1747 Pennsylvania Av, Suite 825 Washington, DC 20006.●(571) 970-3359● Fax (571) 970-3271

www.vinylinfo.org ●www.vinylindesign.com

October 26, 2014

Sent via Electronic Mail and FedEx 

Ms. Jodi Howard

Environmental Engineer, Refining and Chemicals Group

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

109 T.W. Alexander Drive 

Mail Code: E143-01

Research Triangle Park, NC 27711

Howard.Jodi@epa.gov

RE: Polyvinyl Chloride and Copolymers Resins – Definitions and Process 

Information

Dear Ms. Howard:

Following-up on the September 22, 2014, discussions between the Vinyl Institute (“VI”) 

and the Environmental Protection Agency (“EPA”), the VI PVC MACT Copolymer 

Subgroup1 has developed proposed changes and clarifications to the definitions of the 

resin types and processes in the National Emission Standards for Hazardous Air 

Pollutants for Polyvinyl Chloride and Copolymers Production (“PVC MACT”).

2

As the Agency is aware, Lubrizol Corporation and Wacker Chemical Corporation will be 

regulated under the PVC MACT as manufacturers of PVC copolymer resins.3 The 

proposed changes and additional definitions, which are enclosed as Attachment A,

identify and clarify PVC and copolymer resin types and processes for subcategorization 

purposes.4 Particularly, these recommendations address undried copolymer resins

manufactured by these facilities. Additional information on resin process types is 

included as Attachment B for the Agency’s reference.

The Vinyl Institute and the VI PVC MACT Copolymers Subgroup appreciate EPA’s 

consideration of this important matter. Please do not hesitate to contact me with any 

questions. 

 

1 The VI PVC MACT Copolymer Subgroup includes VI members Formosa Plastics Corporation, U.S.A., Wacker Chemical 

Corporation, and Lubrizol Corporation.

2 77 Fed. Reg. 22,848 (April 17, 2012). 

3 Both Lubrizol and Wacker timely filed the required notification of applicability of the PVC MACT final rule within 120 days of its 

effective date. In addition, these companies have filed quarterly reports for their operations under the Vinyl Chloride NESHAP. 

4 Both Wacker and the VI previously filed comments concerning copolymers for the proposed PVC MACT rule.
VI PVC MACT Copolymers Subgroup Proposed Definitions, October 26, 2014

Page 2 of 5

The Vinyl Institute, 1747 Pennsylvania Av, Suite 825 Washington, DC 20006.(571) 970-3392 Fax (571) 970-3271 

www.vinylinfo.org www.vinylindesign.com

Sincerely, 

Richard P. Krock

Technical Director

e-mail: rkrock@vinylinfo.org

phone: (202) 765-2287

cell: 571-216-4474

CC: Ms. Penny Lassiter, EPA-RTP

Mr. Andrew Bouchard, EPA-RTP

Mr. Mark Kataoka, EPA-OCG

JC Walker, Keller and Heckman

Vinyl Institute PVC MACT Copolymers Subgroup

Vinyl Institute PVC MACT Working Group

Enclosures:

Attachment A: Definitions and Proposed Changes for Resin Process Types in the PVC 

MACT

Attachment B: Resin Process Types Information

4813-1074-4352, v. 1
VI PVC MACT Copolymers Subgroup Proposed Definitions, October 26, 2014

Page 3 of 5

The Vinyl Institute, 1747 Pennsylvania Av, Suite 825 Washington, DC 20006.(571) 970-3392 Fax (571) 970-3271 

www.vinylinfo.org www.vinylindesign.com

Attachment A – Definitions and Proposed Changes for Resin 

Process Types in the PVC MACT 

October 26, 2014 Draft for Discussion with Jodi Howard, EPA

Definitions in the VCM NESHAP (40 C.F.R. § 61.61):

Note: There is no definition of “suspension resin” in the VCM NESHAP.

(c) Polyvinyl chloride (PVC) plant includes any plant where vinyl chloride alone or in combination with 

other materials is polymerized.

(e) Type of resin means the broad classification of resin referring to the basic manufacturing process for 

producing that resin, including, but not limited to, the suspension, dispersion, latex, bulk, and solution 

processes.

(f) Grade of resin means the subdivision of resin classification which describes it as a unique resin, i.e., 

the most exact description of a resin with no further subdivision.

(g) Dispersion resin means a resin manufactured in such a way as to form fluid dispersions when 

dispersed in a plasticizer or plasticizer/diluent mixtures.

(h) Latex resin means a resin which is produced by a polymerization process which initiates from free 

radical catalyst sites and is sold undried.

Definitions in the PVC MACT (40 C.F.R. § 63.12005):

Note: Additions to the definitions of “dispersion process, “polyvinyl chloride homopolymer”, and “polyvinyl 

chloride copolymer” are underlined and deletions are in strikethrough. A new term, “latex process” is 

added.

Dispersion process means a process for producing polyvinyl chloride resin using either the emulsion or 

microsuspension process. These polymerization techniques produce fine particles (1-10 microns) with 

little or no porosity. Emulsifier levels vary but agitation is very mild compared to other PVC polymerization 

processes. The final product is either a dispersion resin or an emulsion resin and both are dried to 

powder form. The emulsion resins are smaller in particle size. that is characterized by the formation of 

the polymers in soap micelles that contain small amounts of vinyl chloride monomer. Emulsifiers are used 

to disperse vinyl chloride monomer in the water phase. Initiators used in the dispersion process are 

soluble in water. Resins produced using the dispersion process are referred to as latex or dispersion 

resins.

Grade means the subdivision of PVC resin that describes it as a unique resin, i.e., the most exact 

description of a type of resin with no further subdivision. Examples include low molecular weight 

suspension resins and general purpose suspension resins. 

Latex process means a process for producing polyvinyl chloride resin that is characterized by metered 

addition of monomer and other ingredients as the reaction progresses, typically in a modified semi-batch 

or semi-continuous emulsion polymerization process. This modified emulsion process creates very fine 

particles that have a typical average particle size of less than 0.5 microns. Latex is stripped using steam, 

oxidation-reduction, or other method to eliminate residual monomers yet preserve the sensitive latex 

product form. Polyvinyl chloride resin produced using the latex process is sold in an undried form.
VI PVC MACT Copolymers Subgroup Proposed Definitions, October 26, 2014

Page 4 of 5

The Vinyl Institute, 1747 Pennsylvania Av, Suite 825 Washington, DC 20006.(571) 970-3392 Fax (571) 970-3271 

www.vinylinfo.org www.vinylindesign.com

Polyvinyl chloride means either polyvinyl chloride homopolymer or polyvinyl chloride copolymer. 

Polyvinyl chloride homopolymer means a synthetic thermoplastic polymer that is derived from the 

polymerization of vinyl chloride and has the general chemical structure (-H2CCHCl-)n. Polyvinyl chloride 

homopolymer is typically a white powder or colorless granule. Polyvinyl chloride homopolymer is 

produced by different processes, including (but not limited to), suspension, dispersion or /emulsion, 

blending, latex, and bulk processes. 

Polyvinyl chloride copolymer means a synthetic thermoplastic polymer that is derived from the 

simultaneous polymerization of vinyl chloride and another monomer such as vinyl acetate. Polyvinyl 

chloride copolymer is produced by different processes, including, but not limited to, suspension, 

dispersion or /emulsion, suspension blending, latex, and solution processes.

Product means a polymer produced using the same monomers and varying in additives (e.g., initiators, 

terminators, etc.); catalysts; or in the relative proportions of monomers, that is manufactured by a process 

unit. With respect to polymers, more than one recipe may be used to produce the same product, and 

there can be more than one grade of a product. Product also means a chemical that is not a polymer, 

which is manufactured by a process unit. By-products, isolated intermediates, impurities, wastes and 

trace contaminants are not considered products.

Suspension process means a process for producing polyvinyl chloride resin that is characterized by the 

formation of the polymers in droplets of liquid vinyl chloride monomer or other co-monomers suspended 

in water. The droplets are formed by agitation and the use of protective colloids or suspending agents. 

Initiators used in the suspension process are soluble in vinyl chloride monomer. Polyvinyl chloride resins 

produced using the suspension process are referred to as suspension resins. 

Suspension blending process means a process for producing polyvinyl chloride resin that is similar to 

the suspension polymerization process, but employs a rate of agitation that is significantly higher than the 

highest range for non-blending suspension resins. The suspension blending process uses a recipe that 

creates extremely small resin particles, generally equal to or less than 100 microns in size, with a glassy 

surface and very little porosity. The suspension blending process concentrates the resins using a 

centrifuge that is specifically designed to handle these small particles. Polyvinyl chloride resins produced 

using the suspension blending process are referred to as suspension blending resins and are typically 

blended with dispersion resins. 

4841-1267-0496, v. 1
VI PVC MACT Copolymers Subgroup Proposed Definitions, October 26, 2014

Page 5 of 5

The Vinyl Institute, 1747 Pennsylvania Av, Suite 825 Washington, DC 20006.(571) 970-3392 Fax (571) 970-3271 

www.vinylinfo.org www.vinylindesign.com

Attachment B: Resin Process Types Information

VI PVC MACT Copolymers Subgroup, October 26, 2014