8506.30 - Mercuric oxide:

This HTS classification, 8506.30, specifically covers primary cells and primary batteries utilizing mercuric oxide as a key component. These are electrochemical devices that convert chemical energy into electrical energy and are not designed to be recharged. The presence of mercuric oxide distinguishes these batteries from other primary battery types.

In contrast to its sibling categories, 8506.30 focuses exclusively on the chemical composition of the cathode material. For example, 8506.10.00 pertains to batteries using manganese dioxide, while 8506.40 relates to those employing silver oxide. Similarly, 8506.50.00 and 8506.60.00 differentiate based on lithium and air-zinc chemistries, respectively. All these categories fall under the broader heading of primary cells and batteries, but the specific chemical active material is the determinant for classification at this level.

The subcategories within 8506.30 further refine the classification based on physical characteristics. 8506.30.10.00 is designated for mercuric oxide batteries with an external volume not exceeding 300 cubic centimeters. This typically encompasses smaller, more compact battery types. The residual category, 8506.30.50.00, covers all other mercuric oxide primary cells and batteries that do not meet the volume criteria of the preceding subheading, allowing for the classification of larger or irregularly shaped units.