International Civil Aviation Organization (ICAO) member nations and airline safety advocates will attempt this month to legislate a safer way to transport billions of lithium-chemistry batteries by air every year. Recommendations being considered by the 20-member Dangerous Goods Panel could drastically change how the batteries are packed and shipped. 

Proposals include: an outright ban on shipping lithium-ion batteries in passenger aircraft until better packaging is available, requiring airlines to complete mandatory risk assessments before transporting them, shipping at lower levels of charge than currently done and removing the so-called lithium battery “loophole” that allows for unlimited numbers of small batteries to be shipped in bulk without the typical hazardous material notifications to the airline. 

The panel meets three times every two years, with October’s final meeting the capstone where final agreements on new or revised technical instructions for shipping will notionally be approved and set for implementation Jan. 1, 2017.

The need for change has been highlighted by at least two cargo aircraft losses where bulk shipments of individual lithium batteries or cells were implicated—a UPS DC-8 freighter in Philadelphia in 2006 and a fatal UPS Boeing 747-400 freighter crash at Dubai in September 2010—and by a growing portfolio of battery testing results by the FAA at its Atlantic City International Airport Technical Center in New Jersey. Researchers there have shown that fires in bulk shipments of lithium-metal batteries—the nonrechargeable batteries used in cameras, watches and other consumer electronics—cannot be extinguished by the Halon fire suppressant used in aircraft cargo holds, and that the same suppressant is only “marginally effective” in putting out lithium-ion battery fires. The situation is worse for freighter aircraft with “Class E” main deck cargo areas that generally have no active fire suppressant.

The failure mechanism for both chemistries typically starts with the “thermal runaway” of a single cell, which can be caused by damage, heat, overcharging, undercharging or other factors. Once a cell vents, spewing flammable electrolytes at temperatures above 1,100F, the adjacent cells then follow suit and the packaging, typically a cardboard box that ignites at 400-500F, becomes engulfed in flames.

The FAA used as many as 5,000 lithium-ion cells in bulk (and 4,800 lithium-metal cells) for testing, but actual cargo loads can contain 50,000 cells or more. Even when fire suppressant dampens flames, the FAA has shown that gases released by only a handful of batteries in thermal runaway can accumulate and cause a blast that can destroy a cargo container. The agency also demonstrated that a 30% state of charge (compared to the 50% at which batteries are normally shipped) will limit thermal runaway between cells, a finding fueling proposals to limit the charge levels of the batteries before shipment.

Pilots flying the cargo may not be aware of the actual threat level, thanks to the unintended consequences of an ICAO 2012 rule change relaxing controls for small shipments of the same types of small lithium batteries the FAA tested. Section II of the technical instructions for shipping dangerous goods allows shippers to package two batteries (100 Wh maximum energy for lithium-ion batteries) or eight individual cells (20 Wh maximum each for lithium-ion cell) in approved packaging that meets drop test and other requirements—but without the more rigorous documentation, employee training and other requirements needed to transport dangerous goods. Section II is often referred to as the “lithium loophole.”

“Unfortunately, what’s happening is that shippers are overpacking the Section II shipments,” says first officer Mark Rogers, Dangerous Goods Committee chairman for the International Federation of Air Line Pilots Associations (Ifalpa). “They’ll take a small cardboard box with eight cells, then put many of those boxes together in a larger box [an overpack] and put those boxes together in a high-density pallet.”

Michael Moody, Jr., a UPS captain and chairman of the Independent Pilots Association (IPA) safety committee, says there could be “hundreds, and even thousands of batteries” within the larger overpack box. IPA is the union representing UPS pilots. “Section II packages do not require any notification or declaration. In other words, the pilot has no idea that they are on board the aircraft,” says Moody, adding that even airlines that state they are voluntarily refusing to transport lithium batteries may not be aware they are carrying Section II cargo unless they visually search every package, since there is no paperwork to consult.

Ifalpa has four main proposals for the Dangerous Goods Panel, of which it is a member. Some overlap with the 14 recommendations for a multilayered safety net crafted by ICAO’s government and industry Multidisciplinary Working Group over the past two years. Among them is a call for improved cargo safety standards for freighters (possibly including fire-resistant containers and pallet covers or a reduction in the number of cells or batteries allowed to be carried on the aircraft or in specific compartment) a request to eliminate Section II and a proposal to create a performance-based packaging standard that will define the criteria and processes a shipper can use to demonstrate that packaging is able to contain a thermal runaway. Detailed performance standards could include a requirement that no flames or fragments exit the package or that certain temperature limits are not exceeded. However, Rogers says such a standard is several years from reality, making it essential that lithium-ion batteries be prohibited  from passenger aircraft in the interim.

“The ultimate solution is packaging that will ensure that a shipper determines the safe number of batteries in the package in order to meet the standard that no hazardous effects of a fire can be seen outside the package,” he says. “Until that standard is in place, we have no real ability to determine a safe number of batteries, and we do not have the ability in the current regulatory scheme to limit the number of packages in the cargo compartment or on the aircraft.”

UPS, which has been hit harder than most in the industry, is being proactive. Working with the IPA, the carrier has deployed fire-resistant package containers for lithium batteries, fire-containment covers for cargo pallets (in Class E areas) and new safety equipment in the cockpit, including Emergency Vision Assurance Systems (EVAS) for cockpits. An EVAS is an airbag that inflates when the cockpit fills with smoke, allowing pilots to see through the windscreen. UPS continues to research enhanced fire-resistant containers, most recently developing a system that can reduce the potential for explosion when melting lithium batteries produce combustible gases. FedEx’s approach has been to deploy an aircraft-mounted fire suppression system for Class E cargo areas on all its widebody freighters.

Intervention is also taking place at the packaging level. Underwriters Laboratories, which became the NTSB’s go-to organization in 2013 for researching the failure mechanisms in the eight-cell main and backup lithium-ion batteries in the Boeing 787, says spacing of at least 2 mm (0.08 in.) between cells in a battery minimizes the chance for thermal runaway. But it says, “the proper method of minimizing the chance of thermal runaway propagation varies significantly with cell type and module configuration.” Boeing solved its 787 battery issues by providing more isolation between cells and making changes to the battery case, including a dedicated vent line to the outside of the aircraft.

AkroFire, a Kansas company that provides cargo container repair kits and shipping boxes for oxygen generators, has developed a “loose fill” packaging solution using “packing nuts” designed to fuse together and form a rigid protective barrier around batteries or cells when exposed to internally or externally generated heat or fire. President Jon Green says the Pyro Pax concept, which requires about 2 in. of spacing around the batteries or cells to be filled with the packing nuts, is aimed at smaller shipments of damaged or defective batteries but might also be a solution for an overpack shipment. During testing with as many as 300 CR123 lithium-metal cells triggered into a thermal runaway, Green says external temperatures on the cardboard box remained at approximately 200F, well below the ignition point for cardboard, while internal temperatures soared to nearly 2,000F as thermal runaway spread to all of the cells.