I contacted Aaron industries (sold at Walmart), their H2O2 (Hydrogen-Peroxid) starts with Technical Grade in bulk (WITH stabilizers) and they add pure water to that. So, no, do not use this brand internally, it is not food grade.
Think about it, food grade is only about $50 gal with s/h, so why risk it with others just because it is .98 cents per quart? The 3% non-food grade equates to about the same price per gallon anyway, so you don't save anything, but add stabilizers to your already toxic body.
Even if you only wanted just a quart, isn't it worth the extra $49.02 to be safe and get the food grade? (and you have an extra 3 quarts for later)