Texas Health and Safety Code - HEALTH & SAFETY § 401.063. General Inspection Authority

(a) The department or commission or the agency's representative may enter public or private property at reasonable times to determine whether, in a matter under the agency's jurisdiction, there is compliance with this chapter and the agency's rules, licenses, registrations, and orders under this chapter.

(b) The department or commission or the agency's representative may enter an area under the jurisdiction of the federal government only with the concurrence of the federal government or its designated representative.