Regulatory Announcement

Direct Final Rulemaking Revising 

Mobile Source Air Toxics Early Credit 

Technology Requirement 

The U.S. Environmental Protection Agency (EPA) is issuing a direct final rulemaking to revise the February 26, 2007 mobile 

source air toxics rule’s requirements that specify the benzene control 

technologies that qualify a refiner to generate early benzene credits. 

The 2007 rule allows four benzene-reducing operational or technological changes to fulfill the early credit technological requirement. This 

action will add another specific benzene control technology, benzene 

alkylation. This action also includes a general provision that allows a 

refiner to submit a request to EPA to approve other benzene-reducing 

operational changes or technologies for the purpose of generating early 

credits. 

Background 

The Mobile Source Air Toxics rule, published on February 26, 2007, requires that 

refiners and importers produce gasoline that has an annual average benzene content 

of 0.62 volume percent (vol%) or less, beginning in 2011. The rule also requires that 

no refiner or importer have an actual average gasoline benzene level greater than 1.3 

vol%. After achieving an actual annual average benzene level of 1.3 vol%, refiners 

and importers may use benzene credits to reduce their average benzene level to 0.62 

vol%. 

Refiners may generate benzene credits for their own use or to sell to others, in two 

ways. Once the program begins in 2011, a refiner generates credits (known as standard credits) when its average annual gasoline benzene level is less than 0.62 vol%. 

(Importers can also generate standard credits.) Refiners may also generate credits prior to 2011. These credits are called early credits. In order to generate early credits, a 

refinery must meet several requirements: 

1.	 Establish a benzene baseline based on the average benzene level of the 


gasoline produced at the refinery during the two-year period 2004-05. 


Office of Transportation and Air Quality 

EPA420-F-08-007 

February 2008 
Regulatory Announcement

2.	 Make operational changes or improvements in benzene control technology that will 

result in real benzene reductions. 

3.	 Achieve an annual average benzene level at least 10% lower than its baseline level. 

In the 2007 final rule, we specified four types of operational changes and benzene control technology improvements that would allow a refinery to qualify for generating early credits if it also 

met other related requirements. These operational changes and technology improvements are: 

1.	 Treating the heavy straight run naphtha entering the reformer using light naphtha 

splitting and/or isomerization. 

2.	 Treating the reformate stream exiting the reformer using benzene extraction or benzene 

saturation. 

3.	 Directing additional refinery streams to the reformer for treatment as described in 1) and 

2) above. 

4.	 Directing reformate streams to other refineries with treatment capabilities as described in 

2) above. 

We included in this list all the strategies we thought would reduce benzene and be cost-effective. The provision was intended to not allow early credit generation solely by benzene reductions achieved through ethanol blending. The final rule did not provide a way for EPA to consider alternative means of reducing benzene, no matter how efficacious the alternative might be. 

Soon after the rule was finalized, it came to our attention that at least one refinery had plans to 

install benzene alkylation technology. Although EPA regards benzene alkylation as a legitimate 

benzene reduction technology, we did not expect it to be used. 

Today’s action revises the 2007 rule to include benzene alkylation in the list of acceptable reduction operational and technological strategies. We have also included a general provision that 

would allow a refiner to petition EPA to use an operational or technological change that is not 

listed in the regulation for the purpose of generating early credits. 

How to Comment 

This rule is being released as Direct Final Rule because we view it as a non-controversial action 

and anticipate no adverse comment. However, comments can be submitted under a parallel 

Notice of Proposed Rulemaking. Comments will be accepted for 30 days beginning when this 

proposal is published in the Federal Register. All comments should be identified by Docket ID 

No. EPA-HQ-OAR-2005-0036 and submitted by one of the following methods: 

www.regulations.gov Follow the on-line instructions for submitting comments. 

Fax: 202-566-9744. 

Mail: EPA-HQ-2005-0036 

Environmental Protection Agency 

Mailcode: 2822T 

1200 Pennsylvania Ave. NW. 

Washington, DC 20460 

Revising Mobile Source Air Toxics Early Credit Technology Requirement 
Hand Delivery:	 EPA Docket Center (EPA/DC) 


EPA Headquarters Library


Room 3334 West Building


1301 Constitution Ave., NW. 


Washington, DC 20004


Such deliveries are only accepted during the Docket’s normal 

hours of operation, and special arrangements should be made for 

deliveries of boxed information. 

For More Information 

You can access documents on this rulemaking on EPA’s Office of Transportation and Air Quality 

Web site at: www.epa.gov/otaq/toxics.htm or contact: 

Assessment and Standards Division 

U.S. Environmental Protection Agency 

Office of Transportation and Air Quality 

2000 Traverwood Drive 

Ann Arbor, MI 48105 

Voicemail: 734-214-4636 

E-mail: asdinfo@epa.gov

Regulatory Announcement

Revising Mobile Source Air Toxics Early Credit Technology Requirement