WORKING PERMITS: Every minor 14 through 17 years of age must have a working permit unless otherwise stated in Chapter 4109. Minors must be at least 14 years of age to obtain a work permit.Age certificates are not issued, but proof of age is required for minors 16 and 17 years of age for employment during school vacation. Generally, youth who are 16 and 17 years old may work in a broad range of jobs, but cannot work in jobs that Ohio has deemed are too hazardous. If you are 18 years old, you may work at any time in any job. Work Permit: Mandatory for minors under 16 at any time as well as for 16 and 17 year olds during the school year. Minors aged 16 and 17 have slightly different regulations. They can work before 7 a.m. There are both state and federal laws that protect workers under the age of 18 from being exposed to hazards and working unreasonable shifts.