No female under eighteen (18) years of age shall be employed or permitted to work in, or in connection with, any establishment before the hour of six o'clock in the morning or after the hour of nine o'clock in the evening of any day, except that students sixteen (16) years of age and over whose employment is part of a recognized school work program, supervised by a recognized school authority may be employed until ten o'clock P.M.
43 P.S. § 105