Note: Proficiency testing policies and other documentation included on this website reflect the operations of AIHA Proficiency Analytical Testing Programs, LLC but may refer to the American Industrial Hygiene Association or AIHA since AIHA PAT Programs, LLC programs were once operated by AIHA. Some of these documents may also include the AIHA logos. Please note that these reference documents have been contributed by AIHA for use by AIHA PAT Programs, LLC until the LLC adopts updated versions of the documents.