(a) a minor under 16 years old may not be permitted to work: (i) more than three hours in one school day;. (ii) more than 18 hours in one school week;.R610-2-4. Employment of Minors Engaged in Door-to-Door Sales, License. Utah child labor laws. Minors under the age of 16. However, employers of minors under age 18 must obtain and keep on file proof of the minor's age. Unlike some states, Utah does not require minors under 18 to obtain a work permit. No one under the age of 18 may be employed in a hazardous job, though (see below). Under the FLSA, when school is in session, 14- and 15-year-olds can work three hours on a school day or 18 hours in a school week. Minors 14 years of age or older may work in a variety of nonhazardous occupations, including: Retail food services.