The U.S. Federal Aviation Administration (FAA) warned airlines that lithium ion batteries pose a potential danger to airplanes if being carried as freight. The statement was made on Tuesday, highlighting the potential "risk of a catastrophic hull loss", and urging airlines to reconsider the risks after allowing lithium ion batteries to be transported in the cargo and to reevaluate their cargo protocols regarding that matter.

The warning was stated after a series of tests which concluded that lithium-ion batteries carried as cargo can lead to a catastrophic explosion. The FAA also explained that aircraft' fires suppression systems are incapable of preventing the explosion that could be caused by lithium-ion battery fires.

Fortune described the risks of carrying lithium-ion batteries in airplane cargos. It's noted that if one portion of the battery overheats, the batteries' chemical properties will begin to generate additional heat that would, in turn, spread the reaction, frequently ending in an explosion. Lithium-ion batteries could overheat due to short circuit, physical damage, or simply external temperatures above 60 degrees Celsius or 140 degrees Fahrenheit.

The risk is evident especially when multiple batteries are tightly packed with limited ventilation. That would likely be the case when batteries are transported or used in a device. The FAA determined that it could only take eight batteries to leak the plane's cargo hold, causing an intense fire in the aircraft.

ABC News reported that lithium-ion batteries had caused fires on Boeing 747s in Dubai and South Korea in 2010 and 2011. No passengers were on board at that time, but the incident had killed all crew members. In 2013, the FAA ground the Boeing 787s Dreamline fleet because of a series of battery fires in the batteries of the aircraft. Last year, lithium-ion batteries from a flight attendant's credit card reader forced a flight to do an emergency landing in Buffalo.

The incidents have urged transportation authorities to reevaluate regulations and protocols regarding lithium ion batteries on airplane cargos. According to Bloomberg, The National Transportation Safety Board pressured airlines to require battery shipments to be separated from other flammable materials on cargo planes, as well as limiting the number of lithium-ion to be transported in one aircraft.

Other authority figures are pushing forward to make regulations that would ban the lithium ion batteries from being transported in airplane cargoes. Over the last 25 years, the FAA has recorded up to 140 incidents involving the batteries. For now, the FAA could only warn airlines to re-evaluate the procedures and internal regulations regarding lithium ion batteries.