Total Hydrocarbon Content represents the percentage of polymer or polymers in the formulation. It is determined by subtracting the non-polymer constituents from 100%. In the reconstructed formulation, ARDL may have made other minor corrections due to sulfur containing accelerators, the presence of certain non-extractable resins, polymeric fiber content, sulfur levels in carbon black, or when certain polymers are ashed at high temperatures that may generate a small amount of soot, measured as carbon black. From past experience and performing chemical analyses on hundreds of controls, the small adjustments that ARDL makes more accurately describe the formulation as compounded and account for minor abnormalities in test results related to certain polymers, not accounted for in ASTM test specifications.
ASTM D297, Item 11