OTTO FUEL II AND ITS COMPONENTS 5. POTENTIAL FOR HUMAN EXPOSURE 5.1 OVERVIEW Otto Fuel II is a mixture of three component chemicals, propylene glycol dinitrate, 2-nitrodiphenylamine, and dibutyl

Otto Fuel II is a mixture of three component chemicals, propylene glycol dinitrate, 2-nitrodiphenylamine, and dibutyl sebacate. Otto Fuel II enters the environment as these three components, which partition to the different environmental media according to their individual chemical and physical properties. Otto Fuel II is primarily released to water in waste streams from Navy facilities that produce it or are involved in torpedo rework operations. There is also a possibility that it could be spilled on soil during transfer operations. The limited data located on the environmental fate of Otto Fuel II components indicate that propylene glycol dinitrate is removed from water primarily by volatilization. Propylene glycol dinitrate is the most water soluble of the three components, although its solubility is low and it is not expected to persist in water for more than a few days. Neither 2-nitrodiphenylamine nor dibutyl sebacate is volatile or soluble enough for the partitioning to air or water to be important fate processes. 2-Nitrodiphenylamine has been found in river sediment receiving waste water runoff from an army ammunition plant; this is considered the most likely fate for this chemical. The information on dibutyl sebacate is too limited to determine its transport and partitioning in the environment. However, it is known to be rapidly biodegraded by a wide range of microorganisms. Both propylene glycol dinitrate and 2-nitrodiphenylamine are photolyzed and photooxidized in water. It is likely that these substances are similarly broken down in the air. The data on biodegradation of propylene glycol dinitrate and 2-nitrodiphenylamine are mixed. Some experiments indicate these compounds are readily degraded and others indicate limited biodegradation. A bioconcentration factor has been calculated only for 2-nitrodiphenylamine. It indicates that this chemical does not bioconcentrate in aquatic organisms or biomagnify in the food chain. People working in occupations in which Otto Fuel II is manufactured or used, such as personnel involved in clean up operations or waste treatment facilities handling Otto Fuel II, are most likely to be exposed to the chemical and its components. Incomplete data on disposal practices and levels in the environment prevented a determination of the likelihood of exposure of people !iving or working near hazardous waste sites. General population exposure to Otto Fuel II is not expected to occur because of the limited manufacture and use of the compound, and the suggested low mobility of Otto Fuel II and its components in the environment. However, the …