9022.29.40.00 - Smoke detectors, ionization type

This HTS category, 9022.29.40.00, specifically classifies smoke detectors that operate on the principle of ionization. These devices utilize a small amount of radioactive material to ionize the air within a chamber. When smoke particles enter this chamber, they disrupt the flow of ions, triggering an alarm. This ionization type distinguishes them from other smoke detection technologies.

At this level of the tariff schedule, 9022.29.40.00 is distinguished from its sibling category, 9022.29.80.00, which is designated for "Other" apparatus utilizing alpha, beta, gamma, or other ionizing radiations for non-medical, non-surgical, non-dental, and non-veterinary uses. While both fall under the broader scope of ionizing radiation apparatus for non-medical applications, 9022.29.40.00 is reserved for the specific functionality of smoke detection via ionization, whereas 9022.29.80.00 would encompass other, less specifically defined ionizing radiation devices.

As this HTS code is a leaf node, there are no further subcategories to introduce. Classification under 9022.29.40.00 is therefore conclusive for ionization-type smoke detectors that do not fall under more specific headings or other general residual categories. The primary classification criteria revolve around the detection mechanism (ionization) and the intended function (smoke detection).