[Federal Register Volume 74, Number 179 (Thursday, September 17, 2009)]
[Proposed Rules]
[Pages 47774-47775]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-22425]



40 CFR Part 82

[EPA-HQ-OAR-2004-0488; FRL-8956-5]

Protection of the Stratospheric Ozone: Alternatives for the Motor 
Vehicle Air Conditioning Sector Under the Significant New Alternatives 
Policy (SNAP) Program

AGENCY: Environmental Protection Agency (EPA).

ACTION: Data availability.


SUMMARY: Under section 612 of the Clean Air Act, the Environmental 
Protection Agency (EPA) reviews and lists as acceptable alternatives to 
ozone-depleting substances (ODS). In 2006, EPA proposed to list R-744 
(CO2) as ``acceptable with use conditions'' as a substitute 
for CFC-12 in the motor vehicle air conditioning (MVAC) end-use within 
the refrigeration and air-conditioning sector. When using 
CO2 as a refrigerant, MVAC systems would be required to use 
the refrigerant according to those legally enforceable conditions. EPA 
proposed use conditions because of the potential risk of exposure to 
elevated concentrations of CO2 within the passenger 
compartment if there was a leak of the MVAC system. Elevated 
CO2 levels could cause passengers, and of particular 
concern, the driver, to become drowsy. Since the time of the proposed 
rule, additional information regarding the effects of short-term 
CO2 exposures has become available and EPA is now making 
that information available to the public. As noted in the proposed 
rule, EPA is considering whether to establish a breathing zone ceiling 
and this short-term exposure information is relevant to EPA's decision 
on this issue. In addition, EPA is providing the public with 
opportunity to respond to an issue raised in a public comment on the 
proposed rule.

DATES: Comments must be received on or before November 16, 2009.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2004-0488, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: [email protected].
     Fax: 202-566-1741.
     Mail: EPA Docket Center (EPA/DC), Mailcode 6102T, 
Attention Docket ID No. EPA-HQ-OAR-2004-0488, 1200 Pennsylvania Avenue, 
NW., Washington, DC 20460.
     Hand Delivery: Public Reading Room, Room 3334, EPA West 
Building, 1301 Constitution Avenue, NW., Washington, DC.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2004-0488. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, 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 http://www.regulations.gov or e-mail. The http://www.regulations.gov 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 http://www.regulations.gov 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.
    Docket: All documents in the docket are listed in the http://www.regulations.gov 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 material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Air Docket, EPA/
DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. 
This Docket Facility 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 Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Melissa Fiffer, Stratospheric 
Protection Division, Office of Atmospheric

[[Page 47775]]

Programs (6205J), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460, telephone number: (202) 343-9464, fax 
number: (202) 343-2363; e-mail address: [email protected].



1. What is today's action?
2. What information is EPA making available for review and comment?
3. Where can I get the information?
4. What is EPA taking comment on and what supporting documentation 
do I need to include in my comments?
5. What should I consider as I prepare my comments for EPA?

1. What is today's action?

    This notice of data availability (NODA) makes available to the 
public a human health effects review of R-744 (CO2) that EPA 
will consider as it moves forward to address its proposed ``acceptable 
subject to use conditions'' listing for R-744 in MVACs. In the proposed 
rule (71 FR 55140), EPA noted that a maximum CO2 
concentration never to be exceeded (``ceiling limit'') in the space 
where people breathe (``breathing zone'') may be needed in addition to 
the proposed CO2 exposure limit of 3.0% by volume averaged 
over 15 minutes. A breathing zone ceiling limit may provide additional 
assurance regarding vehicle driver alertness. EPA subsequently hired a 
contractor to examine the human health effects of elevated 
CO2 concentrations within the confined space of a vehicle 
passenger compartment. Today we are making available for comment the 
contractor-authored memo on ceiling limits for R-744 in the passenger 
compartment space of a motor vehicle. This memo reflects the latest 
information on short-term exposure to R-744 in an enclosed space.
    In 2006, EPA proposed to amend the acceptability of R-744 to 
include the use condition that MVAC systems must be designed to avoid 
occupant exposure to concentrations above the CO2 short-term 
exposure limit of 3% averaged over 15 minutes. In the proposal, EPA 
also suggested including a ceiling limit within the 3% average limit. 
Based on the analysis in the contractor-author memo made available 
today, EPA is considering a ceiling limit of 4% R-744, or 40,000 parts 
per million (ppm). This ceiling limit could not be exceeded for any 
duration inside the passenger compartment.
    In addition, during the public comment period, one commenter 
suggested that the proposed use conditions should be clarified to 
address whether the same standard applies or whether a requirement even 
applies when the motor vehicle ignition is off.

2. What information is EPA making available for review and comment?

    EPA is making available, for review and comment, a contractor-
authored memo on the toxicological impacts of short-term exposure to 
CO2 in the confined space of a vehicle passenger 
compartment, ``Review of Health Impacts from Short-Term Carbon Dioxide 
Inhalation Exposures,'' as well as the papers cited in the memo. This 
memo provides information concerning a ceiling limit for the passenger 
compartment of vehicles using R-744 in MVAC systems. In addition, the 
public comment concerning application of the proposed use conditions 
when the ignition is off is available in the public docket as item EPA-

3. Where can I get the information?

    All of the information can be obtained through the Air Docket and 
at http://www.regulations.gov (see ADDRESSES section above for docket 
contact information).

4. What is EPA taking comment on and what supporting documentation do I 
need to include in my comments?

    EPA is only accepting comment on two topics:
    1. Whether EPA should include a ceiling limit of 4% R-744, or 
40,000 ppm, in the final rule on the use of R-744 in new MVAC systems, 
in addition to the short-term exposure limit of 3% averaged over 15 
minutes, and
    2. Whether the proposed use conditions on R-744 in new MVAC systems 
should apply when the ignition is off.
    Commenters may provide any published studies or supporting 
statements. At this time, EPA is not requesting comments of a general 
or editorial nature. EPA is not accepting comments more generally on 
the proposed listing of R-744 as acceptable with use conditions. 
Interested readers are directed to 71 FR 55140 for additional 
information regarding EPA's proposed listing of R-744 as acceptable 
with use conditions in the MVAC sector.

5. What should I consider as I prepare my comments for EPA?

    You may find the following suggestions helpful for preparing your 
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide any technical information or data you used that support 
your views.
    4. Provide specific examples to illustrate your concerns.
    5. Make sure to submit your comments by the comment period deadline 
    6. To ensure proper receipt by EPA, identify the appropriate docket 
identification number in the subject line on the first page of your 
response. It would also be helpful if you provided the name, date, and 
Federal Register citation related to your comments.

List of Subjects in 40 CFR Part 82

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Reporting and recordkeeping requirements.

    Dated: August 14, 2009.
Brian J. McLean,
Director, Office of Atmospheric Programs.
[FR Doc. E9-22425 Filed 9-16-09; 8:45 am]