Samples shall be analyzed and the results returned to the PT study provider no later than 45 calendar days from the scheduled study shipment date. The laboratory shall ensure that all PT samples are handled, i.e., managed, analyzed and reported, in the same manner as actualenvironmental samples utilizing the same staff, methods as used for routine analysis of that analyte, procedures, equipment, facilities, and frequency of analysis.
Okla. Admin. Code § 252:301-7-3