Some states are attempting to use the Industrial Source Complex (ISC) Dispersion Model to regulate cotton gins. There are a number of problems with the model and the regulatory process. The ISC Screen Model is very conservative. This leads to the possibility of overestimating emissions from a large percentage of cotton gins that are modeled using ISC Screen. This point is demonstrated by reviewing several trial runs made with the dispersion model. Another issue related to the attempted method of regulation is the property line concentration regulatory agencies would like to use. Recommendations are made to address the property line concentration limit controversy.