Nissan is part of a massive 3-million vehicle recall for explosive, unstable airbag inflators manufactured by Takata.

To be clear, when an airbag deploys there’s always going to be a miniature explosion to make the inflation possible. But that explosion is controlled. In the case of Takata, the propellant used to make that explosion can deteriorate over time and cause dangerous –– possibly deadly –– issues when the airbag deploys:

Takata said the propellant wafers produced at a plant in Moses Lake, Washington, between April 13, 2000 and September 11, 2002, may have been produced with an inadequate compaction force. The propellant could deteriorate over time and cause too much combustion, which could cause the body of the inflator to rupture during air bag deployment.

When that inflator canister ruptures, metal shards can shoot out into the cabin. Most of the recalls are expected to begin in May, 2013.