Diesel Sulfur

More Information on Ultra Low Sulfur Diesel (ULSD)

Click here to view NPRA's Summary of the highway diesel final rule.

In February 2001, NPRA challenged specific provisions of the highway diesel rulemaking in the U.S. Court of Appeals for the District of Columbia Circuit. In general, NPRA argued that EPA's Highway Diesel Rules were unnecessarily stringent and could lead to supply shortages and price volatility. On May 3, 2002, the DC Court of Appeals upheld the Agency's rules.

EPA extended the transition period for highway ULSD in 2006 by 45 days for terminals and retail stations and temporarily allows up to 22 ppm sulfur as complying ULSD (70 FR 70498; 11/22/05). The Agency also temporarily relaxed the downstream sulfur tolerance from 2 to 3 ppm (71 FR 25706; 5/1/06). In addition, EPA has amended the highway and nonroad ULSD standards several times (see the timeline below); so it is challenging to keep up with the regulatory changes.

EPA and stakeholders have participated in three ULSD fuel workshops. To date, the Agency has released three versions of its ULSD question and answer document. The latest version is 136 pages long, an indication of how complicated these rules are and their impact on the entire diesel fuel distribution system.

For EPA Information:
http://www.epa.gov/otaq/highway-diesel/index.htm
http://www.epa.gov/nonroad-diesel/2004fr.htm
http://www.epa.gov/cleandiesel/comphelp.htm

EVENTS SINCE PROMULGATION OF THE EPA HIGHWAY ULSD FINAL RULE IN JANUARY 2001

Aug. 2001	EPA denied several petitions to reconsider the final highway ULSD rule.
May 2002	EPA convened the Clean Diesel Independent Review Panel (CDIRP) to review progress.
May 3, 2002	Appeals Court's decision upholding EPA's final highway ULSD rule
June 2002	EPA's Highway Diesel Progress Review
Oct. 2002	CDIRP issued its final report ("Meeting Technology Challenges for the 2007 Heavy-Duty Highway Diesel Rule") and disbanded.
Nov. 20-21, 2002	First ULSD fuel implementation workshop
May 23, 2003	EPA's nonroad ULSD Notice of Proposed Rulemaking published in Federal Register.
Oct. 2003	EPA's aggregate summary of the first refinery highway ULSD pre-compliance reports
March 2004	EPA's Highway Diesel Progress Review Report 2
June 29, 2004	EPA's nonroad ULSD final rule published in the Federal Register.
Sept. 2004	CDIRP issued its final report ("Meeting Technology Challenges for the 2007 Heavy-Duty Highway Diesel Rule") and disbanded.
Nov. 15-16, 2004	Second ULSD fuel implementation workshop
March 25, 2005	First ULSD fuel Q&A document
May 25, 2005	API/NPRA highway ULSD fuel survey report released.
May 27, 2005	EPA press release announcing intent of 45-day extension of effective dates for terminals and retail stations in 2006
July 15, 2005	EPA Direct Final Rule, amendments published in the Federal Register.
Sept. 2005	Revised EPA ULSD fuel Q&A document
Nov. 9-11, 2005	Third ULSD fuel implementation workshop
Nov. 22, 2005	EPA Direct Final Rule, amendments published in the Federal Register (includes additional 45 transition days in 2006, temporary 22 ppm S).
Jan. 6, 2006	EPA's amendments in the DFR (70 FR 70498; 11/22/05) effective.
April 3, 2006	EPA Direct Final Rule on gasoline and diesel test methods published in the Federal Register.
April 20, 2006	EPA released Direct Final Rule on ULSD (includes temporary 3 ppm downstream enforcement tolerance).
May 1, 2006	EPA Direct Final Rule, amendments published in the Federal Register (includes temporary 3 ppm downstream enforcement tolerance).
May 25, 2006	EPA signed a final rule for ULSD transition in Alaska.
May 31, 2006	EPA signed two enforcement discretion letters to make effective on June 1, 2006 many of the 5/1/06 amendments and the ULSD transition in Alaska. EPA signed an enforcement discretion letter on a national ULSD retail station sampling and testing program.
June 1, 2006	Federal highway ultra-low (15 ppm cap) sulfur diesel effective at refineries with a four-year temporary compliance option phase-in and with small refiner delays. Federal diesel product transfer document and pump label requirements effective to distinguish ultra-low sulfur highway diesel v. low sulfur highway diesel v. non-highway diesel fuel. Federal high sulfur NRLM diesel credits. Highway and non-road ultra-low (15 ppm cap) sulfur diesel effective in California without the federal four-year temporary compliance option phase-in and without the federal small refiner delays.
June 2, 2006	EPA amendments in DFR (71 FR 16492; 4/3/06) on gasoline, diesel test methods effective
June 15, 2006	EPA's aggregate summary of the third highway and first nonroad refinery ULSD pre-compliance reports (submitted to the Agency by June 2005) finally released.
June 30, 2006	EPA amendments in DFR (71 FR 25706; 5/1/06) effective (includes temporary 3 ppm downstream enforcement tolerance).
July 6, 2006	EPA final rule for ULSD transition in Alaska effective.
July 26, 2006	Revised EPA ULSD fuel Q&A document
Jan. 18, 2007	EPA released a question and answer document on generating high sulfur NRLM diesel credits.
June 1, 2007	Federal 500 ppm sulfur cap effective for NRLM diesel at refineries. Federal minimum cetane index of 40 or maximum aromatics content of 35 vol% effective for NRLM diesel at refineries. Federal marker (at least 6 mg/liter solvent yellow 124) requirement effective for heating oil distrbuted from a truck loading terminal except for Alaska and Northeast/Mid Atlantic areas. Federal diesel product transfer document and pump label requirement effective to distinguish ultra-low sulfur NRLM diesel v. low sulfur NRLM diesel v. high sulfur NRLM diesel v. heating oil.
Nov. 30, 2007	EPA released a memo reminding the petroleum industry of regulations on sulfur and the winter blending of kerosene with diesel.