic: Health considerations for soapstone?  (Read 3680 times)

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Offline steelsieve

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Health considerations for soapstone?
« on: August 28, 2010, 03:22:06 PM »
I found a local stone company specializing in kitchen countertops that sells soapstone remnants.  Other than ensuring that the stone is natural and unglazed, is there anything else I should be asking to make sure the stone is food safe prior to buying? 


Offline scott123

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Re: Health considerations for soapstone?
« Reply #1 on: August 29, 2010, 05:08:48 AM »
I've never seen glazed soapstone.  Due to it's inability to absorb liquids and soapy exterior, I don't think a glaze would stick to it.  The only thing that the countertop guys do with it is oil it with mineral oil- and they always oil it after the install, not before.  Even if you do get a piece that's been oiled, a light sanding will remove most of it, and what's left will burn away in the oven.

The biggest issue when purchasing soapstone isn't food readiness, but mis-identification. There's some varieties of soapstone (and other stones that are occasionally identified as soapstone) that aren't suitable for baking.

Your goal should be gray to lightish gray with whitish streaks. No other colors. No green, tan or ivory. The lighter gray/streakier the better, as the streaks are talc and talc is the basis for soapstone's superior conductivity. It's also vital that the stone feels soapy/silky.  Again- it's the talc that gives soapstone it's soapy feel.

Below is a photo of classic soapstone- the high talc variety.

Offline Bobino414

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Re: Health considerations for soapstone?
« Reply #2 on: August 29, 2010, 01:50:03 PM »

As Scott noted, the best soapstone for baking has a high percentage of talc.
Soapstone also has a Mohs rating of 1 (soft) as opposed to diamond rating 10.  Therefore you can scratch it with your fingernail.  So scratching soapstone can release talc powder into the air. 
If you inhale talc powder over a long period of time it can cause fibrosis of the lung; this reduces lung function.  I suppose if you use a wooden peel rather than a metal peel, you can eliminate scratching of the soapstone.  If you want to learn more about this, look up "pneumoconiosis."
Talc may also be ingested.  In its pure form this is not a problem as talc is found in pharmaceutical grade pills.  The only problem one may experience is if there is asbestosis mixed in.
 
IMO if you ate the whole stone in your oven, you are not at risk.

Another IMO: this is not an issue for your intended use.

Disclaimer:  "Ask your doctor or pharmacist."
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Bob

Offline scott123

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Re: Health considerations for soapstone?
« Reply #3 on: August 29, 2010, 02:28:40 PM »
As Scott noted, the best soapstone for baking has a high percentage of talc.
Soapstone also has a Mohs rating of 1 (soft) as opposed to diamond rating 10.  Therefore you can scratch it with your fingernail.  So scratching soapstone can release talc powder into the air. 
If you inhale talc powder over a long period of time it can cause fibrosis of the lung; this reduces lung function.  I suppose if you use a wooden peel rather than a metal peel, you can eliminate scratching of the soapstone.  If you want to learn more about this, look up "pneumoconiosis."

Bob, although soapstone for baking does have a lot of talc in it, it's usually distributed in such a way that the stone doesn't scratch easily.  You can scratch pure talc with your fingernail, but you can't do that with soapstone.  I've tried  :) Although I use a metal peel for retrieving the pie, I am careful not to scratch the stone.  I also, when I sand the stone (cheese spills), I use a wet sand technique so as not to kick up any talc into the air.

Offline Bobino414

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Re: Health considerations for soapstone?
« Reply #4 on: August 29, 2010, 02:41:37 PM »

Scott

I just visited my retired soapstone (until I can find someone to cut the thickness to 1.5 cm).
I can easily scratch it with my fingernail.  Maybe my stone has a higher percentage of  talc than yours.

Bob

Offline scott123

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Re: Health considerations for soapstone?
« Reply #5 on: August 29, 2010, 03:58:36 PM »
Scott

I just visited my retired soapstone (until I can find someone to cut the thickness to 1.5 cm).
I can easily scratch it with my fingernail.  Maybe my stone has a higher percentage of  talc than yours.

Bob

Hmmm... very interesting.  When you say 'scratch,' you mean make a mark, right, not necessarily gouge it, correct?

If it did have a higher percentage of talc, then it would pre-heat faster- which, I know from your posts, it didn't.  Dumb question, but you did remove your cordierite stone before putting the soapstone in, right?

Offline Bobino414

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Re: Health considerations for soapstone?
« Reply #6 on: August 29, 2010, 04:14:26 PM »

Scott

I scratched it with my thumbnail and got white powder underneath it.

From the top deck I removed my cordierite stone before inserting the soapstone, but I left the metal lath on the deck; this was put in by TAMPA Dave to give me a more uniform heat distribution. I left the lath and cordierite on the lower deck so I could do the stone warmup comparison. The thinner cordierite stones needed the lath as the heat distribution is now more uniform, maybe the thicker soapstone doesn't.

Bob

Offline scott123

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Re: Health considerations for soapstone?
« Reply #7 on: August 29, 2010, 04:26:44 PM »
Bob, there's burners under both decks, correct?

Offline Bobino414

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Re: Health considerations for soapstone?
« Reply #8 on: August 29, 2010, 04:34:34 PM »

Scott

There are three burners:  one on top deck-broilerlike.  The second under the top deck tray which also serves as broiler for second deck.  The third element is below the bottom tray.


 

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