2845 - Isotopes other than those of heading 2844; compounds, inorganic or organic, of such isotopes, whether or not chemically defined:

Heading 2845 encompasses isotopes, excluding those falling under heading 2844 (which deals with radioactive elements and isotopes). This category specifically includes inorganic or organic compounds of these non-radioactive isotopes, irrespective of whether their chemical definition is established. The key distinguishing feature is the focus on isotopes other than those classified as radioactive.

When classifying within the HTS, it's crucial to differentiate heading 2845 from other chemical headings. Its primary distinction lies in its exclusive coverage of *non-radioactive* isotopes and their compounds. This contrasts with headings that might cover naturally occurring elements, isotopes with significant radioactive properties, or compounds where the isotopic composition is not the primary defining characteristic for classification.

Within heading 2845, further subdivisions are provided to classify specific types of enriched isotopes and their associated compounds. These subcategories, such as heavy water (deuterium oxide), boron enriched in boron-10, lithium enriched in lithium-6, and helium-3, allow for precise classification based on the specific isotope or isotopic enrichment. The residual category, "Other," captures any remaining compounds of non-radioactive isotopes not otherwise specified.