Commerce Misunderstanding How Isotopes Work, Ammonium Sulfate Importer Says

In a science-heavy motion for judgment filed Oct. 24, an importer of enriched isotope compounds said that the Commerce Department had, in a scope ruling, misunderstood the essential chemistry behind its products (Cambridge Isotope Laboratories v. U.S., CIT # 23-00080).

The department held that importer Cambridge Isotope Laboratories Inc.’s shipments of enriched ammonium sulfate would be subject to antidumping and countervailing duties on ammonium sulfate from China. But the ammonium sulfate isotope imported by Cambridge, (15N4)2SO4, is an entirely different product than the one covered by the orders, (NH4)2SO4 -- which has 14, not 15, nitrogen molecules.

15N nitrogen is extremely rare, accounting for only 0.37% of the nitrogen in the Earth’s atmosphere, Cambridge said. 14N makes up the rest of it, it said. To produce more 15N isotopes, it said, “the nitrogen must be specially processed.”

The orders expressly exclude Cambridge’s ammonium sulfate because they specifically refer only to the chemical compound (NH4)2SO4, the importer said. Its products and the products covered by the orders also have different weights and Chemical Abstracts Service numbers, it said. In other words, they’re two different products.

“A family of people often consists of related but not identical individuals,” Cambridge explained, citing the Department of Energy’s explanation of isotopes. “Elements have families as well, known as isotopes.”

The ammonium sulfate covered by the orders, (NH4)2SO4, is a fertilizer, it said; its ammonium sulfate, (15N4)2SO4, is used in laboratory research.

But Commerce found that Cambridge’s products were subject to the duties because the orders covered ammonium sulfate “in all physical forms.” In the ruling, Cambridge said, it held that the importer’s ammonium sulfate was just a physically enriched form of the compound described by the orders.

The department is required to read the language of scope rulings in the context of the industry they regard, however, Cambridge said. In this case, the “physical state” of a chemical compound refers to the compound’s state of matter -- solid, liquid or gas, it said.

“This makes sense as the Order should cover ammonium sulfate in its various possible physical states of being, such as a solid, a liquidate or a gas,” it said.

The order’s reference to “ammonium sulfate in all forms,” meanwhile, is explained in the International Trade Commission’s injury investigation report as “including mostly pellets and an aqueous form,” it said.

This case was stayed in November 2023 as Cambridge sought a partial revocation of the AD/CVD orders (see 2311020051). Cambridge filed for a changed circumstances review in April (see 2404110042).