What does ‘parts per million’ mean or measure? Welcome to EnglishwithJeff.com › Forums › Language Questions › What does ‘parts per million’ mean or measure? This topic is empty. Viewing 1 post (of 1 total) Author Posts March 8, 2021 at 9:26 am #1932 Jeff LebowKeymaster It’s a common way to measure concentration. https://www.greenfacts.org/glossary/pqrs/parts-per-million-ppm.htm https://en.wikipedia.org/wiki/Parts-per_notation https://writebetter.io/examples/parts+per+million/ Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In