“Big acronym in purifying filters” crossword clue

Reveal the answer to see why it works and where this clue has appeared before.HEPA is the answer to the New York Times crossword clue “Big acronym in purifying filters”. It was last seen in the puzzle of January 31, 2025, where it runs at 35 Across and fills 4 squares. It crosses 4 other entries in that grid — those are listed below and are the quickest way to confirm the letters you already have. This exact clue has run 3 times in NYT puzzles, first on January 31, 2025.