to the level given in “Evaluation of Factors that Affect Diesel Exhaust Toxicity”, ARB Contract No. 94-312, July 1998. In this report, diesel exhaust was measured from a Cummins L-10 engine using three diesel fuels including California low-aromatic diesel fuel. The results are shown in Table 4-32. These emissions were used to develop the emission factors in Table 4-31. Particulate emissions for this engine were 183 mg/bhp‑hr.
Table 4-32. Diesel Exhaust emissions in mg/bhp-hr
Diesel Fuel and Vapor
Diesel fuel was analyzed and speciated in a report done by California Institute of Technology and Oregon State University entitled “Characterization and Control of Organic Compounds Emitted from Air Pollution Sources”, Final Report, ARB Contract number 93-329, April 1998. In this report, diesel fuel was shown to have no toxic air contaminants. PAHs were measured but n-PAHs were not. Data for PAHs in diesel fuel are shown in Table 4-30. Since no data can be found on diesel fuel vapor, it is assumed that the same levels of PAHs and other TACs are the same as in the fuel itself.
LPG and Natural Gas
Natural gas and by-product LPG contain standard hydrocarbons which is consistent with the long-term geological origin of the fuel. Refinery-based LPG contains oeliphns such as propane LPG analyses are generally not performed to the same detail as gasoline speciations. However, since both LPG and natural gas are lower hydrocarbon gases, no toxic air contaminants or precursors should be present.
The petroleum refining industry converts crude oil into more than 2500 refined products, including LPG, gasoline, kerosene, aviation fuel, diesel fuel, fuel oils, lubricating oils and feedstocks for the petroleum industry. AP-42 gives emission factors for hydrocarbons and aldehydes for the various processes of petroleum refining. It is assumed that all petroleum refineries in the South Coast have emission control devices in place, thus the controlled emission factors were used. These are given in Table 4-33 for the various refinery processes. Over 99 percent of the hydrocarbons coming from a refinery are non-methane. While only total aldehyde emissions are given, it is assumed