EA21002
Desiccated Air Bag Inflator Rupture
From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.Consequently, all frontal inflators using propellant 2004 that do not contain a "desiccant" (a substance that traps and holds moisture) in US vehicles are under recall. These "non-desiccated" inflators either have been or are required to be replaced.In some cases, the remedy part for these recalled inflators was, or will be, an inflator using either propellant 2004 or 2004L that does contain a desiccant. None of these "desiccated" remedy parts (which were installed in older model year vehicles) are currently under recall for a degradation concern. Certain subsets of desiccated PSAN inflators using propellant 2004 for use as original equipment, however, have been recalled for a degradation concern. All Takata inflators produced with propellant 2004L contain desiccant, and none of these desiccated inflators using propellant 2004L are under recall for a degradation concern. There have been no reported field ruptures in any non-recalled desiccated PSAN inflators.It is understood that desiccants fully saturate at some threshold, at which point any additional moisture will not be captured. This means the degradation process observed in non-desiccated inflators using propellant 2004 may also occur in non-recalled desiccated inflators using propellant 2004, assuming additional moisture enters the inflator and high temperature cycling occurs. Based on available information, desiccant saturation can occur within the first five years in the worst environments, and the time required for full saturation is affected by multiple factors. While no present safety risk has been identified, further work is needed to evaluate the future risk of non-recalled desiccated inflators using propellant 2004.Three entities -- Takata (now known as TK Global), the Independent Testing Coalition, and Exponent -- have been studying the long-term behavior of Takata desiccated PSAN inflators using propellant 2004L (as well as 2004) in the presence of moisture and temperature cycling. The research efforts, which include development of predictive modeling techniques and field sample analysis, are ongoing. To date, none of the researchers have identified field evidence showing that propellant 2004L is undergoing a degradation process that leads to aggressive deployment and potential rupture. However, the time in service of such inflators remains short compared to that of the inflators using propellant 2004. Further study is needed to assess the long-term safety of desiccated inflators using propellant 2004L.The Office of Defects Investigation is opening this investigation to examine whether a safety defect related to propellant degradation exists in non-recalled desiccated PSAN frontal inflators manufactured by Takata. This investigation will require extensive information on Takata production processes and surveys of inflators in the field. Lists of recall actions that may have used desiccated PSAN inflators as remedy parts, as well as the makes and models originally manufactured with them, is available with the downloadable version of this document (see nhtsa.gov/recalls?nhtsaId=EA21002 -- note this information is subject to change/revision as the investigation proceeds). This investigation does not supersede EA15-001, which remains open.
EA15001
Air Bag Inflator Rupture
The Office of Defects Investigation (ODI) opened PE14-016 in June 2014 based on six inflator rupture incidents involving consumer owned vehicles produced by five vehicle manufacturers.All six vehicles were operated in Florida or Puerto Rico at the time of the rupture and for the majority of their service life, and were equipped with inflators produced by Takata, a tier-one supplier of automotive air bag systems.During the course of PE14-016, ODI determined that five additional vehicle manufacturers used inflators of a similar design and vintage also supplied by Takata. No evidence of field failures was found in vehicles produced by these five additional manufacturers.Nonetheless, at ODI's insistence, all 10 vehicle manufacturers initiated a regional recall within approximately two weeks of the opening of the investigation.The regions recalled initially included Florida, Puerto Rico, Hawaii, and the U.S. Virgin Islands, areas with high absolute humidity and climatic conditions believed to be a significant factor in the inflator ruptures.As part of the recall actions, inflators removed from remedied vehicles are to be returned to Takata for testing.Takata's initial test results on passenger inflators from remedied vehicles indicated a much higher than anticipated rupture frequency for inflators returned from Florida.Accordingly ODI requested all 10 manufacturers expand the regional recalls for passenger inflators to include other geographic areas where high absolute humidity conditions exist, including the Gulf States and other coastal areas.Takata's testing of the passenger inflators to date continues to indicate this geographic area as having the highest risk, with no ruptures occurring from inflators returned from outside the expanded recall regions.During PE14-016 four additional passenger inflator field events occurred, all in vehicles from the same expanded geographic region.Also during PE14-016 four additional driver inflator field events occurred including two in vehicles from regions not known for high absolute humidity, specifically California and North Carolina.Accordingly, ODI requested all five of the affected vehicle manufacturers currently using the subject Takata driver inflators expand to nationwide recalls.Significantly, neither of the affected vehicle manufacturers or Takata provided any explanation to account for these two driver air bag inflator ruptures outside the area of high absolute humidity.Takata testing of returned driver inflators indicates a lower rupture frequency as compared to passenger inflator testing.All test ruptures reported by Takata to date have occurred on inflators returned from high absolute humidity areas.The investigation now includes all manufacturers and vehicles known to be affected at this time.ODI's investigation will focus on, among other things, root cause analysis, other potential defect consequences, identification of affected vehicles scope, and adequacy of the remedy.The five ODI reports cited above can be reviewed online at http://www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification numbers: 10537899, 10568848, 10585224, 10605877, 10651492