(a) An ELAP certified laboratory shall successfully analyze proficiency testing samples for those fields of testing for which they are certified, not less than once a year, where applicable. Proficiency testing procedures shall be approved by the United States government or by the state board.
(b) A TNI accredited laboratory shall participate in, and meet the success rate for, proficiency testing studies as required in the TNI standards.
(c) The ELAP certified or TNI accredited laboratory shall discontinue the analyses of samples for the fields of testing or subgroups which have been suspended for failure to comply with the proficiency testing requirements in this section.