You can find more information concerning split specimens in several sections of this part:
§40.3—Definition.
§40.65—Quantity of split specimen.
§40.67—Directly observed test when split specimen is unavailable.
§§40.71–40.73—Collection process for split specimens.
§40.83—Laboratory accessioning of split specimens.
§40.99—Laboratory retention of split specimens.
§40.103—Blind split specimens.
§40.153—MRO notice to employees on tests of split specimen.
§§40.193 and 40.201—MRO actions on insufficient or unavailable split specimens.
Appendix D to Part 40—Report format for split specimen failure to reconfirm.