Former Takata engineer Mark Lillie is on record warning Takata that the cheaper ammonium nitrate solution they used in their inflators in 1999 was dangerously unstable. Lillie worked as an engineering manager in Takata’s Moses Lake, Washington location. The ammonium nitrate solution can expand and contract in changing temperature.
“Tetrazole” is a more expensive and safer alternative used by air bag inflators. Takata switched to the cheaper ammonium nitrate.
Although Takata alleges ammonium nitrate solution is safe, they formed an independent review panel to investigate.
The replacement air bags in Takata air bag recalls have inflators with the same chemistry.