There have been efforts to evaluate cleaning methods for respirators in emergency shortages, although there is concern that this may reduce filter performance, or affect mask fit by deforming the mask.[27][28][29] Duke University researchers have published a method for cleaning N95 respirators without damaging them using vaporized hydrogen peroxide to allow reuse for a limited number of times.[30][31][32] Battelle received an Emergency Use Authorization from the U.S. Food and Drug Administration to sterilize N95 masks.[33][34]