John, that is an excellent lateral approach , one I wish I had thought of before ! I'll attempt to find out the answer to that, but if there is a qty limit (per week or day or whatever) then I'm sure to be under that with the tiny amount I generate. regards Peter On 31 January 2010 20:11, John Stockdale <j.sto@xxxxxxxxxxx> wrote: > Has the local government authority put a quantity limit in place? If not, > just dilute it to ensure that it's under 50ppm. > > john s > >