Occidental Chemical Corporation 

 Corporate Office 

5005 LBJ Freeway, Dallas, TX 75244-6119 

 P.O. Box 809050, Dallas, TX 75380-9050 

 972/404-3800 

September 24, 2010 

Via Electronic Mail 

Jodi Howard 

Environmental Engineer 

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 

Howard.Jodi@epamail.epa.gov 

Re: PVC MACT Rulemaking—Clarification of PVC Resin Concentration 

Data Supplementing Submissions in Response to EPA’s Section 114 

Request 

Dear Ms. Howard: 

This letter is intended to clarify that the resin concentration data generated by Oxy 

Vinyls, LP (“OxyVinyls”) pursuant to the above-referenced rulemaking was incorporated 

into the concentration data spreadsheet submitted to the Agency by the Vinyl Institute 

(“VI”) on September 16, 2010. The data in the spreadsheet constitutes analytical 

results of polyvinyl chloride (“PVC”) resin samples collected in response to the Agency’s 

August 21, 2009, and September 21, 2009, information collection requests under the 

authority of Section 114 of the Clean Air Act (hereinafter “114 Request”). This PVC 

resin sampling and analysis program was approved by the Agency on November 02, 

2009, for our Pasadena, TX and Pedricktown, NJ facilities and November 19 and 23, 

2009, for our Deer Park, TX facility. This data identified and quantified hazardous air 

pollutants that may be emitted from PVC resin processing at each of the three 

OxyVinyls PVC facilities. As described in our three EPA-approved sampling plans 

(Deer Park, TX Resin Sampling and Analysis Plan, Pasadena, TX Resin Sampling Plan, 

and Pedricktown, NJ Resin Sampling and Misc. Fugitive Source Plan), the resin 

analytical results (or concentrations) were used to calculate estimated quantitative mass 

emissions for HAPs. The results were reported on the EPA 30-Day Resin Sampling 

Spreadsheets for Stripper and Dryer Outlets, which were initially submitted on March 1, 

2010, followed by a revised set of Resin Sampling Spreadsheets on April 21, 2010, 

which, at that time, also included a CBI submission of separate daily spreadsheets 
Occidental Chemical Corporation 

 Corporate Office 

5005 LBJ Freeway, Dallas, TX 75244-6119 

 P.O. Box 809050, Dallas, TX 75380-9050 

 972/404-3800 

showing analytical results for HAPs concentrations, and HAP loadings calculated from 

those concentrations. 

Upon reviewing the 114 Request data published on the Agency’s website, it 

quickly became apparent that inconsistent methods had been used to convert the resin 

concentration results into estimated mass emissions. For example, we understand that 

some facilities used production volume from the entire plant to calculate the quantitative 

mass emissions, while OxyVinyls used only the volume from the production lines being 

sampled. Each of our three PVC plants estimates production volume differently. Rather 

than evaluating the accuracy of each plant’s method of determination of daily production 

and the impact of this on mass emission estimates, use of laboratory concentration data 

seems like the more consistent approach. As VI indicated in its September 16, 2010 

submission, there were other inconsistencies in the emission calculations stemming 

from the varying nature of sampling and testing plans approved by the Agency and 

assumptions made by each company in performing mass balance calculations. 

Data provided by OxyVinyls in March and April of 2010 previously provided resin 

concentration data for each day of our 30 day sampling program, as well as an example 

to illustrate our mass calculation methodology. The only change from the HAP 

concentration data in the previously submitted daily spreadsheets that are now reflected 

in the VI concentration database is described below: 

Upon review of several laboratory reports, it was determined that many of the reported 

non-detectable concentrations in our previous submissions were actually lab Reporting 

Levels (RLs), not non-detection (ND) levels, which were incorrectly flagged with ‘U’* 

qualifiers. This occurred because the laboratory had not completed an MDL study for 

the selected ion monitoring (SIM) mode of operation of the mass spectrometer, used to 

enhance detection limits in Method 8260, until late in the project. Thus, the newly 

determined MDLs did not appear on the lab reports, and the RLs that were on the lab 

reports were inadvertently reported as ‘U’ flagged detection limits in the daily 

concentration spreadsheets previously to the Agency. This error was first detected only 

a few weeks ago, so OxyVinyls made the appropriate changes in the newly compiled 

Vinyl Institute concentration spreadsheet, but has not yet made those changes in the 

daily spreadsheets previously submitted in April 2010. The changes that were made to 

the Vinyl Institute spreadsheet were only to replace incorrect U flags with RL flags so 

that the data user knows that the number in the adjacent column is a reporting limit, not 

a detection limit. OxyVinyls is in the process of obtaining correct MDL values for each 

sample and each HAP analyte from the laboratory via revised lab report pages, so that 

the Vinyl Institute spreadsheet can be updated with correct numerical values for 

* U - Not present at or above the associated value 
Occidental Chemical Corporation 

 Corporate Office 

5005 LBJ Freeway, Dallas, TX 75244-6119 

 P.O. Box 809050, Dallas, TX 75380-9050 

 972/404-3800 

detection limits, at which time the RL flags will be changed to correct U flags. The 

impact of these changes on our reported mass values is not expected to be significant. 

However, since we do not know how EPA has used the OxyVinyls data set, we can not 

be certain of the potential significance. 

Accordingly, OxyVinyls believes that the resin data submitted by VI, which is the 

actual measured concentration data before the application of any mass calculations, 

presents the best available set of data generated from our study, and is the best set of 

data from which to develop a maximum achievable control technology standard for the 

PVC and Copolymer production category. 

In closing, OxyVinyls wishes again to emphasize that the spreadsheet 

submission does not amend any data previously submitted to the Agency in response to 

its 114 Request. Rather it is the measured data that formed the basis of the emissions 

estimates provided in the EPA 30-Day Resin Sampling spreadsheets. The OxyVinyls 

resin sampling data was developed in accordance with the approach set out in its EPAapproved sampling plan and it was not until VI members examined this data collectively 

that the inconsistencies in reporting became apparent. 

Please do not hesitate to contact me at 972-404-3209 if you have any questions 

or concerns. 

 

 Respectfully, 

 

 Barry Christensen 

 Occidental Chemical Corp. 

 Manager Air Quality