Hi!
Thank you for the reply. You seem to be confusing homeopathic Arsenicum Album 200c with Arsenic (which is, of course a poison). Here's a link which explains what the 200c means. http://homeopathyplus.com/tutorial-4-three-scales-of-potency/
I agree about the usefullness of hair tests though, I use them frequently in my practice. :-)