The sulfur content of diesel fuel and diesel fuel additives is to be determined in accordance with this section.

(a) Sampling method. The applicable sampling methodology is provided in §80.330(b).

(b) Test method for sulfur—(1) For ECA marine fuel subject to the 1,000 ppm sulfur standard of §80.510(k), sulfur content may be determined using ASTM D2622 (incorporated by reference, see paragraph (e) of this section).

(2) For motor vehicle diesel fuel and diesel fuel additives subject to the 500 ppm sulfur standard of §80.520(c), and NRLM diesel fuel subject to the 500 ppm sulfur standard of §80.510(a)(1), sulfur content may be determined using ASTM D2622 (incorporated by reference, see paragraph (e) of this section).

(3) Beginning August 30, 2004, for motor vehicle diesel fuel and diesel fuel additives subject to the 15 ppm sulfur standard of §80.520(a)(1), sulfur content may be determined using any test method approved under §80.585.

(4) Beginning August 30, 2004, for NRLM diesel fuel and diesel fuel additives subject to the 15 ppm standard of §80.510(b), sulfur content may be determined using any test method approved under §80.585.

(c) Alternative test methods for sulfur—(1) Options for testing sulfur content of 1,000 ppm diesel fuel.

(i) For ECA marine fuel subject to the 1,000 ppm sulfur standard of §80.510(k), sulfur content may be determined using ASTM D4294, ASTM D5453, or ASTM D6920 (all incorporated by reference, see paragraph (e) of this section), provided that the refiner or importer test result is correlated with the appropriate method specified in paragraph (b)(1) of this section; or

(ii) For ECA marine fuel subject to the 1,000 ppm sulfur standard of §80.510(k), sulfur content may be determined using any test method approved under §80.585.

(2) Options for testing sulfur content of 500 ppm diesel fuel.

(i) For motor vehicle diesel fuel and diesel fuel additives subject to the 500 ppm sulfur standard of §80.520(c), and for NRLM diesel fuel subject to the 500 ppm sulfur standard of §80.510(a), sulfur content may be determined using ASTM D4294, ASTM D5453, or ASTM D6920 (all incorporated by reference, see paragraph (e) of this section), provided that the refiner or importer test result is correlated with the appropriate method specified in paragraph (b)(2) of this section; or

(ii) For motor vehicle diesel fuel and diesel fuel additives subject to the 500 ppm sulfur standard of §80.520(c), and for NRLM diesel fuel subject to the 500 ppm sulfur standard of §80.510(a), sulfur content may be determined using any test method approved under §80.585.

(d) Adjustment factor for downstream test results.

(1) Except as specified in paragraph (d)(1)(i) of this section, an adjustment factor of negative two ppm sulfur shall be applied to the test results from any testing of motor vehicle diesel fuel or NRLM diesel fuel downstream of the refinery or import facility, to account for test variability, but only for testing of motor vehicle diesel fuel or NRLM diesel fuel identified as subject to the 15 ppm sulfur standard of §80.510(b) or §80.520(a)(1).

(i) Prior to October 15, 2008 an adjustment factor of negative three ppm sulfur shall be applied to the test results, to account for test variability, but only for testing of motor vehicle diesel fuel or NRLM diesel fuel identified as subject to the 15 ppm sulfur standard of §80.510(b) or §80.520(a)(1).

(ii) [Reserved]

(2) In addition to the adjustment factor provided in paragraph (d)(1)(i) of this section, prior to September 1, 2006, an adjustment factor of negative 7 ppm shall be applied to the test results from any testing of motor vehicle diesel fuel downstream of the refinery or import facility, to facilitate the transition to ULSD fuel, but only for testing of motor vehicle diesel fuel identified as subject to the 15 ppm sulfur standard of §80.520(a)(1).

(3) In addition to the adjustment factor provided in paragraph (d)(1)(i) of this section, prior to October 15, 2006, an adjustment factor of negative 7 ppm shall be applied to the test results from any testing of motor vehicle diesel fuel at any retail outlet or wholesale purchaser-consumer facility, to facilitate the transition to ULSD fuel, but only for testing of motor vehicle diesel fuel identified as subject to the 15 ppm sulfur standard of §80.520(a)(1).

(e) Materials incorporated by reference. The published materials identified in this section are incorporated by reference into this section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that specified in this section, a document must be published in the Federal Register and the material must be available to the public. All approved materials are available for inspection at the Air and Radiation Docket and Information Center (Air Docket) in the EPA Docket Center (EPA/DC) at Rm. 3334, EPA West Bldg., 1301 Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number of the EPA/DC Public Reading Room is (202) 566-1744, and the telephone number for the Air Docket is (202) 566-1742. These approved materials are also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030 or go to http://www.archives.gov/federal__register/code__of__federal__regulations/ibr__locations.html. In addition, these materials are available from the sources listed below.

(1) ASTM International material. The following standards are available from ASTM International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-2959, (877) 909-ASTM, or http://www.astm.org:

(i) ASTM D2622-10, Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry, approved February 15, 2010.

(ii) ASTM D4294-10, Standard Test Method for Sulfur in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence Spectrometry, approved February 15, 2010.

(iii) ASTM D5453-12, Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by Ultraviolet Fluorescence, approved November 1, 2012.

(iv) ASTM D6920-13, Standard Test Method for Total Sulfur in Naphthas, Distillates, Reformulated Gasolines, Diesels, Biodiesels, and Motor Fuels by Oxidative Combustion and Electrochemical Detection, approved September 15, 2013.

(2) [Reserved]

[69 FR 39184, June 29, 2004, as amended at 70 FR 40896, July 15, 2005; 70 FR 70510, Nov. 22, 2005; 71 FR 16500, Apr. 3, 2006; 71 FR 25719, May 1, 2006; 73 FR 74357, Dec. 8, 2008; 75 FR 22971, Apr. 30, 2010; 79 FR 23653, Apr. 28, 2014]