The fast-spreading Omicron variant stoked U.S. interest in better masks for children to ward off COVID-19, and that is adding fuel to an effort that could set the stage for domestic oversight of their quality. Adult N95 masks are federally regulated and considered a gold standard. For children, no comparable U.S.-regulated mask exists, and some concerned parents turned to kid-sized masks made to South Korea's KF94 or China's N95 standards instead.