Regulators are expected to announce as early as Wednesday that at least 35 million additional airbags made by Takata will need to be fixed, according to a person briefed on the matter. This would more than double what is already the largest automotive recall in American history.

The airbags can unexpectedly explode, sending metal parts hurtling into the cabin. At least 11 deaths worldwide have been linked to the defect.

The expansion would bring the total of recalled Takata airbags to at least 63 million in the United States — possibly affecting nearly one in four of the 250 million vehicles on America’s roads.

At issue is Takata’s use of a compound called ammonium nitrate, which can become unstable over time or when it is exposed to moisture. Takata has wrestled with the makeup of the compound over the years, eventually adding a drying agent to make it more stable. The new recalls focus on airbags that do not have the drying agent.