Cite
 

Meaning of ambient air standard

am'bient air' stand"ard

Pronunciation: [key]
  1. the highest concentration of a specific air pollutant at a particular outdoor location, in a specified unit of time, that is not considered hazardous to humans: The ambient air standard for gas X is 3 parts per million per hour.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.