Randy:

We received comments on the FR proposal from Weston Solut ions and this comment was not in the comment (see attached). However, we have received similar commen ts from others and will consider the alternatives that were suggested in those comments. I will add your e -mail to the Docket as a late comment (the docket closed
June 26, 2009).

For your information, when we were assessing the revised test method, we used many of the traditional good la b practices for cleaning glassware and found that there we re intermittent spikes in the test results when we should have been measuring essentially blank samples. By employing the glass cleaning techniques that are used for low level organics analysis (e.g Method 23 et.al.) we wer e able to achieve consistent low blank levels. In some ways it was surprising in that it was not the organic bla nks that were the problem but the inorganic blanks. I f you look at the April 14, 2009 update of information on the development of this method you will find a draft comprehensive method development support document that w as prepared to provide detailed information on the laboratory studies and assessments that have been performed by US EPA, Environment Canada, and EPRI that provide technical support for the proposed revisions to EP A Method 202 (and OTM-28). The document, “Draft Project Report - Evaluation and Improvement of Condensa ble Particulate Measurement,” can be downloaded

from http://www.epa.gov/ttn/emc/methods/method202.html . This is much like an earlier project that I had whe re we found intermittent high results due to the inabil ity to remove all the contaminants from the glassware a nd the contaminants were released following one or two uses of the glassware.

_________________________________ Ron Myers U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Sector Policy and Programs Division Monitoring Policy Group, D243-05

RTP NC 27711

Tel. 919.541.5407

Fax 919.541.1039 E-mail myers.ron@epa.gov

Any one have thoughts or wants to handle this?

----- Forwarded by Candace Sorrell/RTP/USEPA/US on 07/08/2009 02:12 PM ----- From: Candace Sorrell/RTP/USEPA/US

To: Ron Myers/RTP/USEPA/US@EPA, Jason Dewees/RTP/USEPA/ US@EPA

Date: 07/08/2009 02:13 PM

Subject: Fw: Request for consideration re OTM-28

From: "Young, Randolph" <Randy.Young@WestonSolutions.com>

To: Candace Sorrell/RTP/USEPA/US@EPA

Date: 07/08/2009 02:11 PM

Subject: Request for consideration re OTM-28 

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...Candace—

Are you the correct person to whom we should address the se comments? Thank you.

Weston Solutions, Inc. is a significant player in the sour ce (and ambient) testing arena, and would like to ask for
your consideration of the following points in propose d OTM-28 for condensible particulate matter :

1 

### ) We would generally expect that the soap and water and two different polarity solvent rinses would effectively clean the glassware. There are a host of clean ing methods and solutions available in the literature t o clean glassware for any conceivable purpose. Is there som e technical basis for the 300C baking temperature, such as volatilizing vacuum greases or other common contamin ants? Or was this simply what was used during method development? Has the 300 deg C step been shown in field work to be necessary? 2) In general, the method is quite proscriptive instead of being performance based. Are there blank considerations as cut-off levels, for instance (the 2 mg speci fied?), that might allow for streamlining certain ste ps?
Most notably, the high-temperature baking? 

### 3) What is the temperature tolerance on the 300 deg C?



### Thanks in advance for your consideration of these items. We look forward to your response.

Randy Young

Weston Solutions

Phone: 513-492-7324

Cell: 513-382-7549

FAX: 937-531-4401



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