Upon a determination by the Administrator, a laboratory will be placed on probation for the following reasons:

1. (a) If the laboratory fails to complete more than one interlaboratory accreditation maintenance check sample analysis as required by § 439.20(d) of this part within 12 consecutive months, unless written permission is granted by the Administrator.
2. (b) If the laboratory fails to meet any of the criteria set forth in §§ 439.20(d) and 439.20(h) of this part.