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Technical Memorandum

Date: March 30, 2011

Subject: Summary of U.S. EPA Discussions with Zeon Chemicals L.P. Representatives to 

Discuss the Polymers and Resins I Portion of the 2010 RTR Proposal/Supplemental Proposal

From: Nick Parsons, EPA/OAR/OAQPS/SPPD/RCG

The purpose of this memorandum is to summarize a series of discussions between 

representatives of the U.S. Environmental Protection Agency (EPA) and Zeon Chemicals L.P. 

The topic of these discussions was the proposed revisions to the National Emission Standards for 

Hazard Air Pollutants (NESHAP) for Polymers and Resins I (40 CFR part 63, subpart U), 

specifically for the Epichlorohydrin and Nitrile Butadiene Rubber Production source categories.

Participants

Nick Parsons, U.S. EPA

Tom Herman, Zeon Chemicals

Bill Simpson, Zeon Chemicals

Dates of Discussions

January 21, 2011

January 28, 2011

January 31, 2011

March 4, 2011

Summary of Discussions

The purpose of these meetings was to discuss Zeon Chemicals’ comments on the October 

21, 2010 proposal/supplemental proposal for several source categories, including the 

Epichlorohydrin Elastomer and Nitrile Butadiene Rubber (NBR) Production source categories of 

the Polymers and Resins I MACT (75 FR 65068).

Zeon Chemicals representatives presented their concerns with the proposed requirements 

for the Epichlorohydrin and Nitrile Butadiene Rubber production source categories. The key 

issue of concern for the company was that the proposed back-end emission limits for the source 

categories did not take into account process variability (i.e., different product mixes) that would

lead to varying levels of organic HAP emissions per amount of elastomer produced.

Based on these discussions, Zeon Chemicals submitted additional process and production 

information to be considered in setting the back-end emission limit, including several years of
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historical emissions for their NBR plant. While this type of information showing emissions

variability due to varied product mix was not available for their Epichlorohydrin Elastomer plant,

Zeon Chemicals representatives provided the following rationale for why it was appropriate to

incorporate the variability from the NBR plant in setting the MACT floor limit for the

Epichlorohydrin Elastomers source category:

The processes which contribute to the majority of the back-end emissions are very 

comparable between the KY Plant NBR and MS Plant ECO (Epi) manufacturing 

operations. The two ECO drying processes at the MS Plant are apron-type dryers, where 

heated air is passed over and through the wet crumb rubber as it passes down through an 

oven-like chamber on a moving perforated stainless steel apron conveyor. The two main 

NBR drying processes at the KY Plant are also apron dryers. As product mix varies, so 

can residual monomer and/or residual solvent vary and, as a result, so can HAP 

emissions vary. Recent product mix variability has not been as great at the MS Plant as it 

has at the KY Plant. Nevertheless, the potential for variability is there at the MS Plant. 

To offset this lack of recent data to represent the MS Plant and its ECO manufacturing 

variability, we propose to use the same variability factor for ECO manufacturing as has 

been developed for NBR manufacturing.

EPA agreed with Zeon Chemicals rationale that the back-end processes from the NBR

plant are similar to the Epicholorhydrin plant, and incorporated the same emissions variability

factor in setting the MACT floor for both the NBR and Epichlorohydrin source categories.
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Appendix

Supplemental Emissions Information
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Zeon Chemicals L.P.

Kentucky Plant

MACT Polymers & Resins I (Subpart U) Back-End Emissions

Nitrile Butadiene Rubber Production

114 Questionnaire Supplemental Information

Year Back-End 

1,3-Butadiene

Emissions (TPY)

Back-End 

Acrylonitrile 

Emissions (TPY)

Nitrile Rubber 

Production (TPY)

Nitrile Latex

(dry basis)

Production (TPY)

2005 3.489 12.18 Confidential Confidential

2006 2.625 11.92 “ “

2007 2.796 11.50 “ “

2008 0.547 4.046 “ “

2009 0.308 1.454 “ “

The above emissions were totaled from the following Emission Release Point ID’s, ordered by 

appearance on the 114 Questionnaire response spreadsheet:

BT3134 BT3537 DRYNCW PBL2 PBL3 PBL5

SD1BLT SD2BLT SDR1SD T45678 BT3839 PBL1

PBL6 SDNDR2 SDR2SD SD2RTO BT1920 BT2126