WASHINGTON -- Bush administration officials, in their last weeks in office, are pushing to rewrite a wide array of federal rules with changes or additions that could block product-safety lawsuits by consumers and states.

The administration has written language aimed at pre-empting product-liability litigation into 50 rules governing everything from motorcycle brakes to pain medicine. The latest changes cap a multiyear effort that could be one of the administration's lasting legacies, depending in part on how the underlying...