Tex. Nat. Res. Code § 113.054

The rules and standards promulgated and adopted by the commission under Section 113.051 preempt and supersede any ordinance, order, or rule adopted by a political subdivision of this state relating to any aspect or phase of the liquefied petroleum gas industry. A political subdivision may petition the commission's executive director for permission to promulgate more restrictive rules and standards only if the political subdivision can prove that the more restrictive rules and standards enhance public safety.