Praxair Distribution - North Royalton, OH - Executive Summary

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The Praxair Distribution facility at North Royalton, Ohio is an industrial and specialty gas plant that stores and handles the following substances that are regulated by the EPA's Risk Management Program rule, in excess of their threshold quantity: 
 
7 Acetylene; and 
7 Propylene. 
 
The North Royalton facility receives propylene in bulk form, stores it in a large tank, and then transfills it into smaller containers (cylinders) for distribution to customers.  All of the products from the North Royalton facility are distributed by truck.  Propylene is listed as a regulated flammable substance in EPA's Risk Management Program rule, with a threshold quantity of 10,000 pounds.  The propylene storage and transfilling process at the North Royalton plant contains about 50,000 pounds of product, and therefore is subject to the RMP rule. 
 
The North Royalton facility manufactures acetylene gas by reacting calcium carbide and water.  The acetylene gas is purified and then compressed into specially de 
signed acetylene cylinders.  These cylinders can be filled and used individually, or the product can be filled into acetylene cylinders on flatbed trailers.  On an acetylene trailer, the individual cylinders are connected by a piping manifold, which allows acetylene gas to be withdrawn from the entire bank of cylinders.  Acetylene is also listed as a regulated flammable substance in EPA's Risk Management Program rule, with a threshold quantity of 10,000 pounds.  The acetylene process at the North Royalton plant contains about 24,000 pounds of product, and therefore is subject to the RMP rule. 
 
Under the RMP rule, Praxair is required to report one Worst Case Scenario that represents all regulated flammable substances at the North Royalton facility.  The Worst Case Scenario 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 North Royalton facility, the Worst Case Scenario involving a regulated flammable substance would be the failure of the propylene storage tank, which holds about 47,000 pounds of product.  Using the criteria listed above, the Worst Case Scenario would result in a maximum impact distance of about 0.30 miles to the EPA-specified endpoint.  To determine this distance, we used the EPA's "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 th 
e 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 the North Royalton facility, a credible release would be a process piping failure resulting in an acetylene gas release at grade.  An accidental release of this type may occur due to mechanical failure, corrosion, failure of a piping component (such as joint or a valve), impact by a vehicle, or other cause.  At the North Royalton facility, a release of this type could result in the released gas ign 
iting, causing a vapor cloud explosion.  The distance to the EPA-specified endpoint of 1 pound per square inch overpressure is 0.05 miles, or about 265 feet.  To determine this distance, we used the EPA's "RMP Offsite Consequence Analysis Guidance." 
 
In accordance with OSHA's Process Safety Management standard and EPA's Risk Management Program rule, the North Royalton 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: 
 
7 Documented process safety information to ensure the process design is understood and maintained throughout its life; 
7 Process hazard analysis to identify and control all of the hazards associated with handling flammable substances; 
7 Trained operators, using written operating procedures, to safely operate the process as intended; and 
7 Maintenance programs and procedures to ensure t 
he 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 North Royalton facility has not had an accident involving acetylene or propylene 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 continuous 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 rec 
ent 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 relat 
ionships 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.
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