Matheson Gas Products, LLC - Executive Summary |
|
MATHESON GAS PRODUCTS - GLOUCESTER, MA 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 manufacturing, transfilling material from one cylinder to another, purification of some materials, quality control, and gas mixing to customer specifications. The source gas for operations is manufactured at the facility and placed in cylinders. This material is then transfilled into other cylinders. 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 60 pounds to less than 1 pound, depending on the size of the cylinder and the chemical involved. Arsine cylinders are collectively stored in quantities that exceed the established EPA thresh old. Therefore, this process is subject to RMP regulations. The arsine process typically involves 1A or smaller cylinders stored together in various locations throughout the facility. 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 scenario, a 10-minute release of the entire contents of the largest container of arsine handled at the facility was modeled using RMP Comp. Such a release would involve a cylinder 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 cylinder service and Matheson Gas Products' internal standards, the likelihood of this scenario occurring is almost zero and should not be considered a credible release situation. The largest container of arsine located at the facility holds 60 pounds of product and has a theoretical offsite impact of 1.6 miles. In accordance with EPA guidelines, the toxic endpoint was modeled without considering any mitigating equipment, such as a scrubber, process monitors, or containment hood, present at the facility. Alternative Case Scenario In compliance with the Federal definition of the alternative case scenario, a more realistic, yet unlikely, release scenario, having offsite impact, has been identified for arsine. A release of arsine from a vessel is the identified scenario. This would occur if the valve were compromised, damaged, or defective. The likelihood of this incident occurring is decreased by operator training, SDS packaging of certain cylinders, and DOT, NFPA, and CGA codes and standards for cylinder valves. This scenario involves a container holding 60 pounds of product with a theoretical offsite imp act of 0.2 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, process monitors, or containment hood and vessel, present at the facility. ACCIDENT 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. Ap purtenances such as safety relief devices and valves must meet stringent manufacturing standards as well. In addition to these codes and standards, Matheson Gas Products has an established policy of filling cylinders to a pressure below the DOT approved fill pressure. Compliance with these standards, codes, 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 3 months to more than 20 years. Operators and area supervisors receive refresher training and requalification annually. An operator or supervisor cannot perform their job duties unless they h ave successfully completed initial training or requalification. After filling, each cylinder is leak checked. Cylinders are stored with protective caps covering the valve. The cylinder storage areas are routinely inspected, and certain areas are equipped with arsine monitors. Extremely sensitive arsine detection tape is used around each cylinder neck and valve prior to shipping. 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. Equipment necessary to quickly respond to an incident is kept at the facility, including monitors, a scrubber containment hood, and a containment vessel to capture emissions from leaking cylinders. The Gloucester Fire Department is invited to various training sessions held at the facility and walk-throughs to acquaint the staff with the facility. Contact with the City is made by phone, and the public aut horities are responsible for alerting area residents and businesses. PLANNED UPGRADES The facility is currently in the process of designing and constructing a new arsine process detection system. The new system will expand the current system's monitoring capacity and function. |