Three oil companies are being hit by the Department of Transportation for improperly labeling crude oil headed for shipment on railways.
The Transportation Department is proposing fines totaling $93,0000 on the companies, which it argues did not properly label oil being transported from the Bakken region.
The notices of the possible violations were sent Tuesday to Hess Corporation, Whiting Oil and Gas Corporation and Marathon Oil Company.
"The fines we are proposing today should send a message to everyone involved in the shipment of crude oil: You must test and classify this material properly if you want to use our transportation system to ship it."
The proposed fines come amid growing concerns about oil traveling by rail. There have been a handful of explosions and spills related to oil being transported by train.
If oil is not properly classified, the department said, emergency responders will not be able to handle it accurately, and responders could possibly follow the wrong procedures when responding to a spill.
Out of 18 samples taken from cargo tanks during the investigation, 11 were not places in the right "packing group," the Transportation Department said in a statement.
"These initial findings remind us how important it is to follow the hazardous materials regulations and to do it in the proper sequence," said Pipeline and Hazardous Materials Safety Administrator Cynthia Quarterman.
Regulators bulked up oversight within the last year, launching "Operation Classification" to increase sampling and inspections. Tuesday's findings are the first test results announced from the investigation.