In compliance with a provision on the new highway act, the Pipeline and Hazardous Materials Safety Administration has withdrawn a notice of proposed rulemaking that would have amended haz-mat regulations on the transportation of “flammable liquid material in unprotected external product piping,” a.k.a. wetlines, on DOT-spec tanker trucks.

The withdrawal notice was published in the Federal Register for Dec. 30.

The proposal, which dates back to 2011, would have limited the amount of flammable liquid that could be carried in the unprotected loading/unloading wetlines of tankers.

PHMSA had contended there was a risk that fuel held in wetlines could spill and ignite in an accident.

However, tank carriers argued that the expense of installing pumps to empty the wetlines would far outweigh the benefits, especially given the added risk of explosion from welding retrofit pumps onto tank trailers.

According to Gordon Delcambre, Jr., PHMSA public affairs specialist, the notice’s withdrawal was mandated by Congress in the Fixing America's Surface Transportation (FAST) Act highway bill that was signed into law by President Obama earlier this month.

“Although PHMSA is withdrawing its rulemaking proposal, the agency will continue to consider methods to improve the safety of transporting flammable liquid by cargo tank motor vehicle,” stated the notice.

PHMSA added that it will “continue to analyze current incident data and improve the collection of future incident data to assist in making an informed decision on methods to address this issue further, if warranted.”