The Asphalts Category includes 6 substances that typically have a high boiling point,  high molecular weights, and high viscosity in order to meet the use specifications in commercial asphalt formulations. Asphaltic materials such as asphalt, oxidized asphalt, vacuum residuum, hydrodesulfurized vacuum residuum, decarbonized residuum and petroleum resins are all residual streams derived from the vacuum distillation of petroleum. Most of these streams are either sold as is, blended together, or subsequently processed (air blowing or solvent deasphalting) to produce a variety of end use asphalt products that achieve specific product performance specifications. 

The uses of asphalt create a dichotomous hazard profile between the ambient-temperature substances and the fumes generated from heated products. Toxicity and environmental fate of the ambient-temperature substances are defined by the refining step of vacuum distillation. Evaluation of their common physical-chemical properties is sufficient to satisfy HPV requirements for all substances in this category since exposures of both humans and the environment are predominantly to vapors from asphalt rather than to the asphalt itself. Toxicity and environmental fate of the fumes generated from heated in-use products are directly related to the temperature of fume generation.  

To meet the HPV Challenge, the Testing Group has thoroughly evaluated the substances within the Asphalts category and has made all of the reliable human health and ecological hazard data available to the public. The Asphalt Category for the HPV Challenge Program is aligned with the European Union’s substances category ―Bitumen (Asphalt) and Vacuum Residues. This allows harmonized efforts to collect and interpret data and potentially to harmonize risk assessments and risk management practices on petroleum products worldwide.

• The Category Assessment Document (CAD) for Asphalts 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 Data Matix (Appendix D) can be found here.

• The Robust Summary for Asphalts submitted to EPA by the American Petroleum Institute (API) which summarizes the available reliable data on physico-chemical properties, environmental fate and transport pathways, ecotoxicity, and human health toxicity.

• The EPA Screening-Level Hazard Characterization  for Asphalts which summarizes EPA’s views on the available data for the category and on the need for additional studies to fill data gaps.

• The API Petroleum HPV Testing Group’s Response  to the EPA Screening-Level Hazard Characterization for Asphalts.