The number of vehicles recalled due to Takata's potentially deadly airbags is likely to get cut to 19 million: a 40% drop.

Federal regulators have sharply reduced the number of U.S. vehicles that will be covered by the recall of potentially deadly Takata airbags – but the total is still expected to be more than 19 million.

The Japanese supplier has been linked to a defect that can cause airbags in older vehicle to trigger with too much force, sending metal and plastic shrapnel spewing into the passenger compartment. At least eight deaths and more than 100 injuries have been linked to the problem.

After expanding the scope of the recall, the National Highway Traffic Safety Administration said 11 different automakers would have to replace inflators used in 34 million driver and passenger airbags. The agency has now reduced that by about 40%, to 23.4 million airbags used in 19.2 million vehicles.

There appear to be several reasons for the discrepancy. For one thing, a large number of vehicles using the suspect airbags turned out to have been sold outside the United States. Meanwhile some vehicles were counted twice, since they were equipped with Takata driver and passenger airbags.

Nonetheless, this is still believed to be one of, if not the largest recall in U.S. automotive history related to a single safety defect, according to industry observers. And the revised figure means more vehicles sold overseas may now be targeted for repairs by foreign government safety agencies.

So far, NHTSA estimates about 4.4 million Takata airbag inflators have already been replaced. But how long it will take to replace the rest is uncertain. The embattled Japanese supplier has been struggling to come up with the necessary replacement parts and some manufacturers, including Toyota, have begun looking for alternative sources.

The largest of the Japanese automakers last month asked safety supplier Nippon Kayaku Co. to provide up to 13 million replacement inflators in a deal that could be worth as much as $150 million, according to reports from Japan.

(Toyota looks for help to speed up Takata airbag recall. Click Here for more.)

While the number of vehicles covered by the Takata recall has dropped sharply, that could change, at least if two key automotive safety advocates in the U.S. Senate have their way.

Volkswagen recently notified the National Highway Traffic Safety Administration of a June incident involving a 2015 Tiguan SUV. After hitting a deer, one of its airbags exploded violently, nearly killing one of the occupants. The incident was significant for several reasons. First, it involved a recent model, rather than the older vehicles covered by the current Takata recalls.

(Click Here for details about how millions more vehicles could be added to a Takata-based recall.)

Secondly, the incident involved a side impact airbag, rather than the front airbags that have been so far targeted by NHTSA.

Two U.S. Senators, Connecticut’s Richard Blumenthal and Massachusetts Edward Markey, both Democrats, responded by calling for the recall of all vehicles using Takata airbags, including newer models.

(To see more about how Takata’s aging airbags may not be the only problem, Click Here.)

NHTSA is studying the incident and has not yet said if it will take any action.