N.J. Stat. § 26:1A-41
The commissioner shall, in the name of the department, issue the following licenses:
However, any health officer's license, sanitary inspector's license, and plumbing inspector's license issued before the effective date of P.L. 1947, c.177 (C.26:1A-1 et seq.) by the Department of Health shall, unless suspended or revoked in accordance with the provisions of sections 43 and 44 of that act, remain in effect during the employment as such of the holder thereof. Upon enactment of P.L. 1997, c. 416(C.26:1A-42.1 et al.) any existing Sanitary Inspector, First Grade license shall become a Registered Environmental Health Specialist license without any further action required of the licensee.
Any license eliminated by P.L. 1997, c. 416(C.26:1A-42.1 et al.) shall, unless suspended or revoked in accordance with the provisions of sections 43 and 44 of P.L. 1947, c.177 (C.26:1A-43 and C.26:1A-44), remain in effect until the holder thereof does not renew the license within two years from the date of its expiration, or the commissioner does not renew the license in accordance with section 42 of that act, whichever comes first.
N.J.S. § 26:1A-41