Harmonized Tariff Classification is based upon the guidance from the World Customs Organization
(WCO) for 180 countries representing more than 98 per cent of all international trade. Goods are
classified using a 6-digit portion that is harmonized across all members plus a variable number of
additional digits that are country-specific. Chemicals are classified in a variety of chapter headings,
but are found primarily in Chapters 28 and 29.

Links for the HS classifications for various countries are shown below:
- US – import https://hts.usitc.gov/current
- US – export (Schedule B) https://census.gov/foreign-trade/schedules/b/index.html
- EU – import http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L:2016:294:FULL&from=EN
- CAN – import http://www.cbsa-asfc.gc.ca/trade-commerce/tariff-tarif/
- JAPAN – import http://www.customs.go.jp/english/tariff/