In 2000, the California Air Resources Board (CARB) adopted new standards that reduced emissions limits to 0.2 gram NOx for all new transit buses in the state beginning in 2007.
Now CARB, which is the only air quality regulating organization in the U.S. other than the EPA, is considering rolling back the standards to 1.2 grams NOx emissions or six times the pollution that the current rules would allow.










