An equal opportunity employer 1220 L Street, Northwest Russell White Washington, DC 20005

- 4070 Health Sciences Manager Tel 202

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- 8270 whiter@api.org

August 1 , 201 2

Byron J. Bunker, Acting Division Director Compliance Division Office of Transportation and Air Quality US Environmental Protection Agency 2000 Traverwood Drive Ann Arbor, Michigan 48105

RE: Interim Report # 23

– Fuels and Fuel Additives Health Effects Testing Regulation; Pursuant to Section 211(b)(2) and 211(e) of the Clean Air Act.

Dear Mr. Bunker :
The American Petroleum Institute (API), on behalf of the Secti on 211(b) Research Group is submitting this interim report on the progress and status between 01 January 2012 and 01 July 2012 of the testing program set forth in the Alternative Tier 2 provisions of the testing regulation.

1. Toxicology Testing 1

Baseline Gasoline Vapor Condensate :

 Subchronic study (with GFAP, genotoxicity, immunotoxicity, and neurotoxicity assays)

– The final report was submitted to EPA 05 July 2007.

 Two

- generation reproductive study

– The final report was submitted to EPA 23 January 2009.

 Rat and mouse developmental toxicity studies

– The rat final report was submitted to EPA 11 August 2008. The mouse final report was revised and resubmitted to EPA 23 November 2009.

 Chronic study

– T he final report was submitted to EPA 16 June 20 10

. Gasoline/MTBE Vapor Condensate :

 Subchronic study (with GFAP, genotoxicity, immunotoxicity, and neurotoxicity assays)

– The final report was submitted to EPA 14 September 2007.

 Two

- generation reproductive study

– The final report was submitted to EPA 07 July 2011.

 Rat and mouse developmental toxicity studies

– The final report of the rat study wa s submitted to EPA 07 July 2009

. The mouse final report was submitted to EPA 04 June 2009. The final report of the repeat mouse study was submitted to EPA 06 May 2010.

 Chronic study

– The final report was submitted to EPA 16 June 2010 . A report amendm ent was submitted to EPA on 21 April 2011

.

1 All studies were conducted in rats, unless otherwise notedAugust 1 , 201 2 Page 2 of 3 Gasoline/Ethanol Vapor Condensate:

 Subchronic study (with GFAP, genotoxicity, immunotoxicity , and neurotoxicity assays)

– The final report was submitted to EPA on 24 February 2 0 10.

 One

- generation reproductive toxicity study

– The final report was submitted to EPA 29 May 2009.

 Developmental toxicity study

- The final report was submitted to EPA 10 December 2008.

Gasoline/TAME Vapor Condensate:

 Subchronic study (with GFAP, genotoxicity, immunotoxicity, and neurotoxicity assays)

– The final report was submitted to EPA on 27 December 2011.

 One

- generation reproductive study

- The final report was submitted to EPA 29 May 2009.

 Developmental toxicity study

– The final report was submitted to EPA 17 December 2008.

Gasoline/ETBE Vapor Condensate:

 Subchronic study (with GFAP, genotoxicity, immunotoxicity, and neurotoxicity assays)

– The final report was submitted to EPA on 23 March 2011

.

 One

- generation reproductive study

– The final report was submitted to EPA 06 May 2010

.

 Developmental toxicity study

– The final report was submitted to EPA 17 D e cember 2008.

Gasoline/DIPE Vapor Condensate:

 Subchronic study (with GFAP, genotoxicity, immunotoxi city, and neurotoxicity assays)

– The second draft was submitted to EPA 25 April 2012.

 One

- generation reproductive study

- The final report was submitted to EPA 02 September 2011

.

 Developmental toxicity study

– The second draft was submitted to EPA 25 April 2012

. Gasoline/TBA Vapor Condensate:

 Subchronic study (with GFAP, genotoxicity, immunotoxic ity, and neurotoxicity assays)

– The second draft was submitted to EPA 25 May 2012.

 One

- generation reproductive study

- The final report was submitted to EPA 02 September 2011

.

 Developmental toxicity stud y

- The final report was submitted to EPA 16 October 2009.

Pharmacokinetic Studies on DIPE, ETBE, and TBA :

 ETBE

– Preparation of the first draft report was in progress.

 DIPE

– T he definitive study protocol was in finalized and the in

- life studies were initiated in December 2011

.

 TBA

– Preparation of the final report for the pilot study was in progress.August 1 , 201 2 Page 3 of 3

2. Exposure Screening Studies

T he report entitled “ Section 211(B) Tier 2 High End Exposure Study of Conventional and Oxygenated Gasoline ” and previously submitted associated materials were accepted by EPA on 1 9 May 2010

. A compiled version of the final r eport was submitted to EPA on 10 June 2011, completing the Section 211(B) Tier 2 exposure screening study requir e ments.

Sincerely,

Russell White, Ph.D. Health Sciences Manager

cc: Joe Sopata, EPA (via email)