Texas Transportation Code - TRANSP § 546.021. Mutual Aid Organizations

(a) Two or more businesses whose activities require the maintenance of fire-fighting equipment may form a mutual aid organization in which the member businesses agree to assist each other during an emergency by supplying fire-fighting equipment or services.

(b) The presiding officer or director of an organization formed under this section shall deliver a list to the county fire marshal, or to the commissioners court of a county if the county does not have a fire marshal, in each county in which a member business is located.  The list must contain the name of the registered owner and license plate number of each motor vehicle that each member intends to use in supplying fire-fighting equipment or services.

(c) If the county fire marshal or commissioners court determines that the operation of the vehicles on the list is in the public interest and not a threat to public safety, the marshal or court shall approve the list.

(d) On approval of the list by the county fire marshal or commissioners court, a person operating a listed motor vehicle in response to a call for emergency fire-fighting assistance from a member has the rights and restrictions placed by this subtitle on the operator of an authorized emergency vehicle.

(e) A county is not liable for damage to a person or property caused by a person approved by the county under this section to operate a motor vehicle for emergency fire-fighting assistance.