When U.S. District Judge Kathryn Kimball Mizelle tossed out the federal government's transportation mask mandate on Monday, she relied in part on her interpretation of the term "sanitation."
The 10-letter word can be found in the Public Health Service Act, a sprawling 1944 law that gave the federal government certain powers to respond to public health emergencies.
The Biden administration relied on a piece of the Public Health Service Act to defend its COVID-19 mask mandate on airplanes and other forms of mass transit.
Specifically, the law says that if the government is trying to prevent the spread of communicable diseases, it can "provide for such inspection, fumigation, disinfection, sanitation, pest extermination, destruction of animals or articles found to be so infected or contaminated as to be sources of dangerous infection to human beings, and other measures, as in his judgment may be necessary."
The administration argued that masks qualified as "sanitation" under the law, but Mizelle disagreed, opting for a much narrower definition of the term that would exclude measures like face coverings. Legal experts say her interpretation missed the mark.
"If one of my students turned in this opinion as their final exam, I don't know if I would agree that they had gotten the analysis correct," said Erin Fuse Brown, a law professor at Georgia State University.
"It reads like someone who had decided the case and then tried to dress it up as legal reasoning without actually doing the legal reasoning," she added.
What counts as 'sanitation'?
In her opinion, Mizelle says that a common way judges decide the meaning of words in laws is to look up dictionary definitions that were contemporaneous with the passage of the law. In this instance, that's 1944.
Mizelle says "sanitation" could have been taken to mean either actively cleaning something or measures to keep something clean, but ultimately settles on the former definition.
"Wearing a mask cleans nothing. At most, it traps virus droplets," Mizelle wrote. "But it neither 'sanitizes' the person wearing the mask nor 'sanitizes' the conveyances."
Mizelle says her reading is bolstered by the fact that other words listed alongside "sanitation" in the 1944 law — such as "fumigation" or "pest extermination" — refer specifically to cleaning something or trying to wipe out a disease.
But Fuse Brown says that while this understanding of "sanitation" may be true for lay people, it's not how the term is used in the public health field or understood by the U.S. Centers for Disease Control and Prevention, which issued the mandate.
"Sanitation was just the old way in public health parlance of taking traditional public health steps to prevent the spread of disease," she said.
Fuse Brown points to the widespread mask-wearing during the 1918 influenza outbreak, which came roughly two and a half decades before the passage of the Public Health Service Act.
She suggested the opinion will make it harder for the Biden administration to control the spread of COVID-19.
"The reasoning is poor, but it also has really drastic and dire consequences for public health, which is the part that makes it not just a joke, but it actually makes it really frightening," she said.
The opinion could have lasting effects on the CDC's authority
Mizelle's opinion also restricts the CDC's ability to respond to public health emergencies in ways it deems appropriate, and if the opinion is upheld by a federal appeals court or the U.S. Supreme Court, legal experts warn it could hobble the government's ability to control future outbreaks.
"If this particular type of opinion took on greater precedential value as it rises up through the court system, if that happens, it's big trouble for CDC down the road," said James Hodge, a law professor at Arizona State University.
Mizelle substituted her own definition of "sanitation," Hodge said, brushing aside a legal norm known as "agency deference" that compels judges to yield to the interpretation of federal agencies when a law's language is unclear.
Mizelle also criticized the agency for not following standard rulemaking procedures before instituting the mandate. Hodge said she misunderstood how the federal government operates during a national public health emergency.
"This is really a serious deviation from not just what we're trying to do to protect the public's health, but a misstatement of federal authority in emergencies to a great degree," Hodge said.
Fuse Brown agreed, suggesting the opinion amounted to a "breathtaking amount of political judicial activism" that "should chill us all."
"Even if we're skeptical about agencies or even about Congress's ability to make good judgments in this ... time, we certainly do not want these decisions to be in the hands of a single unelected judge," she said.
NPR's Pien Huang contributed reporting to this story. Copyright 2022 NPR. To see more, visit https://www.npr.org.