Matheson Gas Products - Executive Summary

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Executive Summary : 
Matheson Gas Products was founded in 1926 as a scientific gas and equipment company.  Today it is a multinational leader in specialty gases and equipment.  It focuses on global customer requirements and identifies strategically important gas technologies for development.  The Matheson maintains various facilities across the country for manufacturing, purification and distribution of industrial process gases. 
The Matheson Gas Products facility is located at 1861 Lefthand Circle, in Longmont, Colorado.  Matheson Gas Products' Longmont, Colorado facility is a production plant for Tungsten hexafluoride, general office operations, engineering services, and a Research and Development department.  The facility operates under NAICS code 32512: Industrial Gas Manufacturing.  
The plant stores liquid Hydrogen Fluoride in two "one-ton" DOT rated vessels.  These vessels are used as a feedstock for the production of Tungsten hexafluoride.  Each vessel holds approximately 1,330 
lb. of Hydrogen fluoride.  Matheson Gas Products has only one RMP regulated chemical at the Longmont, Colorado facility.  That chemical is Hydrogen Fluoride (CAS No. 7664-39-3).  The toxic endpoint for hydrogen fluoride gas is a concentration of 0.016 miligrams per liter in air. 
The production process is defined as follows.  Liquid HF is warmed by ambient temperature and by cylinder warming coils to the vapor state as HF gas.  The gas is transferred in a specialty piping system to an electrolytic cell where is comes into contact with a molten salt electrolyte.  The hydrogren fluoride gas is immediately absorbed and dissolved into the molten ammonium fluoride bath.  There is no residual hydrodgen fluoride gas after dissolution.  The molten salt is electrolyzed to produce small quantities of fluorine gas.  The fluorine gas is transferred to another vessel and reacted with a Tungsten source to produce Tungsten hexafluoride gas. 
The potential worst-case analysis required by this regulat 
ion is defined as a release of the largest container of the regulated substance over a ten minute period that results in the greatest distance to the endpoint.  Hydrogen fluoride is the only substance at the Longmont facility that is covered by this regulation.  Hydrogen fluoride could potentially be released by an accidental cylinder leak or rupture during loading and unloading of the cylinder from a delivery truck.  It could also be released by the scrubber stack in the event that the scrubber solution pump failed during a process leak event from within the facility.  In either case, the hydrogen fluoride gas could affect the surrounding population.  The existing gas management systems are suitable for minimizing the potential for an accidental release.  They consist of alarm systems, specialty piping, scrubbers, training, excess flow devices, special procedures, automatic shutoffs, and interlocked valve systems.   Matheson Gas Products has conducted Hazard and Operability Analysis s 
essions to evaluate the potentials for release of hydrogen fluoride gas and is upgrading certain systems and procedures to continually improve the gas management systems. 
Assuming a hypothetical release of gas and by using the using the EPA recommended release dispersion model, Matheson Gas Products and has evaluated the risks associated with the hypothetical release.  (Note: no actual releases have occurred).  Assuming that the contents of a cylinder could be released over a ten minute period of time, the calculations have shown that a hydrogen fluoride gas release from the facility could result in a plume that could affect the surrounding population.  The plume could extend for a distance of up to 1.8 miles and affect as many as 60,000 persons.  There are schools, residences, recreation areas, and commercial/industrial areas within the potential affected zone. 
There has been one on-site accident involving hydrogen fluoride gas.  The accident in 1996 resulted from a procedural error 
and caused a non-fatal injury to one person.  The person has fully recovered from the accident.  As a result, Matheson Gas Products improved the gas management sytems and procedures to prevent the reoccurrence of the incident. 
The facility has an emergency response program in place and trains all personnel in the safe handling of hydrogen fluoride.  An improved maintenance program is being developed to further reduce the risks. 
During the history of operation at the site the facility has been able to safely use, store, and manage hydrogen fluoride gas without an accidental release to the surrounding population. 
During the calendar year 1999, Matheson Gas Products will be evaluating additional improvements to the system including additional alarms, scrubber pumps, and improved operating and maintenance procedures.
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