SAN DIEGO COUNTY AIR POLLUTION CONTROL DISTRICT

RULE 127 - EPISODE CRITERIA LEVELS
(Rev. Effective 9/17/91)

The concentrations of air pollutants at which the various episode stages are declared are given in the table below:

Pollutant

Averaging Time

Health Advisory*

Stage 1*

Stage 2*

Stage 3*

Ozone

1 hr.

0.15 ppm

(295 µg/m3)

or more

0.20 ppm

(399 µg/m3)

or more

0.35 ppm

(698 µg/m3)

or more

0.50 ppm

(998 µg/m3)

or more

Carbon Monoxide

1 hr.

40 ppm

(47 mg/m3)

or more

40 ppm

(47 mg/m3)

or more

75 ppm

(87 mg/m3)

or more

100 ppm

(116 mg/m3) or more for 1 hr and predictged to persist for at least 1 additional hr.

Carbon Monoxide

4 hrs

25 ppm

(29 mg/m3) or more

25 ppm

(29 mg/m3) or more

45 ppm

(50 mg/m3)

or more

60 ppm

(70 mg/m3)

or more

Carbon Monoxide

8 hrs

15 ppm

(17 mg/m3)

or more

15 ppm

(17 mg/m3)

or more

30 ppm

(35 mg/m3)

or more

40 ppm

(47 mg/m3)

or more