Air quality rating sacle?

Question

What is the meaning and difference in the air codes issued for air?

For example what is the difference between a code red and purple or green and Orange?

I've looked on the Department of Environmental Quality web site and can not find it any where.

Answer 1

Try this link from the National Weather Service, it explains the different categories:

http://www.nws.noaa.gov/ost/air_quality/...

There's also information on Wikipedia:

http://en.wikipedia.org/wiki/Air_quality