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September 19, 2013



Ms. Susan Fairchild
Sector Policies and Programs Division
Metals and Minerals Group (D243-02)
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
4930 Old Page Road
Durham, NC  27703

      RE:	EPA's Draft Work Practice Standards For HF and HCl Emissions From Wool Fiberglass Melting Furnaces

Dear Ms. Fairchild:

NAIMA greatly appreciates the opportunity to provide comments on the attached "Draft Work Practice Standards for HF and HCl Emissions from Wool Fiberglass Melting Furnaces."  The attached document and accompanying redlined document convey NAIMA's comments.  Throughout the document, NAIMA has eliminated the use of the word "e-glass," which in EPA's draft seems to have referenced glass from electronics.  "E-glass" is an industry term of art used to describe a specific glass type in the continuous filament fiber glass industry which was originally developed for military uses, but e-glass is not the type of glass used at facilities subject to NNN in the production of wool fiber glass.

Please note that there are some instances where a small amount of fluoride is included in the glass formulation used to produce wool fiber glass.  Test results on melters using fluoride in the glass chemistry at locations subject to NNN were similar for HF to results for other HF tests in the ICR process, and in no event exceeded a 0.25 ton per year emission rate.

In addition, the rolling average referenced in the revised work practice needs to be a flexible average simply because the companies do not test monthly.  The average referenced in the work practice will likely be based in multiple tests, but not monthly tests.

Please contact me if you have any questions.

Sincerely,

Angus E. Crane
Executive Vice President, General Counsel

Attachments
cc:	Mr. Keith W. Barnett
	Group Leader, Office of Air Quality and Planning Standards
	Sector Policies and Programs Division, Mineral and Manufacturing Group
      U.S. Environmental Protection Agency
      4930 Old Page Road
      Durham, NC  27703
