Tenn. Code Ann. § 68-102-303

No municipality, county, or political subdivision shall operate a fire department, and no organization, agency, or entity shall operate as a fire department within the state of Tennessee, unless it has been duly recognized to do so pursuant to this part by the department of commerce and insurance, state fire marshal's office. The state fire marshal, in consultation with the Tennessee Fire Chiefs Association (TFCA), shall promulgate rules and regulations pursuant to the Uniform Administrative Procedures Act, compiled in title 4, chapter 5, relative to the standards and qualifications for becoming and remaining a fire department.