Technical grade. Analytical grade was more expensive. I don't expect the salesperson to be a PhD in chemistry, but telling her that it was for photographic use led to this grade.
Originally Posted by largeformat pat
Bacto will ask what your intended use is, too. Sodium thiosulphate being relatively benign meant that my intended use was satisfactory for the sale to proceed. She said that there were rigorous conditions for some of the more volatile products.
I can't see the connection between price and nefarious uses, fertiliser--as used by American terrorists--is pretty cheap.
Regards - Ross