|(a) In specific cases the executive director may approve a variance from the requirements of this chapter if the variance is not contrary to the public health and safety and, due to special conditions, a literal enforcement of this chapter would result in unnecessary hardship, and so that the spirit of the chapter is observed. A variance may not be approved concerning the procedural requirements of this chapter, including application procedures and the filing of reports, or concerning the provisions of §332.8 of this title (relating to Air Quality Requirements). (b) A request for a variance must be submitted in writing to the executive director. The request may be made in an application for a registration or permit. Any approval of a variance must be in writing from the executive director. (c) If the variance is requested for a facility permitted under this chapter, the commission must approve the variance.