Matheson Tri-Gas, Inc. - Executive Summary

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MATHESON GAS PRODUCTS - EAST RUTHERFORD, NJ BRANCH 
 
RMP EXECUTIVE SUMMARY 
 
BACKROUND 
 
This Matheson Gas Products facility packages compressed specialty industrial gases in Department of Transportation (DOT), National Fire Protection Association (NFPA), and Compressed Gas Association (CGA) approved containers.  This operation includes transfilling material from one cylinder to another, purification of some materials, quality control, and gas mixing to customer specifications.  The source gas for operations may be packaged in bulk containers and cylinders of varying sizes.  The finished product may include a single pure gas or a mixture of gases at varying concentrations.  Finished product is stored and shipped in cylinders with capacities of 2,000 pounds to less than 1 pound, depending on the size of the cylinder and the chemical involved. 
 
Two processes at this facility involve chemicals at quantities above the RMP threshold.  Hydrogen chloride purification, transfilling, and storage a 
re subject to RMP regulations.  Due to the regular use of bulk hydrogen chloride containers, this process has been assigned to Program 3.  Hydrogen fluoride, trichlorosilane, and phosgene cylinders are collectively stored in quantities that exceed their established EPA thresholds.  Therefore, this process is also subject to RMP regulations. Hydrogen fluoride storage typically involves 1V or smaller cylinders stored together in various designated locations throughout the facility.  Phosgene storage typically involves 1P or smaller cylinders stored together in various designated locations throughout the facility.  Trichlorosilane storage involves 550 pound cylinders stored together in various designated locations.  Due to the potential number of cylinders that can be stored together at any given time, this process has been assigned to Program 3.  
 
DESCRIPTION OF WORST-CASE AND ALTERNATIVE CASE SCENARIOS 
 
Worst Case Scenario 
 
In compliance with the Federal definition of the worst-case sce 
nario, a 10-minute release of the entire contents of the largest toxic and flammable substance container handled at the facility was modeled using RMP Comp.  Such a release would involve a bulk material unit spontaneously "splitting in half" under poor weather conditions without the use of any mitigation equipment available at the facility.  Due to the rigorous DOT, NFPA, and CGA codes and standards applied to compressed gas container service and Matheson Tri-Gas' internal standards, the likelihood of this scenario occurring is almost zero and should not be considered a credible release situation.   
 
The bulk raw material supply for the hydrogen chloride process is the largest toxic container on-site.  It holds 100,000 pounds of product and has a theoretical offsite impact of 14.0 miles.  In accordance with EPA guidelines, the toxic endpoint was modeled without considering any mitigating equipment, such as a scrubber, process monitors, or neutralization, present at the facility. 
 
A tri 
chlorosilane cylinder is the largest flammable container on-site.  It holds 550 pounds of product and has a theoretical impact of 0.03 miles.  In accordance with EPA guidelines, the estimated distance to 1 psi overpressure was modeled without considering any mitigating equipment, such as scrubbers or neutralization, present at the facility.  Trichlorosilane is stored at least 200 feet from the nearest property boundary; therefore, off-site impact will not occur. 
 
Alternative Case Scenario 
 
In compliance with the Federal definition of the alternative case scenario for toxic substances, a more realistic, yet unlikely, release scenario, having offsite impact, has been identified for hydrogen chloride, hydrogen fluoride, and phosgene.   
 
For the hydrogen chloride process, the identified scenario involves a release from the relief device located on a ton unit cylinder.  This would occur if the unit was overpressurized or the device was compromised, damaged, or defective.  The likelihood of  
this incident occurring is decreased by operator training, the stringent codes and standards of DOT, NFPA, and CGA, and Matheson Tri-Gas' internal filling procedures. 
 
This scenario involves a container holding 600 pounds of product with a theoretical off-site impact of 0.3 mile.  To provide the most conservative data, the toxic endpoint was modeled using a release rate calculated with the most conservative data and without considering any mitigating equipment, such as a scrubber, neutralization, or containment hood and kit, present at the facility. 
 
For hydrogen fluoride, the identified scenario involves a release from a vessel.  This would occur if the hydrogen fluoride contained in the cylinder decomposed.  The likelihood of this incident occurring is decreased by operator training, the slow rate of hydrogen fluoride decomposition, and periodic inventory checks.  
 
This scenario involves a container holding 100 pounds of product with a theoretical offsite impact of 0.2 mile.  To prov 
ide the most conservative data, the toxic endpoint was modeled using a release rate calculated with the most conservative data and without considering any mitigating equipment, such as a scrubber or containment hood and vessel present at the facility.  
 
For phosgene, the identified scenario involves a release from a vessel.  This would occur if the valve were compromised, damaged, or defective.  The likelihood of this incident occurring is decreased by operator training, and DOT, NFPA, and CGA codes and standards for cylinder valves.  
 
This scenario involves a container holding 85 pounds of product with a theoretical offsite impact of 0.3 mile.  To provide the most conservative data, the toxic endpoint was modeled using a release rate calculated with the most conservative data and without considering any mitigating equipment, such as a scrubber or containment hood and vessel present at the facility. 
 
In compliance with the Federal definition of the alternative case scenario for flammab 
le substances, one more realistic, yet unlikely, release scenario for all flammables, having offsite impact, has been examined by the facility.  Based on the expertise of the members of the facility staff, which exceeds 20 years, and the physical properties of the chemical, an alternate case scenario with off-site impact could not be identified for trichlorosilane.  However, a credible scenario, a process line leak, was identified and modeled. 
 
This scenario involves a container holding 550 pounds of product with a theoretical impact of less than 0.1 mile.  Considering the worse case scenario modeled for this chemical produced an impact of 0.03 mile, it can be assumed that this scenario would produce an impact less than the worse case.  To provide the most conservative data, the toxic endpoint was modeled using a release rate calculated with the most conservative data and without considering any mitigating equipment, such as a scrubber or containment hood, present at the facility. 
 
ACC 
IDENT HISTORY 
 
This facility has not had an accident involving the regulated process in the last five years. 
 
PREVENTION PROGRAM and EMERGENCY RESPONSE 
 
Compressed gas cylinders are manufactured and maintained to the exacting codes and standards of the DOT, NFPA, and CGA.  Cylinder construction is mandated in all aspects including metallurgy, wall thickness, and design pressure.  The cylinder design pressure must exceed the fill pressure by a certain percentage.  These codes and standards have been established to insure that compressed gas cylinders are designed to withstand extremes of operation and overpressure conditions.  Each cylinder must be tested and re-qualified every 5 years.  Appurtenances such as safety relief devices and valves must meet stringent manufacturing standards as well.  In addition to these codes and standards, Matheson Tri-Gas has an established policy of filling cylinders to a pressure below the DOT approved fill pressure.  Compliance with these standards, cod 
es, and policies significantly reduces the likelihood of a catastrophic failure of a compressed gas cylinder. 
 
In addition to the integrity of the cylinder and its components, a primary element of this facility's prevention program is its experienced operators.  Not only are they certified with the knowledge, skills, and abilities to perform their duties safely, but they are also able to assess and resolve possible abnormalities before they result in a release.  Operator experience ranges from 6 months to more than 20 years.  Operators receive refresher training and requalification annually.  The cylinder storage areas are routinely inspected.  Finally, the facility employs a competent maintenance staff to resolve mechanical problems and improve current systems. 
 
This facility maintains numerous safeguards to mitigate and control potential releases of materials.  Three scrubbing units and numerous neutralizing tanks are present at the facility to capture potential emissions at all appr 
opriate filling and process endpoints.  A scrubber hood, containment vessel, ton unit kit, and railcar kit are available to contain potential releases.  Sprinklers are located in areas that may contain flammable materials.  Process monitors are located around the hydrogen chloride bulk raw material container.  The operation of the bulk hydrogen chloride container refrigeration unit is monitored 24-hours a day.  Process equipment in corrosive gas service is regularly replaced.  Finally, a security officer monitors the site during non-working hours.  If an abnormal condition is detected, the officer immediately contacts the appropriate site personnel.    
 
This facility maintains an emergency response team that has been trained in accordance with OSHA 29 CFR 1910.120 Section Q (6)(iii).  Each member receives refresher training and requalification annually. Annual internal drills and drills coordinated with the local authorities focus on alarm identification, use of emergency equipment, re 
scue procedures, and other specialized training topics.  Equipment necessary to quickly respond to an incident is kept at the facility, including monitors, a scrubber containment hood, and containment vessels to capture emissions from leaking cylinders.  During an incident, the facility team assumes the role of primary responder.  Local emergency response agencies will be called, if necessary. Contact with the City is made by phone, and the public authorities are responsible for alerting area residents and businesses.  
 
PLANNED UPGRADES 
 
The facility is currently in the final stages of constructing a new hydrogen chloride process detection system.  The new system will expand the current system's monitoring capacity and function.  The facility is also involved in the on-going process of expanding and formalizing its maintenance and training programs.
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