FEDERAL VIEWPOINT ON USE AND 

 POTENTIAL OF CHEMICAL OIL DISPERSANTS 



J. Steven Dorrler 



BACKGROUND 



Water-emulsif iable degreasers have been used since the early 1930s to 

 clean oily and greasy surfaces. The degreasers dissolved or dispersed in 

 grease or oil, making the resultant mixture dispersible in water so that it 

 could be flushed away with water. 



The early products were composed mostly of soaps and solvents. The 

 early products were of limited effectiveness to the petroleum shipping indus- 

 try, which needed products that could be used effectively aboard ship with 

 seawater. This need led to the use of materials other than soaps as emulsi- 

 fying agents because soaps break down in seawater. Sulfonated petroleum oils 

 and, later, more sophisticated synthetic detergents were used in these 

 products. 



Emulsifying degreasers were widely used aboard ship for engine room 

 maintenance, as well as for the cleanout of petroleum cargo tanks prior to 

 welding repairs and prior to upgrading of cargo. 



Because of their effectiveness in the cleanout of oil residues, degreas- 

 ers were also used to treat oil spills. In some cases, they were incorporated 

 in oil slops prior to their being dumped overboard to minimize formation. 



More than 200 products are commercially available for dispersing oil 

 from the surface of water. These products have been referred to as "soaps," 

 "detergents," "degreasers," "complexing agents," "emulsif iers," and "dispers- 

 ants." The last term describes best what this type of product is intended 

 to accompli sh--the dispersion of oil from the surface into and throughout 

 the body of water. Dispersant is therefore the preferred terminology. 



COMPOSITION 



The primary components of dispersants are surfactants, solvents, and 

 stabil izers. 



SURFACTANTS OR SURFACE-ACTING AGENTS (SAA) 



These are the major active components in dispersants. Through their 

 affinity for both oil and water, surfactants alter the interaction between 

 oil and water so that the oil tends to spread and can be more easily dispersed 

 into small globules--or what is commonly called an emulsion. 



Industrial Environmental Research Laboratory 

 U.S. Environmental Protection Agency 

 Edison, New Jersey 08817 



95 



