Diesel exhaust contains pollutants that may increase asthma, respiratory problems, and cancer. Bits of soot, called particulate matter, and gases threaten our health when we breathe diesel exhaust. Other pollutants such as nitrogen oxide gas and sulfur oxides contribute to acid rain and irritate the lungs. Nitrogen oxide gas also contributes to ozone formation.

The U.S. Environmental Protection Agency (EPA) passed new rules requiring very low levels of sulfur in diesel fuel for use in trucks, buses, construction equipment, and other mobile sources. EPA recently proposed similar rules for stationary sources like power generators. Fuel sulfur levels will be reduced in fall 2006 for diesel used in on-highway mobile sources like trucks and buses. Fuel sulfur levels will drop in 2007, and again in 2010, for “nonroad” mobile sources like construction equipment. This new diesel is called ultra low sulfur diesel.

Ultra low sulfur diesel allows new sulfur sensitive emission control equipment to reduce particulate matter and nitrogen oxide gas by over 90%. The new equipment is disabled by high levels of sulfur in the exhaust gas, which is controlled by using ultra low sulfur diesel. For now, these rules only apply to mobile sources. Proposed rules are in the works for power generation. Federal rules do not yet apply to home heating fuels.

Older vehicles and equipment will run on ultra low sulfur diesel. Older vehicles and equipment using ultra low sulfur fuel will also experience a small reduction in particulate matter. However, vehicles and equipment outfitted with new emission control technology can fail if run on the higher sulfur diesel fuel currently in use.

Click on the links below to find out more on how DEC is dealing with federal fuel rules and their impacts on Alaskans.

Alaska’s Diesel Strategy - Background

1. Rule Flexibility

2. North Slope Oil Producer Agreement

3. Alaska Retrofit Projects

4. Diesel Exhaust Health Assessment

5. Economic Analysis

Fuel for Thought - ULSD Questions and Answers

Recent Announcements

• EPA released the Alaska-specific rule to implement the federal ultra low sulfur diesel rules in Alaska. For specifics, click here: http://www.epa.gov/otaq/regs/fuels/diesel/diesel.htm

• See EPA's fact sheet on the Federal Ultra-Low Sulfur Diesel Fuel Requirements.

• If you have questions on the implementation of EPA's 2007 Highway Diesel Rule and the Nonroad Diesel Rule, go to EPA's compliance assistance page at http://www.epa.gov/cleandiesel/comphelp.htm.

Contact Clint Farr at 907-465-5127, or email: Clint.Farr@alaska.gov if you have questions regarding ultra low sulfur diesel and DEC's role.