Sumitomo Sitix Silicon, Inc., Cincinnati Division - Executive Summary

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The Sumitomo Sitix Silicon facility, located on Grandin Road in Maineville, Ohio, is designed to facilitate the manufacture of silicon wafers that are used in the electronic industry.  The general public would most likely encounter products made from these wafers in integrated circuits found in automobiles, pace makers, telecommunication equipment, and endless forms of electrical switches and controls, both consumer and industrial.    
In brief and greatly simplified, silicon wafers are made by a process in which crystal silicon ingots are polished to create a defect-free surface.  Then hydrogen chloride is introduced in the Epitaxail Silicon process as a wafer-cleaning agent, followed by trichlorosilane, which deposits another layer of silicon onto the wafer. 
In response to the regulations enumerated by the Clean Air Act (CAA), as specified in the Environmental Protection Agency (EPA) rules on May 24, 1996, Sumitomo Sitix Silicon, Inc. submits its 
Risk Management Plan (RMP).  This RMP complies with the requirement to publish its plans to prevent accidental releases of regulated substances and to reduce the severity of the releases that do occur.   
The Process Safety Management team at Sumitomo Sitix Silicon (SSAC) has determined that the following chemicals and processes are subject to compliance with the EPA Risk Management Plan: 
7 Hydrogen chloride (HCl), bulk storage and delivery 
7 Trichlorosilane (TCS), bulk storage, delivery, and reclaim 
Accidental Release Prevention and Emergency Response Policies 
The prevention of accidental release of hazardous substances is of major concern for Sumitomo employees.  The objectives of SSAC's training programs are the preparation of employees to operate equipment properly and safely and to be alert to evidence of accidental chemical leaks and releases.  
Every person working at Sumitomo Sitix Silicon, Inc. (hereafter designated as SSAC), and including directors, managers, supervisors, 
operators, mechanics, etc., is committed to safety procedures that protect on-site personnel.  As stated in Standard Operating Procedures 7501P, PSM-Process Safety Management Employee Participation Plan, "Process safety is the responsibility of all employees that are involved with processes and systems that affect highly hazardous chemicals."  SSAC complies with all preventative safety programs as defined by OSHA's Process Safety Management regulations. 
Management is committed to employee safety and the implementation of safe procedures.  This is further demonstrated by the approval and support of various Standard Operating Procedures that proscribe specific safety practices, such as "Hot Work," "Evacuation Plans," and "Lockout/Tagout of Hazardous Energies." 
Management strongly supports the selection and training of the Employee Response Team (ERT), whose members are the first responders to any emergency incident.  First established in 1991, the ERT has been at the center of SSAC's  
emergency response programs.   
Sumitomo's Facility and On-site Regulated Substances 
The EPA has designated hydrogen chloride and trichlorosilane as regulated substances.  Regulated substances are defined as "toxic and reactive highly hazardous chemicals that present a potential for a catastrophic event at or above a specified threshold quantity."  
SSAC maintains between 100,000 and 180,000 pounds of trichlorosilane on-site; 5,000 pounds is the threshold quantity.   This is distributed between two bulk tanks, two bubbler vessels, two condenser vessels, one reclaim TCS tank, and associated piping.  SSAC maintains between 20,000 to 42,000 pounds of hydrogen chloride on-site; 5,000 pounds is the threshold quantity.  
As a consequence of these amounts of hazardous chemicals at its Maineville facility, SSAC has, over the past three years, conducted extensive process hazard assessment studies.  These ensure that rigorous safety standards are observed in all phases of its manufacturing oper 
ations and that all possible efforts are made to protect the surrounding communities from possible exposure to a release of a hazardous substance. 
Release Scenario(s) 
Worst-case release scenario for hydrogen chloride (anhydrous-Hydrochloric acid): Our worst-case scenario is the failure of one 3,000-pound storage vessel containing 3,000 pounds of hydrogen chloride, resulting in a vapor cloud release.  The toxic cloud formed by the release of hydrogen chloride would reach offsite endpoints and nearby public receptors.  
(1) Alternate-case release scenario for hydrogen chloride (anhydrous-Hydrochloric acid): If the transfer hose that connects the bulk HCl trailer manifold to the in-house HCl system were to fail, 940 pounds of hydrogen chloride vapor would be released.  Because of our rural location and the limited endpoint, the impact of such a release would affect only near-by offsite residences.   
SSAC has taken these steps to make this alternate-case release unlikely:  
7 The transf 
er line is inspected and leak checked by the process chemical operator during daily rounds. 
7 The transfer line is replaced by a new line every six months. 
7 Chocks are placed under the HCl bulk trailer wheels to prevent accidental trailer movement. 
7 A process chemical operator is present to supervise the hook up of a new HCl bulk trailer and the release of a trailer after being emptied. 
(2) Alternate-case release scenario for hydrogen chloride (anhydrous-Hydrochloric acid): If there would be a leak in the HCl piping system, 164 pounds of hydrogen chloride vapor would be released.  Since this release is relatively small, this alternate-case scenario would not affect anyone outside our property. 
SSAC has taken these steps to make this alternate-case release unlikely:  
7 The HCl piping system is inspected and leak checked by the process chemical operator during daily rounds. 
7 The mechanical integrity of the HCl piping system is checked annually. 
7 The piping system is inspected for  
pipe wall thickness every five years.                                                      
(3) Alternate-case release scenario for hydrogen chloride (anhydrous-Hydrochloric acid): If there would be a rupture disk leak in the HCl bulk trailer, 924 pounds of hydrogen chloride vapor would be released.  Since this release is relatively small, this alternate-case scenario would have no offsite impact. 
SSAC has taken these steps to make this alternate-case release unlikely:  
7 The process chemical operator inspects the HCl bulk trailer upon arrival. 
7 Each HCl bulk trailer is tested every five years for compliance with DOT safety regulations. 
Flammable: Worst-case release scenario for Trichlorosilane [Silane, trichloro-]: If a trichlorosilane vapor cloud explosion were to occur, the resulting fire would have no offsite i 
mpact.  Based on the PHAST modeling software, a maximum of 48,000 pounds of TCS would be released.   
The concrete dike that is constructed around the TCS bulk tank farm would contain a TCS fire.  Other passive mitigation includes the blast wall located between the TCS tank farm and the SSAC plant.  The TCS bulk tank area is protected by an automatic sprinkler system.  In addition, SSAC's Emergency Response Team has a foam cart readily available to spray a layer of foam over a TCS fire.  The Emergency Response Team is trained in using foam as a fire retardant system. 
Accidental Release Preventive Program 
SSAC has instituted practices and procedures to help prevent accidental release of hazardous substances, including the following: 
7 The presentation of process safety information so that many users, including hazard assessment team members, program and procedures trainers, contractors working with process chemicals, and emergency response personnel, can understand the precautions to 
take when working with hazardous substances. 
7 The institution of regular process hazard analyses to identify processes that are covered by the OSHA standard and to ensure that proper precautions are taken to protect employees and the public from the consequences of a catastrophic release of hazardous substances. 
7 Daily visual inspections of all systems including piping, valves, gauges, and controllers to ensure mechanical integrity.  Daily measurements of systems' parameters, recorded via a data logger, of pressure, volume, flow, inventory, and usage levels; conditions of on-line equipment; percentage of valve positions open, etc. 
7 Involvement of employees in developing and implementing process safety programs and hazard analyses. 
7 Specified standard operating procedures for performing all manufacturing and facilities operations at the SSAC facility, with special attention being paid to accuracy and understandability of instructions.  All specifications include a specific safety s 
7 Mechanical integrity programs of physical components for all systems combined with preventive maintenance schedules and guidelines  
7 Established stringent guidelines for the selection, regulation, training, and evaluation of on-site contractors to protect the health and safety of facility employees as well as the contractors themselves. 
7 Procedure for investigating incidents and accidents to prevent similar events from happening. 
7 Activation of an emergency action plan in case of an accidental release of a hazardous chemical to provide directions for protecting employees, containing hazardous spills, contacting offsite agencies for assistance, communicating with the media, and handling the subsequent cleanup following an incident. 
7 Intensive initial training program for new employees with follow-up of refresher training and safety and incident reviews. 
7 Establishing procedures for performing hot work and safe work. 
7 Planning how best to institute change in established s 
ystems, procedures, and equipment so employees will be informed of the reason for change, trained in working with the changed situation, and protected from possible injury when the change is in effect. 
Five-year Accident History 
We are pleased to report that there has been no accidental release of any regulated chemical at SSAC during the past five years. 
Emergency Response Program 
The Emergency Response Team (ERT) has the primary responsibility for responding to an emergency incident.  The ERT Chief, upon receiving notification of an emergency, assesses the situation and determines if the ERT can handle the situation or if outside help needs to be requested.   
The ERT Chief works with the Safety and Health Manager in planning, developing, and holding training sessions for ERT members.  He/she supervises emergency response drills for SSAC employees and ERT members. 
After every ERT response to an incident, the ERT Chief completes the ERT Incident Report Form and participates in th 
e post-response critique, in which SSAC management and local responders participate. 
Improving Safety at SSAC 
SSAC is continually looking for ways to improve safety conditions and to prevent the accidental release of hazardous substances at its manufacturing facility.  The Preventive Maintenance program, in conjunction with SSAC's Mechanical Integrity procedures, provides for continuous, regular inspection of the plant's physical equipment, and for replacement of equipment as necessary. 
Future enhancements include improvements in engineering controls to limit the maximum flow of HCl that can flow through the HCl piping manifold. 
The computer-based Preventive Maintenance (PM) program triggers the routine inspection of all regulated systems' equipment, including systems valves, gauges, flanges, piping supports, connectors, etc.  The PM program also schedules the replacement of specified components as determined by the life-expectancy of the particular component.   
SSAC maintains a c 
ontinuous training program for all Emergency Response Team (ERT) members, who are trained in all aspects of emergency recognition and response.  This training focuses on how to safely and effectively control emergency situations to minimize personal injury, environmental effects, and property loss.  Required refresher training includes hazardous materials technician training, CPR training and basic First Aid for ERT members.  Regularly scheduled monthly meetings provide the opportunity for additional group training in new procedures.
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