The effectiveness of various strategies for oil spill response depends on the physical and chemical properties of the spilled oil in relation to the environmental conditions at the spill site. A large number of different types of crude oils and refined products are produced and transported through U.S. territorial waters. These crude oils and oil products all differ in the physical and chemical properties and these properties affect their rates of weathering in the environment. The changes in the physical and chemical properties of the oil have a direct bearing on oil recovery operations. They influence the selection of response methods and technologies applicable for cleanup, including their effectiveness and capacity, which can effect the time and cost of operations and the impacts on natural resources.

Before oil spill response plans are developed or approved, it is important to understand the chemistry and physical behavior of the spilled oil and how its characteristics change over time. Petroleum products (crude oils and fuels) vary in their volatility, flammability, water solubility, tendency to emulsify, viscosity and density. Some products are light, volatile, non-viscous, and highly flammable (e.g. gasoline), whereas others are heavy, non-volatile, viscous, and less flammable (e.g. heavy fuel oil). Spill response will differ depending on the oil type and its distinct characteristics. Safety concerns are greater for light, volatile flammable products than for heavier oils. The response preferences for flammable products are essentially to control the source and maintain a safe distance. As safety concerns diminish, the number and variety of preferred response actions increase. Knowledge of the ultimate fate and behavior of oil should drive countermeasure decisions.

1. Ensure that the physical and chemical properties of crude oil and refined products produced and transported through U.S. territorial waters are measured and included in an Internet accessible database. Properties to be measured include viscosity, density, specific gravity, solubility, flash point, pour point, distillation fractions, metal content, volatile organic compounds, interfacial tension and vapor pressure.
    
2. Ensure that the fate and behavior of crude oil and refined products produced and transported through U.S. territorial waters are measured and included in an Internet accessible database. Properties to be measured include evaporation, emulsion formation, chemical dispersibility, ignition temperature and adhesion.

1. Oils that are transported are often blends of different crude oils, and the relative proportions of component oils frequently change. Therefore the physical and chemical properties will vary. Similarly, the properties of crude oil taken from an individual well can vary with the depth of the well and the year of production. MMS will continue to measure the physical and chemical properties of crude oils (especially crudes from deepwater Gulf of Mexico and the Alaskan Beaufort Sea) and refined products that are produced and transported through U.S. territorial waters and include this new information in an Internet accessible database.
    
2. Continue to conduct research on the fate and behavior of crude oil and refined products that are produced and transported through U.S. territorial waters and include this new information in an Internet accessible database.
    
3. Investigate the fate and behavior of non-typical crude oils and refined products. Unlike most domestically produced crude oils, these oils rapidly form emulsions, surface skins or sink in a relatively short period of time. They persist as a result of their chemical properties and unusual behavior. Understanding the fate and behavior of these oils is crucial in developing improved response strategies.
    
4. Continue basic research on oil behavior mechanisms including weathering, evaporation, emulsification, dispersion, dissolution and photooxidation.
    
5. Take advantage of planned, experimental oil spills conducted outside of U.S. territorial waters to obtain information on the fate and behavior of oil for improving spill response operations.

For more information on the Properties and Behavior of Oil Projects, contact Joseph Mullin at 703-787-1556, or via email.