AbstractAs new programs are initiated by industry and federal or state regulatory agencies to reduce releases of hazardous air pollutants and reactive volatile organic compounds into the atmosphere, there are increasing questions over the loss of organic compounds from fugitive sources, the best method to estimate these losses, and the factors that influence these losses. The presently established method is to use generalized emission factors for each specific piece of equipment comprising a process unit. The accuracy of the estimates obtained using the available emission factors depends upon two features. These are first, the precision and accuracy of the actual emission factors or correlations themselves, and second, the resemblance of the systems from which the correlations were developed to those for which they will be applied.