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1737 King Street, Suite 390, Alexandria, VA 22314 (571) 970-3392 Fax (571) 970-3271 

www.vinylinfo.org www.vinylindesign.com

November 9, 2010

Ms. Jodi Howard

U.S. EPA - Office of Air Quality Planning and Standards 

Sector Policies and Program Divisions 

Coatings and Chemicals Group 

Mail Code: E143-01 

Research Triangle Park, NC 27711

RE: PVC MACT Rulemaking: October 26, 2010 Meeting and PVC Resin 

 Steam Stripping Comments

Dear Ms. Howard,

The Vinyl Institute (VI) and its members appreciated the opportunity to meet with you 

and your colleagues on October 26, 2010, to discuss the supplemental resin 

concentration data submitted to EPA, and to further explain resin steam stripping at 

polyvinyl chloride (PVC) manufacturing operations. I have prepared the following 

summary of our discussions, which we intend to use as a guide in responding to the 

Agency’s inquiry and request for additional information. 

1. EPA has issued a separate Section 114 Letter for resin sampling 

clarifications. As EPA stated during the meeting, a supplemental Section 114 

request letter was sent on November 1, 2010 to each PVC resin manufacturer for 

additional information regarding the locations from which resin samples were 

taken, sample handling protocols, laboratory sample compositing, laboratory 

tests used, establishment of detection limits, reporting of non-detects, actual lab 

test results, explanation of pounds per day calculations, and other details about 

the sampling process and results. Test plans for individual PVC facilities were 

submitted and approved within tight EPA-mandated time constraints. As a result, 

the Agency believes the additional information will enable it to better understand

the underlying calculated pounds-per-day submissions and supplemental resin 

concentration data, which will be used to calculate MACT floor. The Oxy Vinyls, 

LP information reviewed at this meeting appears to be a useful template for other

industry members to follow. 
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1737 King Street, Suite 390, Alexandria, VA 22314 (571) 970-3392 Fax (571) 970-3271 

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2. Time and Temperature are the controlling parameters for good steam 

stripping of PVC resin. During our meeting, you asked whether constantly 

operating the resin steam stripper under vacuum pressure conditions would 

enhance vinyl chloride monomer (VCM) removal from PVC resin. The limiting 

factor in stripping VCM from PVC resin is the time for diffusion from the interior of 

the PVC resin particle at a certain operating temperature. Resin grade and 

particle morphology are key to the size and porosity of PVC resin particles and 

their ability to be efficiently stripped of vinyl chloride. Higher operating 

temperatures, rather than lower pressures, are key to speeding the diffusion of 

vinyl chloride from the solid resin phase into the liquid phase where it is insoluble 

and quickly transferred to the gaseous phase, where the upward flowing steam 

carries it away. 

The operating pressure of stripping columns is typically maintained near 

atmospheric pressure (slightly above or below), depending on the temperature at 

which the resin must be stripped to meet a particular grade or other customer 

specification. Any further decease in pressure beyond the indicated range will 

result in a corresponding decrease in temperature, thereby reducing the rate of 

diffusion. To the extent stripper towers are operated under vacuum, it is to help 

preserve the resin particle stability and color, which is important for high product 

quality. Operating a PVC resin stripper under a vacuum will not remove greater 

amounts of vinyl chloride or associated HAPs from PVC resin. The attached 

power point slide helps to depict the various physical interactions at work in a 

resin stripper. Please let us know what more information is needed to support 

the Agency’s consideration of what is in essence a well-known and understood,

and widely practiced operating procedure within the PVC industry.

3. Use of surrogates and total HAPS. As we discussed, a close examination of 

the resin concentration data suggests that vinyl chloride could serve as an 

appropriate surrogate for VOCs. Summation of all measureable HAPs in resin 

could serve as an achievable emissions parameter. 
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1737 King Street, Suite 390, Alexandria, VA 22314 (571) 970-3392 Fax (571) 970-3271 

www.vinylinfo.org www.vinylindesign.com

4. Phase II of the PVC resin test method development program has been 

approved. Environmental Chemistry, Inc., the laboratory retained to conduct this 

study, expects to complete Phase II in approximately 6 weeks. The hybrid 8260 

B test method will be validated, and Oxy will use the method to retest some of its 

resins as a comparison to data already submitted under the Section 114 request. 

Per your request, a copy of the recently completed Phase I final report has been 

forwarded to you.

Regarding the intent to issue a separate Section 114 Request Letter to EDC/VCM 

facilities, a communication will be forthcoming to review industry’s position on this 

matter. We appreciate the opportunity to continue our dialogue with EPA. Please do 

not hesitate to contact me if you have any questions concerning the issues discussed 

during our meeting or the enclosed information, or if you require additional information. 

Sincerely, 

Richard P. Krock

Technical Director

e-mail: rkrock@vinylinfo.org

phone: 571-970-3392

cell: 571-216-4474