WASHINGTON (Reuters) -- The top U.S. auto safety regulator said an expanded recall of Takata airbag inflators proposed by a key senator would not enhance public safety and complicate the process of replacing the equipment, the lawmaker revealed on Wednesday.
Sen. Bill Nelson of Florida, the top Democrat on the Commerce Committee that is investigating the recalls, said the National Highway Traffic Safety Administration should move faster in addressing the "recall fiasco."
Nelson on Feb. 23 urged NHTSA to recall all the suspect inflators. His demand came a day after Reuters reported that the agency was examining whether an additional 70 million to 90 million Takata inflators should be recalled because they might endanger drivers.
NHTSA Administrator Mark Rosekind, in a letter on Friday responding to Nelson, said such a massive new recall would "needlessly impose new hardships" on the supply of replacement parts for the 29 million Takata inflators already recalled.
Rosekind said a larger recall also would "increase uncertainty for consumers" and "significantly complicate" the process of supplying replacement parts on high-risk vehicles.
Nelson released the letter to the media on Wednesday.
"We need to end this confusion and I think the process has to begin with having NHTSA take a hard look at whether" to order a recall of up to 90 million Takata airbags with ammonium nitrate-based inflators.
"Ammonium nitrate seems to be the problem," he said of the volatile chemical used to inflate millions of Takata airbags.
Nelson said "ammonium nitrate should not be used as replacements for the old Takata inflators" or be put in new cars.
Under a November consent order, Takata must recall and replace all ammonium nitrate inflators by 2019 unless it could prove they are safe. NHTSA has repeatedly said it would quickly expand the recalls if it obtained evidence of additional issues.
NHTSA needs to "seriously consider a total recall of all Takata ammonium nitrate based inflators that are currently in vehicles," Nelson said.