Washington Revised Code Title 70. Public Health and Safety § 70.42.070. Proficiency testing program

(1) Except where there is no reasonable proficiency test, each licensed test site must participate in a department-approved proficiency testing program appropriate to the test or tests which it performs. The department may approve proficiency testing programs offered by private or public organizations when the program meets the standards set by the department. Testing shall be conducted quarterly except as otherwise provided for in rule.

(2) The department shall establish proficiency testing standards by rule which include a measure of acceptable performance for tests, and a system for grading proficiency testing performance for tests. The standards may include an evaluation of the personnel performing tests.