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Review of the National Ambient Air Quality Standards for Carbon Monoxide

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Information about this document as published in the Federal Register.

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Environmental Protection Agency (EPA).


Notice of draft document for public review and comment.


On or about April 15, 2009, the Office of Air Quality Planning and Standards (OAQPS) of EPA is making available for public review and comment a planning document titled Carbon Monoxide National Ambient Air Quality Standards: Scope and Methods Plan for Health Risk and Exposure Assessment. This document describes EPA's planned approach for developing analyses as part of the review of the National Ambient Air Quality Standards (NAAQS) for carbon monoxide (CO). The EPA is releasing this planning document to seek consultation with the Clean Air Scientific Advisory Committee (CASAC) and to solicit public comments.


Comments should be submitted on or before June 15, 2009.


Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2008-0015, by one of the following methods:

  • Follow the on-line instructions for submitting comments.
  • E-mail:
  • Fax: 202-566-9744.
  • Mail: EPA-HQ-OAR-2008-0015, Environmental Protection Agency, Mail code 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 20460. Please include a total of two copies.
  • Hand Delivery: Environmental Protection Agency, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-2008-0015. The EPA's policy is that all comments received will be included in the public docket without change and may be made available online at, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through (or e-mail). The Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket, visit the EPA Docket Center homepage at​epahome/​dockets.htm.

Docket: All documents in the docket are listed in the index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other materials, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically in or in hard copy at the Air and Radiation Docket and Information Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Air and Radiation Docket and Information Center is (202) 566-1742.

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Any questions concerning EPA's Carbon Monoxide National Ambient Air Quality Standards: Scope and Methods Plan for Health Risk and Exposure Assessment should be directed to Ms. Ines Pagan at, telephone 919-541-5469.

General Information

A. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI

Do not submit this information to EPA through or e-mail. Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a disk or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM as CBI and then identify electronically within the disk or CD ROM, the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

2. Tips for Preparing Your Comments

When submitting comments, remember to:

  • Identify the rulemaking by docket number and other identifying information (subject heading, Federal Register date and page number).
  • Follow directions—The Agency may ask you to respond to specific questions or organize comments by referencing a Code of Federal Regulations (CFR) part or section number.
  • Explain why you agree or disagree; suggest alternatives and substitute language for your requested changes.
  • Describe any assumptions and provide any technical information and/or data that you used.
  • If you estimate potential costs or burdens, explain how you arrived at your estimate in sufficient detail to allow for it to be reproduced.
  • Provide specific examples to illustrate your concerns, and suggest alternatives.
  • Explain your views as clearly as possible, avoiding the use of profanity or personal threats.
  • Make sure to submit your comments by the comment period deadline identified.
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Under section 108(a) of the Clean Air Act (CAA), the Administrator identifies and lists certain pollutants which “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.” The EPA then issues air quality criteria for listed pollutants, which are commonly referred to as “criteria pollutants.” The air quality criteria are to “accurately Start Printed Page 17491reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of [a] pollutant in the ambient air, in varying quantities.” Under section 109 of the CAA, EPA establishes NAAQS for each listed pollutant, with the NAAQS based on the air quality criteria. Section 109(d) of the CAA requires periodic review and, if appropriate, revision of existing air quality criteria. The revised air quality criteria reflect advances in scientific knowledge on the effects of the pollutant on public health or welfare. The EPA is also required to periodically review and revise the NAAQS, if appropriate, based on the revised criteria.

Air quality criteria have been established for CO to provide protection from exposure to ambient concentrations of CO. Presently, EPA is reviewing the air quality criteria and NAAQS for CO. The EPA's overall plan and schedule for this review is presented in the Integrated Review Plan for the National Ambient Air Quality Standards for Carbon Monoxide.[1] A draft of the integrated review plan was released for public review and comment in March 2008 and was the subject of a publicly accessible teleconference consultation with the CASAC on April 8, 2008 (73 FR 12998). Comments received from that consultation and from the public were considered in finalizing the plan and in beginning the review of the air quality criteria.

As part of the review of the air quality criteria for CO, EPA's Office of Research and Development (ORD) has completed a draft document, Integrated Science Assessment (ISA) for Carbon Monoxide (First External Review Draft, March, 2009) and requested review by the CASAC and the public (74 FR 10734; March 12, 2009). In the future, EPA's OAQPS will prepare a Risk and Exposure Assessment (REA) focusing on human exposure, and possibly, risk assessment. The planning document announced today describes the planned approaches for conducting the quantitative assessments that will be presented in the REA as part of the review of the primary (health-based) standards. This planning document is available on the Agency's Technology Transfer Network (TTN) Web site at​ttn/​naaqs/​standards/​co/​s_​co_​cr_​pd.html. This document may be accessed in the “Documents from Current Review” section under “Planning Documents.” This planning document is intended to provide enough specificity to facilitate consultation with CASAC, as well as for public review, in order to obtain advice on the overall scope, approaches and key issues in advance of conducting quantitative analyses and presentation of results in the first draft REA. The CASAC consultation on this planning document coincides with its review of the first draft ISA. This CASAC meeting is scheduled for May 12 and 13, 2009. A separate Federal Register notice (74 FR 15265; April 3, 2009) provides additional details about this meeting and the process for participation.

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Dated: April 7, 2009.

Jennifer N. Edmonds,

Acting Director, Office of Air Quality Planning and Standards.

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[FR Doc. E9-8671 Filed 4-14-09; 8:45 am]