The following persons are exempt from this chapter while in the proper discharge of their professional duties:
(1) Persons authorized by the law of this state to practice medicine and surgery;
(2) Commissioned medical or surgical officers of the United States army, navy, air force or marine hospital service;
(3) Registered nurses;
(4) Duly registered cosmetologists operating in accordance with chapter 4 of this title; and
(5) Any person whose occupation or practice is confined solely to shampooing, as defined in § 62-4-102.