N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 56-4.6
The same NIOSH approved methodology for project air sampling and for analysis of the air samples shall be used at all phases of an asbestos project that require area air sampling and analysis, with the possible exception of clearance air sampling. Phase contrast microscopy (PCM) shall be the minimum acceptable method of analysis. In lieu of PCM clearance air sampling and analysis, the building/structure owner may elect to utilize TEM air sampling and analysis to meet clearance air sampling requirements. If transmission electron microscopy (TEM) is the selected method of analysis, the clearance criteria and sampling protocols of the Asbestos Hazard Emergency Response Act (AHERA) shall be used. If PCM air sample analysis results exceed the satisfactory clearance air criteria under this Part, then TEM analysis of the entire set of clearance air samples may be used, provided that a standard NIOSH/ELAP accepted laboratory analysis method is used that shall report each air sample result in fibers per cubic centimeter, for appropriate correlation to the original unsatisfactory PCM clearance air sample results and the established background levels, and provided that a report is submitted to the commissioner for the entire set of clearance air sample PCM and TEM laboratory analyses.
N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 56-4.6