(WASHINGTON) — The National Transportation Safety Bureau (NTSB) has issued a warning highlighting the fire risk inherent in scrap metal cargoes, particularly from hazardous and flammable contaminants like lithium-ion batteries.
While scrap metal is not rated as a hazardous cargo, and is usually treated like any other bulk commodity, the NTSB has cautioned that such cargoes “have the potential of creating risks while being shipped.
The warning was prompted by the results of an investigation of a fire last year aboard Daisy Mae, a scrap barge in the Delaware Bay that was hot enough to melt the barge’s cargo of scrap metal.
The barge was loaded with about 7,000 tons of low-grade steel scrap, known in the trade as “shredder feed,” loaded in Newark, N.J., bound for an industrial shredding facility in Camden, N.J. Shredder feed is a mixture of recyclable waste steel such as crushed cars, appliances, and any other steel scrap bigger than a quarter of an inch in thickness. The grade of scrap also usually contains amounts of non-steel waste.
While headed up Delaware Bay toward Camden, a fire was detected aboard the barge. Six firefighting boats and a Coast Guard response boat responded to the scene and the fire, largely confined to the barge’s stern, was completely extinguished within 24 hours.
On inspecting the fire-damaged scrap, NTSB and the Coast Guard found that some of the metal had liquefied, then re-hardened into large chunks. In the undamaged scrap, the inspectors found plastic waste, rubber tires and electrical components, among other flammables.
Though the exact cause of the fire could not be determined, the NTSB identified many possible ignition sources, like sparks from shifting and grinding metal during transit, self-heating materials like oily rags, or improperly-disposed-of lithium-ion batteries.
“Metallic and nonmetallic hazardous materials often are present within shoreside scrap metal piles and could be loaded onto vessels. These often-flammable materials elevate the fire risk and can lead to intense fires,” noted NTSB.
“Qualified cargo-surveying personnel can assist the vessel’s captain before and during loading operations to limit the presence of hazardous, combustible material in scrap metal. Thermal imagery is an effective tool that could be used to identify hot spots in scrap metal cargo at shoreside facilities,” the agency advised.