[Market-farming] asbestos in vermiculite

wiediger at msn.com wiediger at msn.com
Mon Feb 2 14:20:30 EST 2004

This asbestos in vermiculite reminds me of when I worked in the ceramic industry and OSHA tried to say there was asbestos in talc, all talc.  The Bureau of Mines recognized 2 forms of talc, one asbestos, one not.  

>From what I can read on this subject, vermiculite itself does not contain asbestos.  The public reports we are hearing about are talking specifically about vermiculite coming from a mine in Libby, Montana.  That geological formation did contain asbestos and that mine was closed around 1990.  Most of the vermiculite from that mine went into insulation, the kind blown into attics as loose fill and now floats around in the air.

But to be on the safe side, I think it would be prudent to wear a mask or face respirator when working with large quantities of soil less media.  I wouldn't doubt that one day we'll hear that inhaling peat causes farm workers to see Elvis in the convenient store.

If you do a Google search "asbestos contamination of vermiculite" or "vermiculite contaminated with asbestos", there is a lot of information out there.  Of course, who knows what you can or can't believe.

Paul Wiediger
Au Naturel Farm
  Subject: RE: [Market-farming] asbestos in vermiculite

  >Apparently the mineral
  >deposits that they use for making vermiculite naturally contain the mineral
  >asbestos.  The airborne small particles are the worst form of asbestos, as
  >compared to an encapsulated form. 

  Also (wearing my geologist's hat for just a bit) the word "asbestos" covers 
  several different minerals, some dangerous, some more benign. The ones that 
  cause cancer and silicosis, I believe, have fibers shaped like needles that 
  stick in your lungs.  Other "asbestos" minerals may be more platy, like 
  vermiculite also is. You can look at your vermiculite with a X10 hand lens, 
  or even your bare eyes, and see whether there are needles in it.  
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