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Petroleum Substances & Categories
The petroleum substances sponsored in the HPV Challenge Program are organized and evaluated according to product categories. The categories are typically organized around properties and refinery processes such as similar boiling ranges, similar process history, or similar end-uses.
Heavy Fuel Oils

The Heavy Fuel Oils Category includes 32 substances that are best described as a continuum of similar substances and the human health hazards of this category are associated with the presence of polycyclic aromatic compounds (PACs).  The environmental hazards of this category are determined by the carbon number distribution of the particular substance. This knowledge coupled with existing and new test data should satisfy all the HPV Challenge requirements for human health data in this Category.

The petroleum process streams are complex mixtures of hydrocarbons in the C7 –C50 range that boil between 121 and 600 °C; however, the more typical heavy fuel oils are mixtures of hydrocarbons in the C20 –C50 range. All of the category members are complex mixtures, containing variable amounts of alkanes, cycloalkanes, aromatics, olefins, asphaltenes and heteromolecules containing sulfur, oxygen, nitrogen and organometals. The residual fuels are low-grade fuels primarily used in industrial boilers and other directsource heating applications (e.g., blast furnaces) and as a fuel for large marine diesel engines. The finished heavy fuels (residual fuels) consist primarily of residuum of the refining process after virtually all of the higher-quality hydrocarbons have been removed from crude oil feedstock.  

Residual fuels are blended from a variety of different residual and distillate materials, and the exact blend for a specific residual fuel is determined largely by the desired viscosity of the finished fuel. To produce a residual fuel of a specified viscosity, the high viscosity of the residual streams is reduced by adding a diluent that is typically a lower quality distillate stream. As a result, the composition of residual fuel oils can vary widely and will depend on the refinery configuration, the crude oils being processed and the overall refinery demand. 

To meet the HPV Challenge, the Testing Group has thoroughly evaluated the substances within the Heavy Fuel Oils category and has made all of the reliable human health and ecological hazard data available to the public.

  • The Category Assessment Document (CAD) for Heavy Fuel Oils submitted to EPA by API which includes the final chemical hazard characterization and considers any new testing and analysis carried out for substances within the category.
  • The Robust Summary for Heavy Fuel Oils  submitted to EPA by the American Petroleum Institute (API) which summarizes the available reliable data on physic-chemical properties, environmental fate and transport pathways, ecotoxicity, and human health toxicity.
HPV Heavy Fuel Oils Studies
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