870 - well yeah, ok. I don't mind telling you, you win.
What I meant is that such toxicity to be found in a used vinegar case wash is at such a low level and the amount involved is so tiny it is irrelivant, not that it is so totally pure and harmless we could drink five glasses full each day for five years without harm.
But, a vinegar brass wash is no where near as "toxic" as most things going down a drain is it? Things like phosphate deterigents and bleach, decayed meats and vegetable matter, toe nail clippings, the wash-out from a baby diapers and doggy baths, barfed-on linens from a sick room, etc, are much more toxic than trace elements of dreaded lead from primer flash.
In fact, the term "septic" itself says it's sorta toxic but we are safe if we don't drink it, okay? If it was beyond the capacity of sewers & septic tanks to handle such things we would have to purify our used water even before sending it down a drain.
Don't get too knotted up over paniced liberals shouting "the sky is falling" at the menton of trace amounts of lead returning to the ground from which it came. It is harmless when tiny amounts of such admittedly dastardly toxins are poured into a drain made for the purposes, and which itself often contains lead. Chill out man!