State CO Standards:
20 ppm for 1 hour and
"9.0 ppm for 8 hours,"
neither to be exceeded.

6 ppm for 8 hours
"(Lake Tahoe Air Basin only),"
not to be equaled or exceeded.

National CO Standards:
35 ppm for 1 hour and
"9 ppm for 8 hours,"
neither to be exceeded more
than once per year.