acs

(ACS) - The ACS mark coupled with our Certified Analytical Reagent line indicates the reagent meets all of the specifications and requirements as found in the most recent edition and supplements of Reagent Chemicals, published by the American Chemical Society.


http://www.integrachem.com/grade.htm


NOTE:
To me this reads that the compound is guaranteed to have the chemical reaction one is looking for.
To me this whole thing reminds me of the recent Pet Food recall, where someone bought lower grade wheat gluten...