Unless it is contaminated it doesn't seem to get much better than 99.9 % pure. 
 It is made from the inter part of trees left over from a sawmill cuttings and 
sawdust. They truck it into a to factory process it in to a solvent. The only 
contamination I can think of is if some cross contamination when processing, 
and 
that would carry whatever is mixed with it deep into tissue.  Thats what it 
does, goes deep into the tissue, used for many years as a muscle rub on Horses, 
and Livestock.  It is closely related to MSM  only one molecule apart.
 Tel Tofflemire
Dewey, AZ.




________________________________
From: "zzekel...@aol.com" <zzekel...@aol.com>
To: silver-list@eskimo.com
Sent: Sun, January 16, 2011 1:30:30 PM
Subject: Re: CS>DMSO

In a message dated 1/15/2011 2:42:12 P.M. Eastern Standard Time,  
blacksa...@comcast.net writes:
Does anyone know where you can    purchase 100% pharmaceutical grade DMSO (in 
glass bottles)?I’ve got    the industrial strength 99.9% pure from the local 
Agway store and I understand    it really shouldn’t be used due to the 
impurities. I’m in the Northeast so    would love to hear from everyone, but 
certainly northeastern places would help    with shipping costs.Thanks.Lisa
Hi Lisa, I've bought mine at the local farm supply for years & it works  great. 
Both internal & external..." If it's good enough for multi million  dollar race 
horses" it sure is good enough for my family--friends--pets--&  me...Lois