49 CFR 40.201 : Transportation (§ 1.1 To Parts 1581-1699) — (§ 1.1 To Appendix To Subtitle A) — Office Of The Secretary Of Transportation (§ 1.1 To Appendix To Subtitle A) — Procedures For Transportation Workplace Drug And Alcohol Testing Programs (§ 40.1 To Appendix H To Part 40) — Problems In Drug Tests (§ 40.191 To § 40.209) — What problems always cause a drug test to be cancelled and may result in a requirement for another collection?