I followed the suggestion of
red456 and contacted the State of New Jersey on the issue in question. The reponse I got was:
Thank you for your inquiry regarding backscatter x-ray screening and its potential use at New Jersey airports. These units if purchased and operated by Federal employees will be exempt from our regulatory oversight. Such devices will not be registered or inspected by our program.
I followed up and asked why the exemption but so far have not received a response. If I do, I will post it.