I know it's safe based on the formulation given to me over the phone. ACS grade Iodine 5%, ACS grade potassium Iodide 10%. The same formulation as the Lugol's solution made by Ricca Chemicals, which has been sold by jcrows.
Niles Bio is careful to say "not intended for human consumption" (which is not the same as "not safe for human consumption") because they are then less liable if somebody decides to drink the whole bottle and doesn't feel well.