Section 1090.320 - 500 ppm LM diesel fuel standards(a)Overview. 500 ppm LM diesel fuel produced or distributed by a transmix processor or pipeline operator under § 1090.515 must meet the per-gallon standards of this section.(b)Sulfur standard. Maximum sulfur content of 500 ppm.(c)Cetane index or aromatic content. The standard for cetane index or aromatic content in § 1090.305(c) .