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 vehicle 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 questions, 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 acceptable 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 refrigerants 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 CO2, 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 this 
issue 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 unacceptable 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, we 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 an 

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 response 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 HFC134a 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 the 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 5th to August 5th) 
before sending the letter to which we are responding today. However, we also 

acknowledge the time elapsed between the date of your letter (August 5th) and this 

response (November 16th). 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