R307-301-4. Sampling, Testing, and Oxygen Content Calculations

(1) For the purpose of determining compliance with the requirements of R307-301, the oxygen content of gasoline shall be determined by one or both of the two following methods.

(a) Volumetric Method. Oxygen content may be calculated by the volumetric method specified in the Environmental Protection Agency Guidelines for Oxygenated Gasoline Credit Programs under Section 211(m) of the Clean Air Act as Amended - Supplementary Information - Oxygen Content Conversions, published in the Federal Register on October 20, 1992.

(b) Chemical Analysis Method.

(i) Use the sampling methodologies detailed in 40 CFR Part 80 (1993), Appendix D, to obtain a representative sample of the gasoline to be tested;

(ii) Determine the oxygenate content of the sample by use of:

(A) the test method specified in ASTM Designation D4815-93, Testing Procedures--Method--ASTM Standard Test Method for Determination of C1 to C4 Alcohols and MTBE in Gasoline by Gas Chromatography,

(B) the test method specified in Appendix C of Environmental Protection Agency Guidelines for Oxygenated Gasoline Credit Programs under Section 211(m) of the Clean Air Act as Amended - Test Procedure Test for the Determination of Oxygenates in Gasoline as published in the Federal Register on October 20, 1992, or

(C) an alternative test method approved by the director.

(iii). Calculate the oxygen content of the gasoline sampled by multiplying the mass concentration of each oxygenate in the gasoline sampled by the oxygen molecular weight contribution of the oxygenate set forth in (3) below.

(2) All volume measurements required in R307-301-4 shall be adjusted to 60 degrees Fahrenheit.

(3) For the purposes of R307-301, the oxygen molecular weight contributions and specific gravities of oxygenates currently approved for use in the United States by the U.S. Environmental Protection Agency are the following:

TABLE

Specific Gravity and Weight Percent Oxygen of Common Oxygenates

oxygenate weight fraction specific gravity

                                   oxygen at 60 degrees F

ethyl alcohol 0.3473 0.7939

normal propyl alcohol 0.2662 0.8080

isopropyl alcohol 0.2662 0.7899

normal butyl alcohol 0.2158 0.8137

isobutyl alcohol 0.2158 0.8058

secondary butyl alcohol 0.2158 0.8114

tertiary butyl alcohol 0.2158 0.7922

methyl tertiary-butyl ether (MTBE) 0.1815 0.7460

tertiary amyl methyl ether (TAME) 0.1566 0.7752

ethyl tertiary-butyl ether (ETBE) 0.1566 0.7452

(4) Sampling, testing, and oxygen content calculation records shall be maintained for not less than two years after the end of each control period for which the information is required.

(5) Every refiner must determine the oxygen content of all gasoline produced for use in a control area by use of the methodology specified in (1) above. Documentation shall include the percent oxygen by weight, each type of oxygenate, the purity of each oxygenate, and the percent oxygenate by volume for each oxygenate. If a CAR or blender CAR alters the oxygen content of a gasoline intended for use within a control area during a control period, the CAR or blender CAR must determine the oxygen content of the gasoline by use of the methodology specified in (1) above.