U.S. EPA regulation in 1987 mandated by the Asbestos Hazard Emergency Response Act (AHERA) of 1986 required that all public and private elementary and secondary schools in the U.S. be inspected for the presence of asbestos in building materials. The regulations also required that the commercial asbestos laboratories which would analyze the bulk samples taken from these school buildings be routinely monitored to determine the quality and integrity of the analytical work being performed and earn accreditation to perform such analyses. The National Bureau of Standards, now the National Institute of Standards and Technology (NIST), was charged with developing such a laboratory accreditation program and initiated a program known as the National Voluntary Laboratory Accreditation Program (NVLAP) for bulk asbestos laboratories which analyze building materials for asbestos by polarized light microscopy (PLM).
