Texas Transportation Code - TRANSP § 547.202. Department Certification or Approval of Vehicle Equipment

(a) When or after an item of vehicle equipment is sold in this state, the department shall determine whether a department standard is prescribed for the item. If a department standard is prescribed, the department shall determine whether the item complies with the standard.

(b) If a standard of an agency of the United States or of the department is not prescribed, the department by rule may require departmental approval before the sale of the item.