The pollutant-to-pollutant conversion factors file is required when there is a mismatch between the pollutant in the inventory and the pollutant for which the speciation profiles have been developed. One example is when the inventory has VOC (or ROG), but the speciation profiles were developed for TOG. SMOKE permits such a factor to be applied to any pollutant. The same format is used by all source categories. The available combinations and hierarchies for applying the factors are the same as for the speciation cross-reference (see Section 6.15, “Spcmat”), with the exception of the plant ID and other more specific source characteristics for point sources. The GSCNV file is not needed if there is no mismatch between the inventory and the pollutants in the speciation profiles file. The Spcmat program will input this file wheh the POLLUTANT_CONVERSION environment variable is set to Y.

If emissions types (emission process/pollutant combinations) are being used, as with mobile source processing using the Emisfac program (see Section 2.8.4.5, “Emission processes”), the emission type must be listed instead of the pollutant. For example, if exhaust running VOC emissions were being converted to exhaust TOG, then EXR__VOC and EXR__TOG would need to appear in their respective columns on the header line (line 1 in the format below). It would not be correct to put only VOC and TOG. All emission types must be listed, or the conversion factor that will be applied is 1. This approach permits conversion factors that are specific to each emission process (e.g., different conversions for EXR and EXS).

The format of the GSCNV file is shown in Table 8.61, “Format for GSCNV”.