PPM or Parts Per Million is a unit used to describe very small concentrations of a substance in a larger solution. PPM means 1 per every 1,000,000 or 1/1,000,000. What is PPM in Science? 8Qjr7j. Meaning of ppm in English. ppm. noun [ U ] uk / ˌpiː.piːˈem / us / ˌpiː.piːˈem /. Add to word list Add to word list. abbreviation for parts per million (= a unit for measuring the amount of a substance that is mixed with a liquid or another substance)

what is ppm stand for