โ™ป๏ธap environmental science review

Parts per Million (PPM)

Written by the Fiveable Content Team โ€ข Last updated August 2025
Verified for the 2027 exam
Verified for the 2027 examโ€ขWritten by the Fiveable Content Team โ€ข Last updated August 2025

Definition

PPM is a unit of measurement used to express the concentration of one substance in a solution or mixture. It represents the number of parts of a particular substance per million parts of the whole.

AP course connection

Topic 8.2: 8.2 Human Impacts on Ecosystems

Unit 8

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