(a) The following exemptions apply in the Beaumont-Port Arthur, Bexar County, Dallas-Fort Worth, El Paso, and Houston-Galveston-Brazoria areas.(1) Any tank-truck tank which is used exclusively to transport volatile organic compounds (VOC) with a true vapor pressure less than 0.5 pounds per square inch absolute under actual storage conditions is exempt from the requirements of this division (relating to Control of Volatile Organic Compound Leaks From Transport Vessels).(2) Transport vessels other than tank-trucks are exempt from the requirements of this division.(3) Any tank-truck tank that is a portable tank, as defined in 49 Code of Federal Regulations 171.8, is exempt from the requirements of this division.(b) In the covered attainment counties, transport vessels other than tank-trucks are exempt from the requirements of this division.