225 ILCS 37/30
The Department may issue a license as a licensed environmental health practitioner, without the required examination, to an applicant licensed under the laws of another state if the requirements for licensure in that state are, on the date of granting the license, substantially equal to the requirements of this Act. The Department shall issue a license as a licensed environmental health practitioner to any applicant who holds a Registered Environmental Health Specialist/Registered Sanitarian credential in good standing with the National Environmental Health Association. An applicant under this Section shall pay all required fees. Applicants have 3 years from the date of application to complete the application process. If the process has not been completed within 3 years, the application shall be denied, the fee forfeited, and the applicant must reapply and meet the requirements in effect at the time of reapplication.
225 ILCS 37/30