November 16, 2010

Mr. Brian J. McLean

Director Office of Atmospheric Programs

Office of Air and Radiation U.S. Environmental Protection Agency 1200 Pennsylvania Ave., NW Washington, DC 20460

Re: Petition to Remove HFC

- 134a from the List of Acceptable Substitutes under the Significant New Alternatives Policy Program

Dear Mr. McLean:

This letter is in response to your letter of August 5, 2010, regarding NRDC’s petition to

remove HFC

- 134a from the list of acceptable substitutes for CFC

- 12 in motor vehi cle air conditioners (MVACs) and for certain other end uses. Your letter states that our petition was “incomplete” and requests information and clarification on a number of questions before responding to the petition. Here are our responses to those ques tions, responding using the headings and bullet points in your letter.

Motor Vehicle Air Conditioning :

Your letter acknowledges that the agency has identified a number of alternatives for
use in new motor vehicle air conditioners but states that EPA is “ unaware of available or potentially available alternatives for retrofits at present.” Without conceding the substance of that point, NRDC is willing to narrow the relief requested by the petition with respect to MVACs to delisting HFC

- 134a as an acceptabl e alternative in new MVACs.

Your letter asks if we have information regarding the applicability of alternatives to HFC134a in MVACs for vehicles other than light

- duty vehicles. NRDC notes that EPA recently published a fact sheet on alternative refrigeran ts for MVACs that included information on alternatives applicable to buses and trains. “Transitioning to

Low

- GWP Alternatives in MVACs,” http://www.epa.gov/ozone/downloads/EPA_HFC_MVAC.pdf

. These include the use

of R

- 744, or CO 2 , with a GWP of 1.0. Thus, we think there is a basis for delisting

HFC

- 134a as an acceptable alternative for buses, trains, and potentially additional vehicle types other than light

- duty vehicles. We do not believe , however, that thisissue should slow EPA’s response to the petition with respect to delisting HFC

- 134a

in light

- duty vehicle MACs.

Aerosols :

Your letter asks if we intended the petition to request the delisting of HFC

- 134a as an acceptable alternative in metered dose inhalers (MDIs) and for aerosol products used to clean energized electrical circuits. NRDC does not intend to pursue replacing

HFC

- 134a in MDIs at this time. However, we do intend the petition to request that

EPA declare HFC

- 134a unaccep table in products “dust

- off” type products, such as those used to blow debris off of computer keyboards and circuit boards. There is no reason not to use compressed air or other more environmentally benign substances in products of this kind. Likewise, w e request that the agency deem HFC

- 134a unacceptable in such products as silly strings, and in any other aerosol product where

safer alternatives exist.

Other End Uses :

The letter asks for further information regarding the request to delist HFC

- 134a as a n acceptable refrigerant and blowing agent in stationary refrigeration. NRDC notes two other recently published EPA fact sheets, on “Transitioning to Low

- GWP Alternatives in Domestic Refrigeration,” http://www.epa.gov/ozone/downloads/EPA_HFC_DomRef.pdf , and “Transitioning to

Low

- GWP Alternatives in Commercial Refrigeration,” http://www.epa.gov/ozone/downloads/EPA_HFC_ComRef .pdf . We think the information in those fact sheets provides a basis for delisting HFC

- 134a as an acceptable alternative for at least some applications in these sectors. As above, however, NRDC does not believe that this issue should slow EPA’s respons e to the petition with respect to delisting HFC

- 134a in light

- duty vehicle MACs.

With respect to the petition’s request that EPA consider other end uses as appropriate, we also do not believe that this issue should slow EPA’s response to the petition with respect to delisting HFC

- 134a in light

- duty vehicle MACs.

Additional Information :

Your letter asks whether we have specific information on applications where HFC

134a is used in blends. We do not have additional information to submit at this time,

and do not believe that this issue should slow EPA’s response to the petition with respect to delisting HFC

- 134a in light

- duty vehicle MACs.

These responses should provide you with the information requested to enable you to proceed without further delay on th e pending petition.

Section 612(d) of the Clean Air Act requires EPA to grant or deny a petition within 90 days of receipt. We note that the agency consumed 90 days (May 5 th to August 5 th )before sending the letter to which we are responding today. Ho wever, we also

acknowledge the time elapsed between the date of your letter (August 5 th ) and this response (November 16 th ). In view of these circumstances, we expect a substantive response to the original petition, as clarified by this letter, within 90 days of today.

Sincerely,

David D. Doniger Policy Director, Climate Center

Natural Resources Defense Council

Cc: Cindy Newberg, Chief, Alternatives and Emission Reduction Branch