(a) Compliance with the diesel fuel content requirements of this division must be determined by applying the appropriate test methods and procedures specified in the active version of American Society for Testing and Materials (ASTM) D975 (Standard Specification for Diesel Fuel Oils), or by applying the supplementary test methods and procedures specified in paragraphs (1) - (5) of this subsection, as appropriate.
  (1) The aromatic hydrocarbon content may be determined by the active version of ASTM Test Method D5186 (Standard Test Method for Determination of Aromatic Content and Polynuclear Aromatic Content of Diesel Fuels and Aviation Turbine Fuels by Supercritical Fluid Chromatography). The following correlation equation must be used to convert the supercritical fluid chromatography (SFC) results in mass percent to volume percent: aromatic hydrocarbons expressed in percent by volume = 0.916 x (aromatic hydrocarbons expressed in percent by weight) + 1.33.
  (2) The polycyclic aromatic hydrocarbon (also referred to as polynuclear aromatic hydrocarbons or PAH) content may be determined by the active version of ASTM Test Method D5186 (Standard Test Method for Determination of Aromatic Content and Polynuclear Aromatic Content of Diesel Fuels and Aviation Turbine Fuels by Supercritical Fluid Chromatography). The correlation equation specified in paragraph (1) of this subsection must be used to convert the SFC results in mass percent to volume percent.
  (3) The nitrogen content may be determined by the active version of ASTM Test Method D4629 (Standard Test Method for Trace Nitrogen in Liquid Petroleum Hydrocarbons by Syringe/Inlet Oxidative Combustion and Chemiluminescence Detection).
  (4) The American Petroleum Institute (API) gravity index may be determined by the active version of ASTM Test Method D287 (Standard Test Method for API Gravity of Crude Petroleum and Petroleum Products (Hydrometer Method)).
  (5) The distillation temperatures may be determined by the active version of ASTM Test Method D86 (Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure).
(b) Modifications to the testing methods and procedures in this section may be approved by the executive director after consultation with and agreement by the United States Environmental Protection Agency (EPA).
(c) The executive director, upon application, may approve alternative diesel fuel formulations as prescribed under §114.312(d) of this title (relating to Low Emission Diesel Standards) that may be used to satisfy the low emission diesel fuel (LED) requirements specified in §114.312(a) of this title if the applicant has demonstrated to the satisfaction of the executive director and the EPA in accordance with the procedures specified in paragraph (1) of this subsection that the alternative diesel fuel formulation will achieve equivalent or better reductions in emissions of nitrogen oxides (NOX ).
  (1) The applicant shall submit documentation demonstrating that the applicable fuel properties of the alternative diesel fuel formulation demonstrate at least a 5.5% reduction in NOX emissions from on-road diesel fuel for the year 2007, and at least a 6.2% reduction in NOX emissions from non-road diesel fuel, using the Unified Model as described in the EPA staff discussion document, Strategies and Issues in Correlating Diesel Fuel Properties with Emissions, Publication Number EPA420-P-01-001, published July 2001.
  (2) For alternative diesel fuel formulations that achieve emission reductions as demonstrated in accordance with the criteria specified in paragraph (1) of this subsection, the applicant shall provide documentation to the executive director upon application that includes the cetane number, aromatic hydrocarbon content, specific gravity, and the temperature corresponding to the 50% point on the distillation curve in degrees Fahrenheit (T50) of the alternative diesel fuel formulation for which the applicant is requesting approval as determined in accordance with the test methods and procedures specified in subsection (a) of this section.
  (3) If the alternative diesel fuel formulation has been demonstrated to the satisfaction of the executive director and the EPA to achieve comparable or better reductions in emissions of NOX in accordance with paragraph (1) of this subsection, then the executive director may issue a notice of approval indicating that the alternative diesel fuel formulation may be used to satisfy the LED requirements of §114.312(a) of this title.
    (A) The approval notification must identify the specifications of the alternative diesel fuel formulation as approved under this subsection by listing the cetane number, aromatic hydrocarbon content, specific gravity, and the temperature corresponding to the 50% point on the distillation curve in degrees Fahrenheit (T50) of the alternative diesel fuel formulation as documented in paragraph (2) of this subsection.
    (B) The approval notification must assign an identification number to the specific approved alternative diesel fuel formulation.
(d) Approval of any additive-based alternative diesel fuel formulation as prescribed under this section prior to April 1, 2012, and thereafter, is subject to revocation if the executive director determines that the composition of the additive component of the approved alternative diesel fuel formulation has been altered so that it no longer matches the composition of the additive as originally approved. If the executive director revokes the approval of an additive-based alternative diesel formulation, producers using the alternative diesel formulation to satisfy the LED requirements of §114.312(a) of this title must discontinue all use of the alternative diesel formulation within 45 days of the date of revocation.
(e) All alternative diesel fuel formulations approved by the executive director as prescribed under this section prior to April 1, 2012, may continue to be used to comply with the provisions specified in this division.

Source Note: The provisions of this §114.315 adopted to be effective May 11, 2000, 25 TexReg 4030; amended to be effective January 18, 2001, 26 TexReg 328; amended to be effective March 31, 2005, 30 TexReg 1773; amended to be effective May 17, 2006, 31 TexReg 3881; amended to be effective September 13, 2012, 37 TexReg 7181