2710.20.10.25 - Containing more than 500 ppm of sulfur

This HTS classification, 2710.20.10.25, specifically designates fuel oils that are distillate or residual in nature, blended or otherwise. To fall under this category, the fuel oils must meet stringent testing criteria: they must have an A.P.I. gravity of 25 degrees or more, and exhibit a Saybolt Universal viscosity at 37.8°C ranging from 45 seconds to 125 seconds. This viscosity range is characteristic of what is commonly known as "No. 4-type fuel oils," indicating a specific density and flow property.

The primary distinguishing feature of this category, as indicated by its HTS code, is its sulfur content. Goods classified under 2710.20.10.25 are defined by containing "more than 500 ppm of sulfur." This contrasts directly with its sibling category, 2710.20.10.15, which covers fuel oils with a sulfur content of "not more than 500 ppm." Therefore, the precise sulfur concentration is the critical factor for differentiating between these two adjacent classifications.

As this is a leaf node within the HTS structure, there are no further subcategories to introduce. Classification at this level is complete, relying solely on the physical properties of A.P.I. gravity, Saybolt Universal viscosity, and the specific sulfur content to accurately categorize these fuel oils. The scope of this classification is firmly rooted within the broader context of petroleum-based distillate and residual fuel oils, as established by its parent categories.