My ant poisons have been about 40% borax or boric acid (I'm moving to boric acid now), and 60% bait.
It looks like 10% boric acid is fine. Here is the formula from Patent 5939061:
2% to 5% Pectin by weight (to make this a gel)
.01% to 0.5% calcium salt (e.g. calcium carbonate, calcium chloride)
.001% to 10% toxicant (e.g. boric acid)
Dry attractant (20% to 40%) consisting of:
0.01% to 10% cellulose
1% to 10% sugar
0.5% to 5% plant starch (e.g. corn starch)
30% to 60% instant nonfat dry milk
20% to 60% dried egg yolk (where do I get THAT?)
0.0001% to 0.010% sterol compound
0.1% to 1% uric acid (makes ants think it is safe)
2% to 15% vegetable oil
Ultimately, about 20-40% protein, 20-40% fat, and 20-40% carb, with water to round it out (40% to 70%)
Personally, I think his use of percentages is totally wacky... but whatever makes him happy.
Apparently, different ants like different foods at different times of year, switching between carbs and proteins.