Exploding Takata inflators caused the largest series of auto recalls in U.S. history, with at least 63 million inflators recalled.
Takata used volatile ammonium nitrate to create a small explosion to fill air bags in a crash.
NHTSA hired air bag chemical expert Harold Blomquist, who holds 25 air bag patents, to review the data, and he concluded that the GM air bags were similar to other Takata inflators that had exploded.
Test results for the GM inflators included abnormally high-pressure events “indicative of potential future rupture risk,” NHTSA said in documents.
“These findings illustrate that GM's inflators have a similar, if not identical, degradation continuum” to other Takata inflators that have exploded, the agency wrote.