I've been cutting nacho triangles from rolled dough and then after lightly pan-roasting them I store them as ready-to-fry, which works and tastes very good but it devlops mould within a week. So, I purchased powdered Sodium Bemzoate, which should work considering the pH of my dough is slightly acidic, but I can't find reliable information about exact GMP limit.
I suspect it will depend a bit on where you live. However the limit in the USA is proscribed at 0.1% for foods, this is likely similar to the limits for most "western" countries.
This information was found by searching the FDA website for
"sodium benzoate" and is found in statute here