The Law Dictionary

Your Free Online Legal Dictionary • Featuring Black’s Law Dictionary, 2nd Ed.

PARTS PER MILLION (PPM) Definition & Legal Meaning

Definition & Citations:

A concentrated volume of any gas, or part of it, or any other substance, compared to a million particles of liquid or air. A fair comparison can be that of 5 liters of water with an Olympic sized swimming pool.


This article contains general legal information but does not constitute professional legal advice for your particular situation. The Law Dictionary is not a law firm, and this page does not create an attorney-client or legal adviser relationship. If you have specific questions, please consult a qualified attorney licensed in your jurisdiction.