For this example, and as shown in  Table B-5  ( Conversion Factors ), the THC to TOG conversion  factor is 1.16. Therefore, the amount of TOG emitted by the A320 aircraft is an estimated 322  kilograms (or 278 kilograms times 1.16).  To speciate the TOG emissions, the  HAP speciation profile (i.e., the percentage of emissions associated with a particular HAP) is obtained. To then derive the emission rates for an  individual HAP, the mass fraction profile  is multiplied by the total amount of TOG  emission.  The calculation for obtaining the estimated emission rate for an individual HAP (i.e., benzene,  formaldehyde) is provided in  Equation B-4  ( Aircraft HAP Emissions Using TOG ).  APPENDIX B$_{ }$ For demonstration purposes,  Table B-6  ( Example HAP Emission Estimates ) provides the  emission estimate for the A320  aircraft example for three individual  HAPs. As shown, computed emission totals for ethylene, formaldehyde, and toluene emissions are approximately  43, 34, and 2 kilograms, respectively.  Source:  Recommended Best Practice for Quantifying Speciated Organic Gas Emissions from Aircraft Equipped with  Turbofan, Turbojet, and Turboprop Engines , May 27, 2009,  http://www.epa.gov/otaq/regs/nonroad/aviation/420r09901.pdf.  For large commercial and cargo aircraft, APUs generate on-board electricity and air conditioning  (A/C) while an airplane is taxiing or parked at the gate. In some cases, GPUs are used. APUs and  GPUs are traditionally powered with jet fuel and diesel fuel, respectively. At many airports, gate furnished electricity and air conditioning are used to supplement and/or replace  usage of APUs/GPUs.  With one exception, the procedure for calculating HAP emissions for an APU is the same as the  procedure used to compute HAP emissions for an aircraft eng ine, described in the previous  section. For APUs however, the amount of fuel consumed is based on the run time of an APU  B.2.2  Auxiliary Power Units  B.2.2.1 Methodology  Table B-6. Example HAP Emission Estimates  Aircraft Type  Engine  Type/Number  TOG  (kg)  HAP  Speciation  Profile (mass  fraction)  HAP  Emissions  (kg)  A320-100  CFM-56 / 2  278  Ethylene  0.15459  43.0  Formaldehyde  0.12308  34.2  Toluene  0.00642  1.78  Equation B-4. Aircraft HAP Emissions Using TOG  HAP$_{i }$Emissions (kg)  = TOG Emissions (kg) x Speciation Profile$_{i }$(mass fraction)  Where:  i = HAP of interest  56$_{ }$