A drum of nitric acid exploded inside a truck Thursday on Interstate 83 in northern Baltimore County, splashing over vehicles and shutting down traffic in both directions for hours.
Maryland environment officials said a chemical reaction between the acid and its steel container caused the explosion, and the warm weather may have caused the drum to overpressurize.
“We?ve got to look into this and find out why this particular material was in a steel drum, because it should not have been,” said Richard McIntire, a spokesman for the Maryland Department of the Environment.
McIntire said 20 other drums on the truck carried a nitrogen and methane-based waste product and were not affected. The explosion created a rust-colored cloud and chemicals splashed onto several vehicles.
The six-wheeled truck is owned by North Carolina-based EcoFlow and was licensed to carry hazardous materials. McIntire said the materials were being transported out of the state from Charles County for proper disposal.
State highway officials said the major commuter thoroughfare known as the Harrisburg Expressway was closed in Parkton between York Road and Route 439 for an hour and a half. Northbound motorists were detoured onto York Road at Exit 33 and southbound drivers were forced off the road at Exit 36.
The southbound lanes were reopened at 3:30 p.m., according to State Highway Administration spokesman David Buck, but traffic backed up for at least four miles. Northbound lanes remained closed through rush hour into late evening.
Buck said SHA adjusted the timing of traffic signals on York Road to accommodate the volume. “There?s still a lot of trucks and hills in these parts, though, which makes it even slower,” he said.
McIntire said the drums were repacked into larger drums and continued on their way to disposal. He said the department will investigate why nitric acid was being transported in a steel drum.
