Tekni-Plex, Inc. - Somerville - Executive Summary |
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Background The Tekni-Plex facility in Somerville, New Jersey produces extruded polystyrene foam products using difluoroethane as the expanding agent. The facility consists of manufacturing areas, storage warehouses, and offices, with a difluoroethane storage tank located outside of the building. The facility operates as much as 24-hours per day, 365 days per year and employs approximately 210 people. Our foam products are used in products such as food packaging trays. Process Description Difluoroethane is the only material at the facility subject to the United States Environmental Protection Agency's (USEPA's) Risk Management Plan (RMP) program. Difluoroethane is received by Tekni-Plex as a liquid in tank trucks and is unloaded into a storage tank located outside. The maximum difluoroethane storage quantity is 88% of the tank design capacity to allow room for emergency expansion under emergency situations. Difluoroethane is pumped through a controlled system into the foam produ ction building. The difluoroethane is then used to expand melted plastic within the extruders to create the desired foam product. A number of valves, controllers, and instruments control and monitor the pressure and flow of the difluoroethane throughout the process. The primary hazards associated with the difluoroethane system are releases that could occur outside or inside the extrusion building that could lead to a fire or explosion. The possible causes of releases include pump failure, failure of piping or tubing, failure of valves or instruments, storage tank leakage, or failure of equipment used for tank filling. Five Year Accident History The facility has not experienced any significant accidents associated with handling difluoroethane in the last five years. A significant accident would be one causing some type of off-site impact or on-site injuries or significant property damage. Worst-Case Scenario USEPA accident prevention regulations require companies to analyze wha t is defined as a worst-case release scenario. For Tekni-Plex, the worst-case scenario as defined by the USEPA is the sudden loss of containment of all of the difluoroethane contained in the aboveground storage tank. This would mean some type of catastrophic failure of the tank. RMP regulations require the assumption that the numerous safety and alarm systems Tekni-Plex has in place fail to operate as designed. It is also required to assume that this hypothetical release occurs during the least likely weather conditions, meaning very low wind speeds and a stable, or stagnant atmosphere. This worst-case scenario therefore assumes that several highly unlikely events occur simultaneously: -Catastrophic failure of the difluoroethane tank. -All of the automated safety and alarm system fail to operate. -Failure of our trained operators to respond appropriately. -The event occurs during the least likely meteorological conditions. While this event is highly unlikely, we are required to analyze such a release and to estimate the potential effect on the surrounding community. Tekni-Plex used a state-of-the-art model to estimate the effect of this hypothetical release, the Baker-Strehlow Model a commercially available model in the Breeze Haz Fire/Explosion software program. The model predicts the distance to which an explosion or blast wave equivalent to one pound per square inch (psi) would reach. One psi overpressure is set by the USEPA as the point of concern for materials presenting a potential explosion hazard. An overpressure of one psi would typically shatter windows, but not cause serious structural damage to buildings. The difluoroethane worst case scenario results show that there are no off-site buildings, commercial or residential, or other public receptors within the one psi zone. Program Level Description The worst-case results categorize this process as a USEPA Program 1 facility, however, the facility has filed as a Program 3 facility with the New Jersey Department of Environmental Protection (NJDEP), as required. NJDEP requires Program 3 submission because the facility is subject to the Occupational Safety and Health Administration's (OSHA's) Process Safety Management (PSM) standard. Release Prevention Program Tekni-Plex's Plant Manager has the overall responsibility for ensuring that the facility operates in a safe and reliable manner. This responsibility includes overseeing the implementation of the RMP. Tekni-Plex has invested significant manpower and resources to prepare and implement this RMP and the related Process Safety Management (PSM) program to address the potential hazards associated with difluoroethane at the Somerville facility. The facility's RMP/PSM program contains a Prevention Program that focuses on prevention of releases. The Prevention Program includes the use of appropriate equipment design standards, safety valves and instruments, written operating procedures, employee and contractor training, regu lar equipment inspection and maintenance, and periodic program auditing to reduce the likelihood of difluoroethane releases occurring. The facility has compiled process safety information and has conducted a process hazard analysis (PHA) review of the difluoroethane system. The difluoroethane storage tank was designed and constructed in accordance with the American Society of Mechanical Engineers (ASME) code for pressure vessels. The difluoroethane system was designed and constructed in accordance with the applicable portions of the National Fire Prevention Association (NFPA) 58 LP-Gas Code and is equipped with a variety of modern safety equipment. The facility has implemented administrative controls and procedures to aid in the prevention of releases from the operation of the difluoroethane system. Personnel operating and maintaining the difluoroethane system undergo regular training. The training program includes initial training as well as periodic refresher training and train ing updates when major process or equipment changes are made. Written operating procedures are used to standardize the procedures for startup, normal operation, normal shutdown, and emergency shutdown. Tank loading is conducted by contract truck drivers certified to safely handle LP-gases and monitored by trained Tekni-Plex personnel. The facility conducts regular planned inspection and preventative maintenance of the difluoroethane system equipment. Release Detection and Emergency Response The plant has 16 gas detectors located throughout the facility. The detectors are designed to warn an operator of a potential difluoroethane release and automatically shut down the process under certain conditions. These include gas detectors on relief valve vent lines to indicate when a safety relief device has activated. Automatic sprinkler systems are located throughout the building areas where difluoroethane is present and at the difluoroethane storage tank. The facility has an emergenc y response plan that addresses emergency response procedures in the event of a leak, fire, or explosion. According to the emergency response plan, Tekni-Plex personnel are required to contact the North Branch Fire Department in the event of any emergency. The facility has coordinated with the North Branch Fire Department with regard to emergency response on the difluoroethane system. For additional information on what actions to take in the event of an emergency, contact the North Branch Fire Department. Additional Steps to Improve Safety Tekni-Plex has created a culture for continuous improvement of its safety systems and programs. We have trained our employees to safely perform their assigned tasks. We also encourage our employees to suggest changes or improvements that will help to increase the safety of the facility. We perform inspections and preventative maintenance to minimize the potential for unanticipated failure of our equipment. Our systems and programs are audited , typically by an outside company, at least once per year to evaluate their effectiveness. We have recently reviewed and modified elements of our Prevention Program. We are presently reviewing the recommendations identified during Process Hazard Analysis of our equipment and procedures, performed by an independent expert with the participation of our facility personnel. |