Section 243.123  Carbon Monoxide

a)         Standards.  The ambient air quality standards for carbon monoxide are:

1)         A maximum 8-hour concentration not to be exceeded more than once per year of 10 milligrams per cubic meter (9 ppm); and,

2)         A maximum 1-hour concentration not to be exceeded more than once per year of 40 milligrams per cubic meter (35 ppm).

b)         Measurement Method.  For determining conformance with the carbon monoxide air quality standard, carbon monoxide shall be measured by the nondispersive infrared spectrometry technique as described in 40 CFR 50, App. C (1982), 36 Fed. Reg. 22,391, November 25, 1971, or by an equivalent method approved by the Agency.