DETROIT >> Cars and trucks from the 2008 model year or older that were originally sold or registered in high-humidity areas along the U.S. Gulf Coast, as well as in Hawaii, are getting top priority for repairs as the government commences the massive Takata air bag inflator recall.

Honda Motor Co. leads all automakers with nine models designated as having the highest risk from air bag inflators that can explode with too much force, spewing metal shrapnel into drivers and passengers. Fiat Chrysler was second with seven.

On Nov. 3, the National Highway Traffic Safety Administration took control of the recall, which covers 19.2 million vehicles and is the largest in U.S. history. The agency wants to speed up the pace of repairs.

Even with government management, it could take as long as four years to replace all 23.4 million potentially faulty inflators.

High-priority models were announced as part of an agreement with Takata Corp. of Japan to pay up to a record $200 million penalty for deception in reporting problems and delays in fixing the inflators.

Cars and trucks from Honda and its Acura luxury brand on the high-risk list date to the 2001 model year. Vehicles from 11 other car and truck makers also are on the list.

In addition to Honda and Fiat Chrysler, Toyota had five vehicles in the top group, and Ford, Mazda, Nissan and Subaru tied with three each. Daimler vans, Mitsubishi and General Motors each had two models, while BMW and Daimler Trucks had one apiece.

In documents, NHTSA said cars and trucks in the “Priority One” group also have driver’s air bags that have been recalled, or both the driver and passenger inflators are faulty.

NHTSA defines the high-humidity region as Alabama, Florida, Georgia, Hawaii, Louisiana, Mississippi, Texas, Puerto Rico, American Samoa, Guam, Saipan and the U.S. Virgin Islands.

The agency set deadlines to make sure older cars in the risky areas get inflators first. Honda, which is Takata’s largest customer, has hired other inflator manufacturers to make replacement parts in addition to Takata. Honda and some other automakers have since said they won’t buy Takata inflators again.

Ammonium nitrate is a likely cause of Takata’s problems because it can degrade when exposed to airborne moisture and burn faster than expected. Takata has agreed to stop signing new contracts to make ammonium nitrate inflators.

All 12 automakers are required to contact other manufacturers to get inflators faster, and they must have a sufficient number of inflators to satisfy demand from “Priority One” vehicle owners by March 31, 2016. The recall of top-priority vehicles has to be completed by Dec. 31, 2017, while all vehicles in four priority groups must be fixed by the end of 2019.

A complete list of recalled vehicles can be found online at 808ne.ws/1kG5LSl.