McWhorter Technologies, Inc. Ennis, TX - Executive Summary |
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Executive Summary Introduction It is the policy of the McWhorter Technologies, Inc. Ennis, Texas facility management to implement the requirements of the Risk Management Program, set forth in 40 CFR 68. The intention is to minimize the risk of a hazardous material release and, in the event of a release, to protect to the utmost any human or environmental contacts both within and outside the site. MWT fully recognizes that it has a duty to protect both its employees and people outside the site that might be affected by any event on site. As such, MWTs management is committed to providing the resources necessary not only to comply with the Risk Management Program regulations, but also to prevent any accidents from occurring, whether involving Risk Management Covered Processes or not. Facility Description The facility is located at 201 Cedar Rd. in Ennis, Texas. This facility manufactures resins for use in the paint and coatings industry. In addition, the site produces resin fo r use in the composite polymer industry. The resins are produced primarily via a high temperature polymerization reaction involving certain vegetable oils, organic acids, and polyols. Reaction sizes vary from 2500 to 5000 gallons. Following reaction in the kettle, the product is transferred to a mix tank, where it is diluted with organic solvents or, in the case of composite bases, a monomer, styrene. The product is either stored on site in large storage tanks, or shipped to customers in 55 gallon drums or bulk in tank trucks. Composite polymers are also processed through an additional blending stage. One or two bases are mixed with additional styrene and catalysts or inhibitors on a microscale to achieve reactivity properties for the customer. Toluene Diisocyanate (TDI) is the chemical, on-site, that is covered by 40 CFR 68. This chemical is used in the production of polyurethane resins and in the production of powder curatives. Covered Process Description The Ennis facilit y stores and uses Toluene Diisocyanate (TDI) in several processes on site. The material is stored in quantities greater than 10,000 pounds, which causes it to be covered by 40 CFR 68. TDI is used in the manufacture of polyurethane resins and in curing agents for powder coatings. TDI is stored at temperatures ranging from 60 to 100 degrees F. The material melts at 53 to 56 degrees F. It is stored in a carbon steel storage tank capable of holding in excess of 4000 gallons. TDI liquid is heavier than water, with a specific gravity of 1.22 and the vapor is heavier than air, with a vapor density that is six times denser than air. TDI is relatively involatile, with a vapor pressure of .01 mm Mercury. At the facility there are 4 basic operations involving TDI. TDI is unloaded from tank trucks into the on-site storage tank, TDI is transferred from the storage tank to mix tanks for processing of polyurethane resins and TDI is transferred from the storage tank to the curing agent proces s for manufacture of powder curatives. Hazard Assessment Program Level 1 requirements include analyzing and reporting one worst case release scenario for each covered process. The covered process contained at the Ennis facility is the TDI process. The worst case release scenario was analyzed using the air dispersion model "SLAB" by Glenn G. Draper Engineering. TDI (Toluene Diisocyanate) was the chemical evaluated in this worst case release scenario analysis. The material is actually a mixture of 80% 2,4-Toluene Diisocyanate and 20% 2,6-Toluene Diisocyanate. Both chemicals are listed in 40 CFR 168.130 as covered toxic chemicals. In Appendix A to 40 CFR 68, both chemicals have the same toxic endpoint (.0070 mg/L). It was assumed, then, that the mixture of the two materials would have a toxic endpoint of .0070 mg/L. This value was the endpoint used in the modeling calculations. The worst case release scenario analyzed was a release of the entire contents of the TDI storage ta nk, into the surrounding concrete dike. It was assumed that the tank was filled to capacity (3,965.5 gallons, 40,369 pounds). For the purposes of the analysis, the entire contents were assumed to have spilled instantaneously and to have pooled in the containment dike. The containment structure is a concrete, diked area with concrete flooring. The structure is 35 feet long and 20 feet wide with an approximate capacity of 14,000 gallons. The surface area of the pooled TDI was, then, calculated to be 700 square-feet. The TDI was assumed to remain at 100 degrees F throughout the spill This is the maximum storage temperature of the material. The distance from the containment structure to the property line is 185 ft to the south. This is the nearest property line to the containment structure. As stated earlier, SLAB for Windows, Version 4.0 by BEE-Line Software was used to generate a computerized model of this worst case release scenario. The evaporating pool type release was used in this modeling because of the duration over which this liquid would evaporate. The evaporation rate of the TDI at 100 F was calculated to be .02 lb/min. If the entire spill were allowed to evaporate, the duration of the release would be 33,640 hours or 1401 days. The surface roughness height was 1 meter, the ambient wind measurement height was 10 meter, the ambient wind speed was 1.5 m/s, the ambient temperature was 114 degrees F, the relative humidity was 62% and the atmospheric stability class was F. The modeling was performed based on an urban landscape. There are several obstacles in the immediate area of the TDI storage tank. The projected worst case release scenario found that the distance to the toxic endpoint, listed above, was 147 ft. This distance is well within the boundaries of the plant property line. Since the toxic endpoint is within the plant property boundaries, there are no off-site consequences to a worst case release scenario of TDI, at this facility. In addition to the worst case release scenario, the facility is required, by 40 CFR 68.12, to complete the five-year accident history for each covered process. This was completed for the TDI system at the Ennis facility. In the past five years, there have been no accidents involving TDI, that had any off-site consequences, including death, injury, or response/restoration activities for exposure of an environmental receptor. Emergency Response The Ennis facility currently has a trained Emergency Response Team (ERT). This team consists of 20 site employees who have been trained to respond to any emergency at the site. Each member of the team has received 40 hour Hazardous Materials Technician Level Training. This training is refreshed every year as per regulations. In addition, several members of the team have received training in industrial fire fighting. The Ennis ERT is qualified to respond to any spill that occurs on site. In addition, the team may respond to any fire emergenc y that takes place, but will defer to the fire department upon arrival. The Ennis facility has and maintains an Emergency Action Plan (EAP). This plan details actions to be taken in the event of any emergency on the site. This includes spill, weather emergencies, fires, and health emergencies. The plan is updated once per year. The EAP contains specific instructions for handling TDI emergencies. 40 CFR 68.12 requires that all covered facilities coordinate their emergency response activities with local emergency response and planning organizations. The Ennis EAP has been implemented and coordinated with the local responding agency, the Ennis Fire Department). |