A national chemical distribution company has been hit with five federal lawsuits since last year by current and former employees, alleging wage-and-hour theft and racial discrimination against its black workers.

The latest lawsuit against Univar USA, filed this week in a federal court in Houston, claims that two drivers, Elton Wilson and Michael Roberts, were regularly passed up for promotions,  compared to their white and Hispanic co-workers, and were treated aggressively by white supervisors throughout their tenure.