Stop sell orders have been placed on commercial coolants due to regulatory findings that concentrations of denatonium benzoate (DNB) are too low. Issues with ASTM D7304 have been debated and an improved method proposed. The new method is now in the process of interlaboratory study (ILS) and ballot.
Keywordsanalytical method; antifreeze; Bitterant; chromatography; denatonium ion; denatonium benzoate; engine coolant; HPLC;
Edward Eaton, Sr.
Ballot Item Approved as D7304-2014 and Pending Publication