49 CFR 174.680: Division 6.1 (poisonous) materials with foodstuffs.

(a) Except as provided in paragraph (b) of this section, a carrier may not transport any package bearing a POISON or POISON INHALATION HAZARD label in the same car with any material marked as, or known to be, a foodstuff, feed or any other edible material intended for consumption by humans or animals.

(b) A carrier must separate any package bearing a POISON label displaying the text “PG III,” or bearing a “PG III” mark adjacent to the POISON label, from materials marked as or known to be foodstuffs, feed or any other edible materials intended for consumption by humans or animals, as required in § 174.81(e)(3) for classes identified with the letter “O” in the Segregation Table for Hazardous Materials.