Praxair Distribution - Bethlehem, PA - Executive Summary
The Praxair Distribution facility at Bethlehem, Pennsylvania is an industrial and specialty gas plant that handles and/or stores the following substances that are regulated by the EPA's Risk Management Program rule in excess of the 10,000 pound threshold quantity listed for each substance (total process quantities in parenthesis): |
? Methane (49,000 lbs);
? Ethane (10,000 lbs);
? Ethylene (15,000 lbs);
? Trichlorosilane (41,000 lbs); and
? Ammonia (40,000 lbs).
Consequently, each process is subject to the RMP rule. The Bethlehem facility receives the substances listed above in bulk form, stores them in tanks or tube trailers, and then transfills them into smaller containers (cylinders) for distribution to customers. All of the products from the Bethlehem facility are distributed by truck. Ammonia is listed as a regulated toxic substance in EPA's Risk Management Program rule. The others above are listed as regulated flammable substances under the rule. Therefore, Praxair is require
d to report one Worst Case Scenario and one Alternate Case Scenario that represents all of the regulated flammable substances at the Bethlehem facility, as well as report one Worst Case Scenario and one Alternate Case Scenario that represents the regulated toxic material, ammonia.
The Worst Case Scenario for flammable susbstances is defined by the EPA as the release of the entire contents of the largest vessel in the process, with essentially none of the safety systems and devices that are in place to prevent such an occurrence functioning as designed. The released gas is assumed to ignite, causing a vapor cloud explosion. Given these conditions, we are then required to estimate the distance to an EPA-specified flammable endpoint, which is defined to be an overpressurization effect of 1 pound per square inch. At the Bethlehem facility, the Worst Case Scenario for flammable susbstances would involve the methane storage tank, which contains about 21,500 pounds. Using the criteria
listed above, the Worst Case Scenario would result in a maximum impact distance of about 0.23 miles to the EPA-specified endpoint. To determine this distance, we used the EPA's "RMP Off-Site Consequence Analysis Guidance."
We are also required to report one Alternative Release Scenario, or planning scenario, for the flammable processes. While an Alternative Release may never occur at a facility, it is generally accepted to be more likely, or more credible, than the Worst Case Scenario, and can be used by the facility and local response organizations to plan community emergency response activities. The RMP rule assumes more typical atmospheric and weather conditions for an Alternative Release Scenario, and allows a facility to take credit for safety devices and other mitigation systems that are in place to minimize the likelihood and effects of a release. When selecting an Alternative Release Scenario, EPA suggests a facility consider scenarios such as transfer hose releases, valve
and flange leaks, pump seal leaks, and shipping container mishaps, among others.
For the flammable processes at Bethlehem, a credible release would be a process piping failure resulting in a methane gas release at grade. An accidental release of this type may occur due to mechanical failure, corrosion, failure of a piping component (such as a joint or valve), impact by a vehicle, or other cause. At the Bethlehem facility, a release of this type could result in the released gas igniting, causing a vapor cloud explosion. The distance to the EPA-specified endpoint of 1 pound per square inch overpressure is about 0.05 miles, or about 265 feet. To determine this distance, we used the EPA's "RMP Offsite Consequence Analysis Guidance."
The Worst Case Scenario for toxic substances is defined by the EPA as the release of the entire contents of the largest vessel in our process. As with the flammable worst case scenario, we are required to assume that none of the safety systems and devic
es that are in place to prevent such an occurrence function as designed. The release is assumed to occur over a 10 minute time period, and under the most stable atmospheric and weather conditions, which minimizes the dispersion and dilution of the release and presents the absolute worst case that could possibly occur. Given all of these conditions, we are then required to estimate the distance to an EPA-specified toxic endpoint, which is defined to be a concentration of 200 ppm for ammonia. At the Bethlehem facility, the largest ammonia vessel could contain up to 35,000 pounds. Using the criteria listed above, the Worst Case Scenario would result in a maximum downwind distance of about 2.2 miles to the EPA-specified endpoint. To determine this distance, we used the EPA's "Risk Management Program Guidance for Ammonia Refrigeration."
We are also required to report an Alternative Release Scenario, or planning scenario, for the ammonia process under the RMP rule. Scenarios such as t
ransfer hose releases, valve and flange leaks, pump seal leaks, and shipping container mishaps, would be equivalent to a release from a small hole (1/4" diameter) in a tank or pipe containing ammonia at the highest system pressure. At the Bethlehem facility, a release of this type would result in a maximum downwind distance of about 0.1 miles, or 530 feet. To determine this distance, we used the EPA's "Risk Management Program Guidance for Ammonia Refrigeration."
In accordance with OSHA's Process Safety Management standard and EPA's Risk Management Program rule, the Bethlehem facility has a comprehensive accident prevention program in place to ensure the safety of our employees, our neighbors and the community around us. On a local level, this prevention program is built around process safety concepts such as:
? Documented process safety information to ensure the process design is understood and maintained throughout its life;
? Process hazard analysis to identify and control all o
f the hazards associated with handling flammable substances;
? Trained operators, using written operating procedures, to safely operate the process as intended; and
? Maintenance programs and procedures to ensure the on-going mechanical integrity of the process.
The prevention program is audited periodically, by our corporate assessment group, to ensure that the process safety concepts and practices are in place and working effectively.
As a result of our process safety and risk management practices, the Bethlehem facility has not had an accident involving any of the regulated substances in the last five years. In the event of an emergency, the facility has an emergency action plan in place, which contains procedures for employees to follow, including notification of local response agencies. All facility employees are trained in their role in the emergency action plan, and Praxair policy requires that emergency drills be conducted at least annually.
Praxair is committed to the con
tinuous improvement of its safety, health and environmental programs. The company operates under an umbrella of global corporate policies with specific program elements defined on a regional basis. As the result of recent acquisitions, detailed process safety audits have been conducted at numerous facilities throughout the company. As we ensure the process safety integrity of our facilities, we are also fine tuning the incident and near miss reporting and investigation processes. Root Cause Analysis training is being targeted within the operations and safety organizations. On a broader scale, the effectiveness, and accessibility of training is being improved. A computerized compliance management system keeps track of plant progress meeting internal and external requirements.
Praxair is a producer and distributor of industrial gases with almost 100 years of experience. We are committed to being the best performing industrial gas company in all aspects of our business, including safety
, health and environmental affairs. Praxair is a member the Chemical Manufacturers Association's Responsible Care initiative, which is intended to ensure the safe operation of chemical facilities and enhance the relationships between the chemical industry and the communities in which we operate. Internally, we use a combination of extensive engineering standards and design safety work processes, coupled with operational and personnel safety programs, to ensure the safe operation of all of our facilities. Our company-wide goal of "Zero/Zero" (which means zero accidents and zero injuries or illnesses at every location) reflects the dedication and commitment to safety throughout the entire Praxair organization.