Fiberglass Reinforced Plastics (FRP) and Cultured Marble
  Plants

TNRCC Rule 116.111(3) in Regulation VI requires that Best
Available Control Technology (BACT) be applied to all
facilities that must obtain a permit.  This BACT determination
is made on a case-by-case basis and we encourage discussion
between applicants and the TNRCC to determine BACT for each
facility.  Current BACT practices for the FRP industry are:  

1.  Low volatile organic compound (VOC), usually styrene,
    content resin.  
2.  Vapor suppressed resin.  
3.  Enclosed molding process, i.e. resin injection
4.  At least ninety-five percent air filter efficiency
5.  Low vapor pressure cleaning solvents:  
    a.  Acetone usage must be less than one percent of total
        resin usage.  
    b.  Acetone replacement compounds with a vapor pressure
        less than one millimeter Hg.  
    c.  Water-based compounds with a VOC content less than
        five percent by weight.  
6.  An air ventilation system providing an average of at least
    100 feet per minute (fpm) through all building openings. 
    This airflow will minimize fugitive emissions; thereby,
    reducing off-property styrene concentrations.  
    (Highly recommended) 
7.  Vertical airflow stacks with stack heads that conform to
    one of the designs found in the American Conference of
    Governmental and Industrial Hygienists.  
8.  Total VOC emissions greater than eighty tons per year may
    require add-on controls.  

These levels are guidelines to show the applicant what the
TNRCC is currently considering as BACT; however these control
levels are subject to change.  Each applicant is required to
submit a detailed BACT analysis if proposing any controls not
listed above.  The BACT discussion format needs to follow the
TNRCC "three tier" method or the EPA "top down" method. 
Regardless of the analysis used, applicants must supply
control equipment cost estimates, amortized over the life of
the equipment, and annualized operating costs.  The EPA
document OAQPS Control Cost Manual, EPA 450/3-90-006,
describes how to perform the analysis and provides the format
to use for presentation of results.  This manual can be
obtained by writing the National Technical Information Service
(NATS), 5285 Port Royal Road, Springfield, Virginia  22161 or
telephoning 703-487-4650.