Analysis
HTS 3507.90.20 covers pencillin G amidase under heading 3507 (enzymes; prepared enzymes not elsewhere specified or included).
Goods classified here enter the United States duty-free at the general (normal trade relations) rate, as do about 50% of the 14 tariff lines in chapter 35. Free here means free of the base duty only: origin-specific Chapter 99 duties such as Section 301 can still be owed.
Goods from countries without normal trade relations pay the column 2 rate of 25% instead of nothing, so origin decides between free entry and a 25% duty.
The other lines in the same group are 3507.10.00 (rennet and concentrates thereof, duty-free) and 3507.90.70 (other: other, duty-free).
Census statistics map these goods to NAICS 325199 (All Other Basic Organic Chemical Manufacturing), an industry of 894 US establishments employing 77,304 people. That is the industry code a US manufacturer of the same product would normally use.
All 2 neighbouring lines carry the same duty-free rate, so a borderline choice between them changes the statistics reported, not the duty paid.
Neighbouring lines
| Line | Description | General rate |
|---|---|---|
| 3507.10.00 | Rennet and concentrates thereof | Free |
| 3507.90.70 | Other: other | Free |