Hazardous Materials: Enhanced Safety Provisions for Lithium Batteries Transported by Aircraft (FAA R
Updated: Jun 14, 2019
Hazardous Materials: Enhanced Safety Provisions for Lithium Batteries Transported by Aircraft (FAA Reauthorization Act of 2018)
Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT.
Interim final rule (IFR).
PHMSA issues this interim final rule (IFR) to revise the Hazardous Materials Regulations for lithium cells and batteries transported by aircraft. This IFR prohibits the transport of lithium ion cells and batteries as cargo on passenger aircraft; requires lithium ion cells and batteries to be shipped at not more than a 30 percent state of charge aboard cargo-only aircraft when not packed with or contained in equipment; and limits the use of alternative provisions for small lithium cell or battery shipments to one package per consignment. This IFR does not restrict passengers or crew members from bringing personal items or electronic devices containing lithium cells or batteries aboard aircraft, or restrict cargo-only aircraft from transporting lithium ion cells or batteries at a state of charge exceeding 30 percent when packed with or contained in equipment or devices.
Effective date: This interim final rule is effective on March 6, 2019.
Comment date: Comments must be received by May 6, 2019.
You may submit comments identified by Docket Number [PHMSA-2016-0014 (HM-224I)] by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the online instructions for submitting comments.
Mail: Docket Operations, U.S. Department of Transportation, West Building, Ground Floor, Room W12-140, Routing Symbol M-30, 1200 New Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: To Docket Operations, Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal Holidays.
Instructions: All submissions must include the agency name and docket number for this rulemaking at the beginning of the comment. Note that all comments received will be posted without change to the docket management system, including any personal information provided.
Docket: For access to the dockets to read background documents or comments received, go to http://www.regulations.gov or DOT's Docket Operations Office (see ADDRESSES).
Privacy Act: In accordance with 5 U.S.C. 553(c), DOT solicits comments from the public to better inform its rulemaking process. DOT posts these comments, without edit, including any personal information the commenter provides, to www.regulations.gov, as described in the system of records notice (DOT/ALL-14 FDMS), which can be reviewed at www.dot.gov/privacy.
FOR FURTHER INFORMATION CONTACT:
Shelby Geller, (202) 366-8553, Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration, U.S. Department of Transportation, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.
Table of Contents
I. Executive Summary
II. Current Lithium Battery Transportation Requirements
III. Need for the Rule
A. FAA Technical Center Testing
B. ICAO Activities
C. Risk Potential
D. Alternative Transport Conditions
IV. Good Cause for Immediate Adoption
V. Summary of Changes
A. Passenger Aircraft Prohibition
B. State of Charge Requirement
C. Consignment and Overpack Restriction
D. Limited Exceptions to Restrictions on Air Transportation of Medical Device Cells or Batteries
VI. Regulatory Analysis and Notices
A. Statutory/Legal Authority for This Rulemaking
B. Executive Order 12866 and DOT Regulatory Policies and Procedures
C. Executive Order 13771
D. Executive Order 13132
E. Executive Order 13175
F. Regulatory Flexibility Act, Executive Order 13272, and DOT Regulatory Policies and Procedures
G. Paperwork Reduction Act
H. Regulation Identifier Number (RIN)
I. Unfunded Mandates Reform Act
J. Environmental Assessment
K. Privacy Act
L. Executive Order 13609 and International Trade Analysis
List of Subjects
I. Executive Summary
The safe transport of lithium batteries by air has been an ongoing concern due to the unique challenges they pose to safety in the air transportation environment. Unlike other hazardous materials, lithium batteries contain both a chemical and an electrical hazard. This combination of hazards, when involved in a fire encompassing significant quantities of lithium batteries, may exceed the fire suppression capability of the aircraft and lead to a catastrophic loss of the aircraft.
The Pipeline and Hazardous Materials Safety Administration (PHMSA) issues this interim final rule (IFR) to amend the Hazardous Materials Regulations (HMR; 49 CFR parts 171-180) to (1) prohibit the transport of lithium ion cells and batteries as cargo on passenger aircraft; (2) require all lithium ion cells and batteries to be shipped at not more than a 30 percent state of charge on cargo-only aircraft; and (3) limit the use of alternative provisions for small lithium cell or battery to one package per consignment. These amendments will predominately affect air carriers (both passenger and cargo-only) and shippers offering lithium ion cells and batteries for transport as cargo by aircraft. The amendments will not restrict passengers or crew members from bringing personal items or electronic devices containing lithium cells or batteries aboard aircraft, or restrict the air transport of lithium ion cells or batteries when packed with or Start Printed Page 8007contained in equipment. To accommodate persons in areas potentially not serviced daily by cargo aircraft, PHMSA, through the requirement in the FAA Reauthorization Act of 2018, is providing a limited exception, with the approval of the Associate Administrator, for not more than two replacement lithium cells or batteries specifically used for medical devices to be transported by passenger aircraft. Furthermore, these batteries may be excepted from the state of charge requirements, when meeting certain provisions. See “Section V.D. Limited Exceptions to Restrictions on Air Transportation of Medical Device Cells or Batteries” for further discussion.
This IFR is necessary to address an immediate safety hazard, meet a statutory deadline, and harmonize the HMR with emergency amendments to the 2015-2016 edition of the International Civil Aviation Organization's Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO Technical Instructions). The serious public safety hazards associated with lithium battery transportation and the statutory deadline in the FAA Reauthorization Act of 2018 necessitate the immediate adoption of these standards in accordance with sections 553(b)(3)(B) and 553(d)(3) of the Administrative Procedure Act (APA). While PHMSA values public participation in the rulemaking process, the current risk of a lithium battery incident and statutory deadline imposed by Congress makes it impractical and contrary to public interest to delay the effect of this rulemaking until after a notice and comment period. However, with the publication of this IFR, PHMSA encourages persons to participate in this rulemaking by submitting comments containing relevant information, data, or views. PHMSA will consider all comments received on or before the IFR closing comment date, consider late-filed comments to the extent practicable, and make any necessary amendments as appropriate.
In developing this IFR, PHMSA considered the findings of lithium battery research conducted by the Federal Aviation Administration's William J. Hughes Technical Center (FAA Technical Center), the National Transportation Safety Board (NTSB), and several other well-respected academic sources on lithium batteries and their hazards. The FAA Technical Center's research found that lithium batteries subject to certain conditions could result in adverse events, such as smoke and fire, that could impair the safe operation of the aircraft. Specifically, they found that in a lithium battery fire, flammable gases could collect, ignite, and ultimately exceed the capabilities of an aircraft's fire suppression system. The ICAO also recognized these dangers and enacted international regulations, which went into effect on April 1, 2016. The potential for a catastrophic loss of an aircraft, the need for harmonization of the HMR with emergency amendments to the ICAO Technical Instructions, and the statutory deadline in the FAA Reauthorization Act of 2018 provide compelling justification to immediately adopt these changes into the HMR without prior notice and comment.
A Regulatory Impact Analysis (RIA) is included in the docket for this rulemaking and supports the amendments made in this IFR. PHMSA examined the benefits and costs of these rulemaking provisions using the post-ICAO baseline  as shown in the analysis below. Table 1 shows the costs by affected section and rulemaking provision over a 10-year period, discounted at a 7 percent rate:
Table 1—Summary of Benefits and Costs for Lithium Battery Provisions—Post ICAO
ProvisionBenefitsUnquantified costs10-Year quantified cost (7%)
State of Charge• Limits the volume of flammable gases emitted by lithium ion cells propagated in a thermal runaway • Results in a less energetic thermal runaway event if one should occur • Reduces the likelihood of thermal propagation from cell to cell • Harmonization facilitates international trade by minimizing the burden of complying with multiple or inconsistent safety requirements (although currently domestic shippers and carriers have the option to voluntarily comply with ICAO requirements). Consistency between regulations reduces compliance costs and helps to avoid costly frustrations of international shipments• Potential changes in manufacturing procedures to ensure compliance with state of charge provision • Reevaluation of management practices and potentially instituting changes to avoid or lessen supply chain impacts such as reduced shelf life of batteries and battery quality issues • Additional time for end users needed to charge the batteries from 30 percent state of charge or less instead of the typical levels of 40 percent or 50 percent at which manufacturers currently set the state of charge$2,304,551 These estimates include only the cost for entities to apply for permission to ship batteries at higher charge levels.
Consignment Limit• Reduces the risk of fire from shipping large quantities of excepted batteries that were previously being consolidated in overpacks, pallets, in single-unit load devices and single aircraft cargo compartments. • Reduces the propensity for large numbers of batteries or packages shipped in accordance with regulatory exceptions. • Harmonization facilitates international trade by minimizing the burden of complying with multiple or inconsistent safety requirements (although currently domestic shippers and carriers have the option to voluntarily comply with ICAO requirements). Consistency between regulations reduces compliance costs and helps to avoid costly frustrations of international shipments.• Costs due to modal shift that might occur from air transport to ground or marine transport due to higher shipping costs by air. The end receivers may be inconvenienced by longer shipping times that imply less prompt access to goods purchased.$44,328,936 Costs include additional hazard communication and employee training.
Lithium Battery Prohibition as Cargo on Passenger Aircraft• Safety benefits expected to be low or none given evidence of pre-IFR compliance. • Eliminates the risk of an incident induced by lithium ion batteries shipped as cargo in a passenger aircraft. • Eliminates the risk of a fire exacerbated by the presence of lithium ion batteries involving the cargo hold of a passenger aircraft. • Harmonization facilitates international trade by minimizing the burden of complying with multiple or inconsistent safety requirements (although currently domestic shippers and carriers have the option to voluntarily comply with ICAO requirements). Consistency between regulations reduces compliance costs and helps to avoid costly frustrations of international shipments• Potential additional costs to air carriers transporting cargo shipments of lithium ion batteries on cargo planes instead of passenger aircraft. They vary for each air carrier based on the size of the airline and the areas they service, the availability of cargo-only aircraft fleet, the capacity usage and cargo volume availability of cargo aircraft fleet, and the volume of lithium ion batteries they were transporting by passenger airplanes. • Cost due to modal shift that might occur as higher costs to ship by air may induce shippers to send by ground and marine transportation. The end receivers may be inconvenienced by longer shipping times that imply less prompt access to goods purchased. This can have potential impacts on rural and remote communities not serviced daily by cargo aircraft or only serviced by passenger aircraft. For customers needing lithium batteries used in devices, other than medical devices, the delays in the delivery of the required batteries could result in a range of consequences depending on their intended need.Impact expected low given evidence of pre-IFR compliance.
Total10-Year: $46,633,487 Annualized: $6,639,559
Based on the analysis described in the RIA, at the mean, PHMSA estimates the present value costs about $46.6 million over 10 years and about $6.6 million annualized (at a 7 percent discount rate).
While PHMSA examined the benefits and the costs of the provisions of this rulemaking using the post-ICAO baseline as the basis for the analysis, we acknowledge that using the pre-ICAO baseline  would produce different cost and benefit figures. That said, given the significant data uncertainties regarding pre-ICAO baseline and operational practices, PHMSA was unable to completely quantify the pre-ICAO baseline. PHMSA has provided a discussion of these qualitative benefits and costs. For more detail on cost and benefits of the pre-ICAO baseline, see “Section 11 Alternative Baseline Analysis” of the RIA included in the docket for this rulemaking. PHMSA requests public comment on the RIA as it applies to the benefits and costs under both baselines.
II. Current Lithium Battery Transportation Requirements
Lithium cells and batteries fall into one of two basic categories: lithium metal, including lithium alloy (also known as primary lithium batteries), and lithium ion, including lithium ion polymer (also known as secondary lithium batteries). As the name indicates, lithium metal cells and batteries contain a small amount of metallic lithium or a lithium alloy. Lithium metal batteries are mostly non-rechargeable and are often used in medical devices, computer memory, and as replaceable batteries (AA and AAA size) suitable for electronic devices. The lithium content in these cells and Start Printed Page 8009batteries ranges from a fraction of a gram to a few grams and typical geometries include coin cells, cylindrical, and rectangular. Conversely, lithium ion cells and batteries contain a lithium compound (e.g., lithium cobalt dioxide, lithium iron phosphate). Lithium ion batteries are generally rechargeable and are most often found in portable computers, mobile phones, and power tools. Common configurations are cylindrical and rectangular. For the purposes of the HMR, the size of lithium ion cells and batteries is measured in Watt-hours (Wh).
Lithium cells and batteries are capable of efficiently storing large amounts of energy and have a higher specific energy (capacity) and energy density relative to other battery chemistries, such as alkaline, nickel metal hydride (NiMH), and nickel cadmium (NiCd). However, when subjected to mechanical abuse, internal or external short circuit, overcharge, or excessive heat, a lithium cell or battery is susceptible to thermal runaway, which is a chain reaction leading to self-heating and release of stored energy.[3 4] A lithium ion cell sufficiently heated can induce a thermal runaway event. Cells in thermal runaway can release excessive heat (up to 1400 °F (760 °C)), as well as flammable and toxic gases, and the heat from a single cell in thermal runaway can spread to adjacent cells in a battery or package.[5 6] This cascading effect, or spreading, (hereafter referred to as propagation) increases the potential ignition of adjacent combustible materials. In addition, the pressure inside a cell can increase, causing the cell to rupture and resulting in a projectile hazard and the release of flammable gases. Vented gases from only a small number of cells, if ignited, can result in a pressure pulse that can compromise the fire suppression capability of an aircraft cargo compartment. Based on FAA Technical Center data, the volume of flammable cell gas ignited to produce a 1.2 psi pressure rise corresponded to only 6.4 cells at 100 percent state of charge or 20 cells at 50 percent state of charge. Cargo compartments are only designed to withstand an approximate 1-psi pressure differential.
Triggering events to a thermal event include external short circuits, mechanical damage, exposure to heat, and manufacturing defects that result in an internal short circuit. While the likelihood of a thermal event occurring on an aircraft is low, the consequences of an event are high. The inability of the aircraft fire suppression systems to address lithium cell or battery fires poses an unacceptable safety risk, even if the likelihood of an event is low.
The HMR include separate entries for lithium metal batteries (UN3090), lithium metal batteries packed with equipment (UN3091), lithium metal batteries contained in equipment (UN3091), lithium ion batteries (UN3480), lithium ion batteries packed with equipment (UN3481), and lithium ion batteries contained in equipment (UN3481). Both the HMR and the 2015-2016 ICAO Technical Instructions already prohibit the transport of lithium metal batteries (UN3090) as cargo on passenger aircraft.[8 9]
The requirements for the transport of lithium batteries are based on risk and are designed to work together to create layers of safety, accounting for battery chemistry (lithium metal and lithium ion), battery size, and package quantity. Lithium batteries are subject to design type testing, various hazard communication, and packaging requirements. Design testing serves to ensure that batteries are able to withstand certain transport and abuse conditions without hazardous consequences. However, the tests are not meant to ensure that lithium batteries are safe in all conditions, such as extreme heat or damage. Lithium cells and batteries may still be subject to mishandling in transport that can result in severe mechanical damage or short circuits. This hazard drives the need for protection against damage and short circuits, as well as the use of strong outer packaging. Hazard communication (i.e., package marks, labels, and shipping documents) serves to alert transport workers throughout the supply chain of the presence of lithium cells or batteries, the need to handle them properly, and the measures to take in the event of an emergency. Hazmat employees must be trained in accordance with the HMR, ensuring that personnel responsible for preparing for transport and transporting do so in compliance with the HMR and maintain safety throughout the supply chain.
In § 173.185, PHMSA sets forth general requirements for lithium cells and batteries, such as United Nations (UN) design testing requirements, packaging requirements, and provisions for small cells and batteries. Unless otherwise specified in § 173.185, the hazard communication and training requirements are located in part 172 of the HMR.
Section 173.185(c) of the HMR describes provisions for the carriage of up to 8 small lithium cells or 2 small lithium batteries per package with alternative hazard communication that replaces the Class 9 label with a lithium battery mark that communicates the presence of lithium batteries and indicates (1) that the package is to be handled with care, (2) that a flammable hazard exists if the package is damaged, and (3) that special procedures must be followed in such event that the package is damaged (i.e., inspection and repacking (if necessary), as well as a telephone number for additional information). Further, when used, an air waybill must indicate compliance with the provisions of § 173.185(c) or the applicable ICAO packing instruction. Consignments of lithium batteries that comply with these provisions are provided alternatives from the standard hazard communication and relief from the acceptance checks that air carriers use to recognize and accept or reject hazardous materials as appropriate. Start Printed Page 8010Currently, § 173.185(c) does not place a limit on the number of packages containing such lithium batteries permitted in overpacks, pallets, single unit load devices, or single aircraft cargo compartments. This condition allows large numbers of packages of small cells and batteries to be placed near each other without standard declaration to the air carrier or pilot in command.
III. Need for the Rule
Lithium batteries are increasingly prevalent in today's consumer market due to their ability to store substantially more energy than other batteries of the same size and weight. This trend toward lithium ion battery technology has continued over the last decade as illustrated by an increase in lithium ion cell production from approximately 3 billion cells in 2007 to over 7 billion lithium ion cells produced in 2017. PHMSA identified a total of 39 incidents in air cargo transportation between 2010 and 2016 with 13 of these incidents involving lithium batteries and smoke, fire, extreme heat, or explosion that would have been affected by this rulemaking. Many of these incidents were identified at an air cargo sort facility either before or after a flight. In at least one instance, packages of lithium ion cells were found smoldering in an aircraft unit load device during unloading. This indicates that the initial thermal runaway likely occurred while the shipment was on the aircraft. PHMSA also notes three aircraft accidents in 2007, 2010, and 2011 where lithium ion batteries transported as cargo were suspected as either the cause or a factor that increased the severity of the fire. Collectively these accidents resulted in the complete loss of all three aircraft and four lives. These accidents highlight the potential for lithium batteries to contribute to an incident resulting in loss of life and/or loss of aircraft.
Testing conducted by the FAA Technical Center to assess the flammability characteristics of lithium ion rechargeable cells and the potential hazard associated with shipping them on transport aircraft confirmed that fires involving lithium batteries sometimes include a mechanical energy release that can create projectile hazards; thermal runaway from a single cell that can spread to adjacent cells and packages; and the venting of flammable gases that can occur even when the fire is suppressed. Cell failure resulting in a mechanical energy release was observed during testing and was more energetic at 100 percent state of charge relative to cells tested a lower state of charge. However, a state of charge at less than 100 percent still has the potential to result in a mechanical energy release. For example, the FAA testing conducted in 2010 using lithium ion 18650 LiCoO2 cells at a 50 percent state of charge resulted in all 100 cells experiencing thermal runaway. Testing conducted by the NTSB confirmed the potential for fire and projectile hazards and further concluded that aircraft unit load device design can impact the time it takes to detect a fire originating from inside a cargo container. Additionally, the FAA testing determined that Halon 1301, the fire-suppressant agent used in Class C cargo compartments, could suppress the electrolyte and burning packaging fires, but it had no effect on stopping the propagation of thermal runaway from cell to cell. See 14 CFR 25.857for aircraft cargo compartment classification, including Class C. Halon 1301 was also shown to be ineffective in suppressing an explosion of the flammable gases vented from lithium ion cells during thermal runaway.
A. FAA Technical Center Testing
The FAA Technical Center issued a series of test reports in 2004, 2006, 2010, and 2014 that characterized the hazards posed by lithium cells and batteries transported as cargo on aircraft and the effectiveness of aircraft fire suppression agents, packagings, and packaging configurations. Specifically, the FAA Technical Center tested the ability of various fire extinguishing agents and fire resistant packagings to control fires involving lithium batteries. This testing revealed that: (1) The ignition of the unburned flammable gases associated with a lithium cell or battery fire could lead to a catastrophic loss of the aircraft; (2) the current design of the Halon 1301 fire suppression system  in a Class C cargo compartment in passenger aircraft is incapable of preventing such an explosion; and (3) the ignition of a mixture of flammable gases could produce an over pressure, which would dislodge pressure relief panels, allow leakage of Halon from the associated cargo compartment, and compromise the ability of fire suppression systems to function as intended. As a result, the smoke and fire can spread to adjacent compartments and potentially compromise the entire aircraft. Moreover, the FAA testing concluded neither oxygen starvation through depressurization in the case of cargo aircraft nor common shipping containers (e.g., unit load devices) is effective in containing or suppressing a lithium cell or battery fire.
When controlling lithium battery fires, aircraft fire extinguishing agents must both extinguish the electrolyte fire and cool remaining cells to stop the propagation of thermal runaway. Gaseous agents (such as Halon) are somewhat effective against lithium ion battery fires; however, while Halon is effective in extinguishing the electrolyte fire and nearby combustible materials such as packaging, it has no effect in stopping the propagation of thermal runaway from cell to cell. Conventional fiberboard packagings initially protect cells and batteries but eventually ignite and add to the fire load. Special packagings originally designed for chemical oxygen generators are effective in containing a fire from burning lithium ion cells but allow smoke and fumes to escape the package. Currently available fire containment covers (FCC) and fire resistant containers (FRC) that suppress fires by means of oxygen starvation are not effective in controlling lithium ion cell or battery fires. The fire load for each test consisted of 5,000 lithium ion 18650 LiCoO2 cells, with the balance of the interior volume containing the standard fire test load of cardboard boxes filled with shredded paper. The state of charge was measured to be around 40 percent. The FCCs tested were unable to contain a fire involving lithium ion batteries and flames escaped from under the cover, while tests on the FRCs resulted in explosions that were caused by the ignition of accumulated flammable gases vented from burning cells and/or batteries.
The 2004 tests concluded that the presence of a consignment of lithium metal batteries can significantly increase the severity of an in-flight cargo compartment fire and that Halon 1301 is ineffective in such occurrences.19 Start Printed Page 8011Furthermore, the report stated that the ignition of a lithium metal battery releases burning electrolytes and a molten lithium spray capable of perforating the aircraft cargo compartment liners, while also generating a pressure pulse that can dislodge the cargo compartment pressure relief panels. The dislodged pressure relief panels allow the Halon 1301 fire suppressant to leak out, reducing its effectiveness and permitting the fire to spread beyond the cargo compartment. These test results identified that the Halon fire suppression system required on passenger aircraft could not effectively suppress a fire involving lithium metal batteries, but they were inconclusive with respect to lithium ion batteries. Based on the 2004 FAA Technical Center test results, PHMSA published an IFR in December 2004 [69 FR 75208] prohibiting the transport of lithium metal batteries as cargo on passenger aircraft and indicated plans for the continued assessment of the hazards associated with lithium ion batteries in transportation. ICAO later aligned with the HMR.
The 2006 tests concluded that the Halon fire suppression system is effective in suppressing a fire arising from lithium ion batteries. Cells continued to vent due to the air temperature but did not ignite in the presence of Halon.
The 2010 tests investigated the ability of various packages and shipping configurations to contain the effects of lithium battery fires and prevent the propagation of thermal runaway. The baseline for these tests was a common shipping configuration for lithium ion cells consisting of a fiberboard box containing 100 cells with fiberboard separators. A single cell was removed from the package and replaced with a cartridge heater to initiate thermal runaway. The cartridge heater was activated at time zero, and its temperature reached 1000 °F (538 °C) at the 9-minute mark and peaked at 1250 °F (677 °C) at approximately 19 minutes, at which point the power to the cartridge heater was shut off. The fiberboard box began to smoke 8 minutes into the test and then caught fire at the 11-minute mark. As cells went into thermal runaway, strong torch flames erupted from the box as electrolytes were vented and ignited by the burning fiberboard. The fire continued to burn vigorously for 45 minutes until all of the cells were consumed. Data was collected until all thermocouples returned to near ambient temperature. In a subsequent test, the fiberboard separators were replaced with a fiberglass material used as a flame barrier in aircraft thermal acoustic insulation that was cut to the same dimensions as the fiberboard separators. The fiberglass separators were not successful in controlling the propagation of thermal runaway. In additional tests, the fiberboard dividers were replaced with those coated with intumescent paint or aluminum foil. This modification only delayed adjacent batteries from being driven into thermal runaway and did not prevent its propagation. Finally, the FAA Technical Center evaluated the ability of an overpack originally designed for the transport of chemical oxygen generators to protect against a lithium ion battery fire initiated from a single cell. This package consists of a fiberboard container with a foil and/or ceramic insulator that meets the requirements of HMR provisions found in appendix D to part 178—Thermal Resistance Test and appendix E to part 178—Flame Penetration Resistance Test.A fiberboard package with 100 cells and fiberboard separators was placed into the overpack. Thermal runaway was initiated and allowed to propagate until all cells were consumed. The overpack successfully contained the fire but allowed smoke and fumes to escape due to increased pressure. The chemical oxygen generator overpack standard did not account for the accumulation of vented flammable gases and was therefore not effective in containing lithium ion battery fires.
In 2013, the FAA Technical Center conducted a series of tests to examine the effectiveness of fire extinguishing agents for suppressing lithium metal and lithium ion battery fires and preventing thermal runaway propagation (DOT/FAA/TC-13/53). These tests used five 2600mAh lithium ion 18650 LiCoO2cells charged to 50 percent capacity. Aqueous agents were the most effective at preventing thermal runaway propagation. The FAA Technical Center further tested the effectiveness of passive protection of lithium battery shipments and published a report in February 2016. For these tests, a packet of water placed above the cells in a package containing 16 lithium ion 18650 LiCoO2 cells (at 50 percent state of charge) was the most effective method of stopping thermal runaway propagation, aside from a lowered state of charge. Early tests with small numbers of cells predicted that the Halon 1301 extinguishing agent would suppress the open flames but not prevent the propagation of thermal runaway from cell to cell. Further tests confirmed that, in some instances, the Halon fire suppression system was unable to mitigate a fire involving lithium ion batteries effectively. These tests were conducted with fiberboard boxes containing 100 lithium ion 18650 LiCoO2 cells. A single cell was removed and replaced with a cartridge heater to simulate a cell in thermal runaway. The test chamber was flooded with a 6 percent Halon 1301 concentration at the first indication of open flames. The agent extinguished the open flame and prevented open flames for the duration of the test. Thermal runaway continued to propagate throughout the box until all cells were consumed. Tests on FCCs and FRCs that suppress fires by means of oxygen starvation showed that these fire suppression methods are not effective in controlling lithium ion cell or battery fires. The fire load for these tests consisted of 5,000 lithium ion 18650 LiCoO2 cells, with the balance of the interior volume containing the standard fire test load of cardboard boxes filled with shredded paper. The state of charge was measured to be around 40 percent. Since Halon has no cooling effect, the temperatures found in a suppressed cargo fire were high enough that cells continued to vent, creating an ignition source for the accumulated gas. The buildup and subsequent ignition of these gases ruptured the container. The container and its contents were destroyed by the ensuing fire.
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In July 2015, in response to the FAA Technical Center testing, two major aircraft manufacturers issued notices to aircraft operators warning of these hazards and supporting a prohibition on the carriage of high-density packages of lithium ion batteries on passenger aircraft until safer methods of transport were implemented.[25 26 27] Additionally, the aircraft manufacturers recommended that operators who choose to carry lithium batteries as cargo on cargo aircraft conduct a safety risk assessment that considers specific criteria listed in the July 2015 notices. While the likelihood of a cargo fire involving lithium batteries is low, the potential for catastrophic consequences including loss of life and loss of aircraft results in an unacceptable safety risk under the existing regulations.