----- Forwarded by Rochelle Boyd/RTP/USEPA/US on 08/15/2012 08:39 AM -----

From: Paul Sohi <psohi@aluminum.org>

To: Rochelle Boyd/RTP/USEPA/US@EPA

Date: 08/15/2012 08:25 AM

Subject: Capture hood and work practices

Morning Rochelle,

Hope all is well, we mailed you this letter this week and wanted to email you a copy as well.

If you have any questions please feel free to contact me.

Kind regards,

Paul Sohi

Manager, EH&S

The Aluminum Association

1525 Wilson Boulevard, Suite 600,

Arlington, VA 22209

Tel: (703) 358 2976

Fax: (703) 358 2961

www.aluminum.org
Friday 10th August, 2012

Rochelle Boyd

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

109 T.W. Alexander Drive, RTP, NC 27711

Mail Drop D243-02

Dear Ms. Boyd,

The Aluminum Association is submitting these comments in response to EPA’s subpart RRR (National 

Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production) inquiry 

dated July 13th 2012. We would like to thank EPA for the opportunity to further clarify issues that will 

have direct impact on the U.S. aluminum recycling industry. After review of EPA’s questions and 

proposed language, and consultation with EPA on July 25th 2012, The Association would like to submit 

the following clarifications and suggestions.

EPA submitted two questions. The first asked for, “language that describes what constitutes 

“impractical” conditions for installing temporary hooding meeting ACGIH guidelines.”

EPA proposed the following:

“If the source is located within a building such that the hood cannot be located (because of the presence 

of a wall or roof) consistent with acceptable hood design and installation procedures the use of a 

temporary capture hood is impractical. Similarly, if the clearance required for the equipment used for 

charging, fluxing and/or drossing of the source makes it impossible to design and install a temporary 

hood in accordance with ACGIH guidelines, the use of such a hood is impractical.”

The Aluminum Association suggests replacing the above language with the following:

The installation of a temporary capture hood (with associated duct work and sampling location) is 

considered impractical in any one the following situations:

a) Building or equipment obstructions (for example, wall, ceiling, roof, structural beams, utilities, 

overhead crane, or other) are present such that the temporary hood cannot be located consistent 

with acceptable hood design and installation practices;

b) Space limitations or work area constraints exist such that the temporary hood cannot be supported 

or located to prevent inference with normal furnace operations or avoid unsafe working 

conditions for the furnace operator or source tester; 

c) The temporary hood installation or removal would require curtailment of furnace operations for 

more than eight (8) hours to ensure worker safety; 

d) The cost for design, construction, installation and removal of the temporary hood on a single 

furnace would exceed $150,000; or
2

e) The furnace is a round top configuration.

The Association has clarified on several occasions that one set of work practices during testing that could 

be applied across the industry, or to furnace categories is impossible. The variability in furnace 

installations and operating practices means that no one work practice will apply to every furnace. 

Therefore, the list of work practices to minimize emissions during testing should be linked with “or” and 

should not be linked with “and”.

EPA has proposed the following work practices to minimize fugitive emissions during testing:

2) Minimization of fugitive emissions 

Petition the permitting authority that such hoods are impractical and propose testing procedures 

that will minimize fugitive emissions. These procedures may include, but are not limited to: 

(A) Installing a hood that does not meet ACGIH guidelines, 

(B) Using the building as an enclosure, and measuring emissions exhausted from the building, 

(C) Installing temporary baffles on those sides or top of furnace opening where they will not 

interfere with material handling, 

(D) Increasing the exhaust rate from the furnace, so as to capture emissions that might otherwise 

escape into the building, 

(E) Minimizing the time the furnace doors are open, 

(F) Delaying gaseous reactive fluxing until charging doors are closed, 

(G) Delaying the addition of solid reactive flux until immediately before the charging doors are 

closed, and 

(H) Keeping building doors and other openings closed to the greatest extent possible to minimize 

drafts that would divert emissions from being drawn into the furnace. 

The Aluminum Association proposes the following changes to the proposed testing procedures:

2) Minimization of fugitive emissions

Petition the permitting authority that such hoods are impractical and propose testing procedures 
3

that will minimize fugitive emissions. These procedures may include, if practical, one or more of 

the following, but are not limited to:

(A) Installing a hood that does not meet ACGIH guidelines.

(B) Using the building as an enclosure, and measuring emissions exhausted from the building if 

there are no other furnaces or other sources operating in the building. (The Aluminum 

Association states that this option is not viable if there are other furnaces or sources inside the 

Casthouse).

(C) Installing temporary baffles on those sides or top of furnace opening if it is practical to do so 

where they will not interfere with material handling or with the furnace door opening and closing. 

(The Aluminum Association questions whether this would lower or minimize fugitive emissions).

(D) For furnaces with draft fans, increasing the exhaust rate from the furnace, so as to capture 

emissions that might otherwise escape into the building if it can be done without increasing

furnace emissions in a way that make the test non-representative. (The Aluminum Association 

states that this is not feasible for natural draft furnaces).

(E) Minimizing the time the furnace doors are open or the top is off.

(F) Delaying gaseous reactive fluxing until charging doors are closed and the top is on.

(G) Agitate or stir molten metal as soon as practicable after salt flux addition and closing doors as 

soon as possible after solid fluxing operations, including mixing and dross removal. (It is not 

feasible to add flux “immediately before closing charge doors” because solid flux must be stirred 

and dross removed through the charging door immediately after salt addition).

(H) Keeping building doors and other openings closed to the greatest extent possible to minimize 

drafts that would divert emissions from being drawn into the furnace; or

(I) Maintain burners on low-fire or pilot operation while the doors are open or the top is off.

Once again, we would like to thank you for allowing us the opportunity to comment on this issue. Please 

contact my office (703-358-2981 or CJohnson@aluminum.org) with questions or for further information.

 

 Sincerely,

 Charles D. Johnson

 VP, Environment Health & Safety