Sounds like a nightmare situation for an owner-operator team based out of Nevada, according to LandLine Magazine. A driver's hazmat background check expired, which Nevada then took as a trigger to suspend his CDL. According to the article:
As it turns out, Rod’s hazmat endorsement background check expired in late September. Because he hadn’t hauled hazmat for some time, Rod decided not to renew his endorsement. He would renew his CDL the first week of October...
Under 383.51, a driver can be disqualified for “driving a commercial motor vehicle without the proper class of CDL and/or endorsements for the specific vehicle group being operated or for the passengers or type of cargo being transported.” Baillie, however, was not hauling hazmat.
This is yet another example of why fleets and owner-operators need to stay on top of hazmat driver training. This is not too different from the recent rule changes about who is a hazmat hauler and who is subject to their lower hazmat CSA thresholds.