Is that 10-9? Or 10-12?
/johnny
10ug is 1/100,000th of a gram
1000 grams in a liter of water-based fluid, so 1 part in 100 million of the liquid, or 10 ppB!
That seems like an absurdly low limit. Arsenic can't possibly be that toxic, can it? Or is it cumulative and piles up in your body or something?