5. Jp-8 Exposure Scenarios

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5. JP-8 Exposure Scenarios

Exposure to JP-8 occurs to military and civilian avionics, aircraft maintenance, and fuel handling personnel through dermal contact with raw fuel or with clothing/gloves saturated with fuel. Through respiratory exposure to fuel in vapor or aerosol phase, or occasionally through oral exposure to atmospheric aerosol or to fuel-contaminated food or water (Harris et al., 1997, Pleil et al., 2000). Exposure of military personnel to JP-8 can also occur through more atypical uses of the fuel. These uses include fueling of land vehicles and equipment, fueling of heaters, use of JP-8 as a coolant (heat sink) in aircraft, aerosolization of JP-8 for use as a combat obscurant, use of JP-8 to suppress environmental sand or dust, or use of JP-8 as a carrier for herbicide applications (Ritchie et al., 2001a). Exposure of non-military, non-avionics personnel to JP-8 occurs primarily through atmospheric, soil or groundwater contamination with JP-8 or its combustion products, or through off-gassing from the skin and clothing of fuel-exposed personnel (Ritchie et al., 2001a). Major identified sources of atmospheric and groundwater contamination with JP-8 include: 1) unavoidable leakage or accidental spillage of JP-8 from manufacturing facilities, transportation and storage systems (including pipelines); 2) fueling/defueling/maintenance operations, aircraft and vehicle operation (including cold start-up of engines); and 3) occasional atmospheric jettisoning (usually above 6,000 ft.) of JP-8 during emergency aircraft landing (Pfeiffer, 1994).

Carlton and Smith (2000) measured JP-8 and benzene exposures during aircraft fuel tank (foam-filled) entry and repair at twelve USAF bases. Breathing zone samples were collected on the fuel handlers during occupational assignments, while instantaneous samples were taken at various points during the procedures with SUMMA canisters and subsequent analysis by mass spectrometry. The highest 8-hr time-weighted average (TWA) was 1304 mg/m3; the highest short-term (15-min average) exposure was 10,295 mg/m3. The instantaneous sampling results indicated benzene exposures during fuel tank repair up to 49.1 mg/m3. These readings occurred within aircraft fuel tanks, from which foam blocks soaked with JP-8 were inspected and removed. In this worst case scenario, workers entering the tanks are required to wear self-contained breathing apparatus (SCBA) and chemically-resistant gloves and boots, but only cotton jumpsuits, allowing extensive dermal exposure. Personnel working outside the fuel tanks, but assisting in removal of the foam blocks, do not typically wear SCBAs, allowing both extensive dermal and respiratory exposure to JP-8 (Pleil et al., 2000).

JP8HazardsStudy.doc