Any person sixteen years of age or over may be employed by an employer holding a permit issued under this chapter, except that (1) any person fifteen years of age or older may be so employed by such an employer on premises operating under a grocery store beer permit, and (2) any person under the age of eighteen who is employed on any permit premises shall not serve or sell alcoholic liquor. An employee eighteen years of age or over who is located on the grocery store beer permit premises shall approve all sales of beer on such premises. A minor performing paid or volunteer services of an emergency nature shall be deemed to be an employee subject to the provisions of this section.