Federal regulators want manufacturers of seat and shoulder belt positioning devices to warn customers that the equipment should not be used on young children.
Officials at the National Highway Traffic Safety Administration proposed the warning labels Tuesday to make clear the possibility that seat belt adjusters could cause greater crash injuries in children under age 6 than they otherwise would incur.
"This proposal, if adopted, would help parents provide for the safety of children," said Transportation Secretary Rodney Slater.
Millions of after-market, seat-belt-positioning devices have been sold in the United States in the last decade. The devices often use cloth or clips to lower the shoulder belt for children or small adults so the belt does not ride up on their necks or heads.
However, unlike child seats, they are not regulated by any federal motor vehicle safety standard.
In particular, agency officials worry that belt-positioning devices may cause the lap belt to rise up in a crash and rest above the child's hips to increase potential for abdominal injury. They are seeking public comment on whether the warning label also should tell parents to ensure that a belt-adjuster positions the lap belt low across the child's hips rather than on the abdomen.
Robert Capps, chief executive of Blue Ridge International Products Co., the largest manufacturer of seat belt adjusters in the United States, welcomed the idea of warning labels.
Blue Ridge makes and sells SafeFit, a triangular nylon pouch that fits over the belts near the buckle.
Capps said SafeFit always has recommended using the product for children over 50 pounds, or about age 6.
Since 1990, more than 4-million of the devices have been sold in the United States and 23 other countries, Capps said. About a half-dozen other companies sell seat belt adjusters.