Analysis
HTS 2808.00.00 covers nitric acid; sulfonitric acids under heading 2808 (nitric acid; sulfonitric acids). US Customs collects import statistics for it under 2 ten-digit suffixes, reported in kilograms.
For statistics it divides in two: 2808.00.00.10 for nitric acid and 2808.00.00.20 for sulfonitric acids. Both pay the same duty; the suffix records which kind was imported.
The normal trade relations rate here is zero, shared by about 29% of the 274 tariff lines in chapter 28, a useful check when a neighbouring dutiable line is a candidate. Chapter 99 measures such as Section 301 or 232 can still apply on top, depending on where the goods come from.
It is the only US line under subheading 2808.00, so the six-digit code used by every Harmonized System country and the eight-digit US line describe the same goods; a foreign tariff or an exporter's invoice showing 2808.00 points straight here.
Census statistics map these goods to NAICS 325311 (Nitrogenous Fertilizer Manufacturing), an industry of 194 US establishments employing 7,033 people. That concordance is how imports of this line are compared with US output.