This page lists every known solution for the clue “Parts Per Billion” in Crossword Challenge. Because this clue can appear in different puzzles (levels) with different required answers, we first list all the answers, then show which one appears in each puzzle below.
Parts Per Billion Crossword Challenge Answers (All Variants)
Ppb
If more than one answer is listed, open your puzzle page below to confirm the one used there.
All Known Answers for Parts Per Billion Clue
Where This Clue Appears
Last Checked: June 17, 2026