(d) to the enforcement of any provision of law which is subject to enforcement by criminal penalties and which relates to the performance by persons employed by the department of taxation and finance of the duties of their employment.
Provided, however, that nothing in this subdivision shall be deemed to authorize any such employee designated as a peace officer after November first, nineteen hundred eighty-five to carry, possess, repair or dispose of a firearm unless the appropriate license therefor has been issued pursuant to section 400.00 of the penal law, and further provided that, prior to such designation by the commissioner each such employee shall have successfully completed the training requirements specified in section 2.30 of this article. Provided, further, that any license issued to such employee pursuant to such peace officer designation by the commissioner shall relate only to the firearm issued to such employee by the department of taxation and finance and such permit shall not cover any other firearms. The foregoing sentence shall not be deemed to prohibit such peace officer from applying for a separate permit relating to non-departmental firearms.