From: Chuck French [French.Chuck@epamail.epa.gov]

Sent: Tuesday, August 14, 2012 11:41 AM

To: Higgins, Cortney

Cc: Ann Johnson; Hancy, Cindy Wang; Erin Newman; Fred Talcott; Jan Tierney; Kelly Rimer;

Mark Morris; Phil Mulrine; Marinshaw, Richard; Robin Langdon; Sara Ayres; Steve Fruh;

Tim Benner; Tom Walton

Subject: RE: EO 13563 Interagency Comments on Chromium RTR

Categories: Red Category

Hi Cortney,

Regarding the question (shown below) on the Danish study, here is a summary of the

calculati ons we did to equate the Danish Study data to US equivalent:

Flow rate during Danish tests: 180 dscm/hr = 106 dscf/min

Tank surface area: 0.22 m2 = 2.37 ft2

Actual ventilation rate in Danish study: 106/2.37 = 44.7 CFM/m2

Recommended minimum venti lation rate in US: 250 CFM/m2

Adjusted flowrate for Danish Study: 250 x 2.37 = 592 CFM

Estimated at standard conditions: 592 x 0.96 = 568 dscf/min

Factor to convert Danish study results to US equivalent: 106/568 = 0.187

Average concentrations rep orted in Danish study:

Using PFOS: 0.117 mg/dscm

Using Non

- PFOS: 0.0362 mg/dscm

Adjusted concentrations

Using PFOS: 0.117 x 0.187 = 0.022 mg/dscm

Using Non

- PFOS: 0.0362 x 0.187 = 0.0067 mg/dscm

The recommended ventilation rate of 250 CFM/ft2 in the U.S. is what is required “to

maintain minimum control velocities” across the tank surface area. Thus, tanks are

typically designed for higher ventilation rates, thereby decreasing emissions

concent ration. Therefore, the calculated value of 0.0067 mg/dscm is considered a

maximum value and actual tanks would have greater flow rate and lower emissions

concentrations.

Reference for recommended ventilation rate: Industrial Ventilation

– A Manual of

Recommended Practice, American Conference of Governmental Industrial Hygienists.

Let us know if you have questions.

Thanks.

Chuck

Phone: 919

- 541

- 7912

"Higgins, Cortney"

--- 08/14/2012 09:00:12 AM

--- Hi Chuck, I received the following qu estion

- can we

talk about this at noon today? I'll let you knFrom: "Higgins, Cortney" <Cortney_Higgins@omb.eop.gov>

To: Chuck French/RTP/USEPA/US@EPA

Date: 08/14/2012 09:00 AM

Subject: RE: EO 13563 Interagency Comments on Chromium RTR

Hi Chuck,

I received the following question

– can we talk about this at noon today? I’ll let you know by noon if

there are any

additional questions.

It would be useful to get a quick explanation of how EPA compared the Danish surface tension

levels t o what they would be in the USA due to EPA’s reliance on increased air flow (or add on

control devices used) in the USA. The Danish study does mention that fume suppressants work

better with less air flow.

Thanks,

Cortney

From: Chuck French [ mailto:French.Chuck@epamail.epa.gov]

Sent: Monday, August 13, 2012 12:36 PM

To: Higgins, Cortney

Subject: Re: EO 13563 Interagency Comments on Chromium RTR

Hi Cortney,

I realize you are out of the office today. I hope you are having a good day. Anyw ay, please let us know

ASAP if there are any remaining comments or issues.

Thanks.

Chuck

Phone: 919

- 541

- 7912

"Higgins, Cortney"

--- 08/10/2012 09:46:29 PM

--- Yes. Thanks! From: Chuck French

[mailto:French.Chuck@epamail.epa.gov]

From: "Higgins, Cortney" <Cortney_Higgins@omb.eop.gov>

To: Chuck French/RTP/USEPA/US@EPA

Date: 08/10/2012 09:46 PM

Subject: Re: EO 13563 Interagency Comments on Chromium RTR

Yes. Thanks!From: Chuck French [mailto:French.Chuck@epamail.epa.g ov]

Sent: Friday, August 10, 2012 06:31 PM

To: Higgins, Cortney

Subject: Fw: EO 13563 Interagency Comments on Chromium RTR

Hi Cortney,

Did you receive the revised preamble/rule?

Thanks.

Have a good weekend.

Chuck

Phone: 919

- 541

- 7912

----- Forwarded by Chuck French/RTP/USEPA/US on 08/10/2012 06:29 PM

-----

From: Chuck French/RTP/USEPA/US

To: Chuck French/RTP/USEPA/US@EPA

Cc: "Higgins, Cortney" <Cortney_Higgins@omb.eop.gov>, Ann Johnson/DC/USEPA/US@EPA,

Mark Morris/RTP/USEPA/US@E PA, Nathan_J._Frey@omb.eop.gov, Phil

Mulrine/RTP/USEPA/US@EPA, Robin Langdon/RTP/USEPA/US@EPA, Tom

Walton/RTP/USEPA/US@EPA, chancy@rti.org, Erin Newman/R5/USEPA/US@EPA, Jan

Tierney/DC/USEPA/US@EPA, Kelly Rimer/RTP/USEPA/US@EPA, rjmarinshaw@rti.org,

Sara Ayres/DC/USEPA/US@EPA, Steve Fruh/RTP/USEPA/US@EPA, Tim

Benner/DC/USEPA/US@EPA

Date: 08/10/2012 06:24 PM

Subject: Re: EO 13563 Interagency Comments on Chromium RTR

Hi Cortney,

We made edits to the preamble/rule to address comments we discus sed on 8/8/2012. Attached is a

revised preamble and rule. One version shows changes in "track changes", the other is a clean version.

Let me know if you have questions.

Thanks.

Chuck French

Phone: 919

- 541

- 7912

[attachment "E O 12866 CromiumElectroplatingSteelPickling 2060

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- 2012

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epa

- edits.docx" deleted by Chuck French/RTP/USEPA/US] [attachment "E O 12866

CromiumElectroplatingSteelPickling 2060

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by Chuck French/RTP/USEPA/US]