Executive Summary 17-JUN-1999
Air Products, Hometown, Tamaqua, PA 18252
Executive Summary
Air Products and Chemicals, Inc.
Hometown Electronics Specialty Gases Facility
1. Accidental release prevention and emergency response policies: At this facility, we produce fluorine and fluorine derivative gases for packaging into compressed gas cylinders or tube trailers. During the fluorine manufacturing process, we use hydrogen fluoride as a raw material. We also re-package anhydrous hydrogen chloride, ethyl chloride, and methyl chloride from bulk storage tanks. Anhydrous ammonia is used in a reaction fluorine to produce one of the fluorine derivative gases. All six chemicals listed above, in the amounts handled by our facility, are considered hazardous by the EPA. It is our policy to adhere to all applicable Federal and state rules and regulations. Air Products manages the safety of the regulated processes by means of operating procedures, equipment testing and inspections, safety devices (e.g., alarms, shutdowns, instrumentation, relief devices) inherent in the design of this facility and other controls and systems designed to prevent accidental releases of hazardous chemicals. Safe work practices and training of our personnel supplement the inherent safe design of the plant.
Our emergency response program is based upon OSHAs HAZWOPER regulation. The emergency response plan includes procedures for the notification of the local fire authority and Hazardous Materials unit so that appropriate measures can be taken by local emergency responders to control accidental releases.
This document has been prepared in accordance with the EPAs Risk Management Plan regulation (40 CFR, Part 68). The substances and processes considered during the preparation of this RMP and the scenarios described were selected based on criteria established in the regulation.
2. The stationary source and regulated substances handled: The primary purpose of this facility is the production of specialty and electronic gases and chemicals. A majority of these gases are derived from fluorine, which is generated at the site in electrolytic cells by electrical decomposition of hydrogen fluoride. Hydrogen is generated as a by-product, which is vented in small amounts to the atmosphere. The electrolysis takes place in a cell containing hydrogen fluoride with dissolved potassium bifluoride. The majority of the fluorine is cooled by liquid nitrogen to remove residual hydrogen fluoride and potassium fluoride carried over from the electrolytic cells. After these impurities are removed, the gas is compressed for distribution to the various fluorine users throughout the facility.
The hydrogen fluoride is also transfilled into smaller containers, or cylinders. The hydrogen fluoride is brought on site by railcar and loaded into a stationary storage tank. The hydrogen fluoride is pumped into cylinders or ton containers, which are stored and maintained on site for shipment to customers.
This facility also re-packages anhydrous hydrogen chloride. The hydrogen chloride is brought on site by railcar. From the railcar, it is transferred through a series of heat exchangers and pumps to the tube trailers and cylinders. Also, tube trailers and cylinder storage of hydrogen chloride are maintained.
Bulk quantities of ethyl chloride and methyl chloride are brought on site primarily by railcar and loaded into storage tanks. From there, the material is pumped into cylinders, which are stored and maintained on site for shipment.
Anhydrous ammonia is also re-packaged into cylinders. The ammonia is brought on site by tank truck and pumped into a stationary storage tank. The ammonia is pumped into cylinders, which are stored and maintained on site for shipment to customers. Anhydrous ammonia is also used as a raw material in the production of nitrogen trifluoride (NF3). NF3 is made by introducing fluorine gas into ammonium bifluoride. Ammonia is transferred under its own storage tank pressure, vaporized, and fed to the system to control the hydrogen fluoride concentration in the product, and to replenish the ammonium bifluoride.
The regulated substances handled at this facility are fluorine, hydrogen fluoride, anhydrous hydrogen chloride, ethyl chloride, methyl chloride, and anhydrous ammonia. The maximum amount of these substances at this facility are:
3. The worst-case release scenario(s) and the alternative release scenario(s), including administrative controls and mitigation measures to limit the distance for each reported scenario:
The "worst-case scenario" (WCS), as defined by EPA, is associated with anhydrous hydrogen chloride and is a catastrophic failure in the hydrogen chloride railcar. The entire anhydrous chloride inventory of 155,00 pounds is assumed to be released and to vaporize. The maximum distance to the EPA defined toxic endpoint (ERPG-2) of 20 ppm for this WCS reaches receptors off-site. Although we have other "active mitigation" systems directed at preventing such releases and controlling the consequences, no credit for active mitigation measures were taken into account in evaluating this WCS.
The "worst-case scenario", as defined by the EPA, associated with a release of flammable substances at this facility is a vapor cloud explosion (VCE) involving the maximum inventory of the ethyl chloride storage tank. A full vessel inventory of 89,000 pounds is assumed to be released and ignite, resulting in a VCE. The maximum distance to the EPA defined endpoint (1 psi overpressure) for this reaches receptors off-site. Although we have active controls directed at preventing such releases and controlling the consequences, no credit for active mitigation measures were taken into account in evaluating this WCS.
"Alternative case scenarios" (ACS) were done for each of the five toxic chemicals at the site. For anhydrous hydrogen chloride, the ACS is the failure of a safety device on a single tube of a tube trailer, resulting in a release of 3000 pounds of hydrogen chloride over a 15-minute period. The 15-minute release duration is the approximate time it takes for the tube to empty. The maximum distance to the EPA defined toxic endpoint of 20 ppm for this ACS reaches receptors off-site.
For fluorine, the ACS is also a failure of a safety device on a single tube of an Airopak tube trailer. This trailer contains a mixture of 25% (by weight) of fluorine in nitrogen. Because of the larger orifice size in the tube safety device, the tube empties in less than a minute, releasing 270 pounds of fluorine in that time. The maximum distance to the EPA-defined toxic endpoint of 2.5 ppm for this ACS reaches receptors off-site.
The ACS for hydrogen fluoride is a failure of a 2-inch coupling (Barco joint) on the railcar unloading line should the railcar move while connected. About 500 pounds of hydrogen fluoride would be released in a 3-minute period. The duration is based on an operator (always in attendance during the offload) pushing the emergency stop button which closes an air-operated valve on the car end of the liquid piping.
Additionally, an HF monitoring system could also initiate shutdown of the system. The maximum distance to the EPA-defined toxic endpoint of 20 ppm for this ACS reaches receptors off-site.
Failure of the 1 =-inch methyl chloride railcar unloading flexhose because the railcar moves while connected has been selected as the ACS for this toxic chemical. About 2200 pounds of methyl chloride is released over a 10-minute period. This duration is based on the amount of time it takes an operator to detect the release and pushing the emergency stop button, which closes an air-operated valve on the railcar end of the liquid piping. The maximum distance to the EPA-defined toxic endpoint of 400 ppm for this ACS does not reach any receptors off-site.
The ACS for anhydrous ammonia is a failure of the tank truck transfer hose. About 5000 pounds of ammonia would be released over a 3-minute period. The duration is based on a tank truck driver (always in attendance during the offload) pushing the emergency stop button which closes a valve on the truck end of the transfer hose. The maximum distance to the EPA-defined toxic endpoint of 200 ppm for this ACS reaches receptors off-site.
The ACS for the flammable substance at this facility is a vapor cloud explosion (VCE) involving the entire contents of the ethyl chloride storage tank. The release is caused by a vacuum condition being created in the tank, which causes an opening of about 24 square inches. The entire contents of the tank, about 89,000 pounds, is released over a period of 40 minutes through this opening. The maximum distance to the EPA defined flammable endpoint of 1 psi overpressure for this ACS does not reach receptors off-site.
4. The general accidental release prevention program and specific prevention steps:
The facility developed prevention program elements based on the Federal EPAs Accidental Release Prevention Plan and OSHAs Process Safety Management (PSM) regulation. This facility was designed and constructed to comply with applicable state and industry codes.
5. Five-year accident history:
This facility came on line in March of 1973. In the last five years, there have been no accidents involving or accidental releases of fluorine, hydrogen fluoride, anhydrous hydrogen chloride, ethyl chloride, methyl chloride, and anhydrous ammonia that resulted in any deaths, injuries, or significant property damage on site, or known off-site deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage.
6. The emergency response program: Employees that are members of the on-site emergency response team at the facility will respond to emergencies beyond initiating emergency response from outside agencies. All facility employees have been trained to OSHAs HAZWOPER, First Responder Awareness Level in order to identify the need for an initiated response. Retraining is conducted annually.
The facility maintains an Emergency Procedure Manual that contains specific procedures for employees to take in the event of an emergency or accidental release. This information also contains the names and numbers of responding outside agencies. Emergency actions and response for both flammable releases and toxic releases have been coordinated with Hometown Fire Company, Quakake Fire Company, and Ryan Township Fire Company, as well as the Ryan Township Ambulance and Rescue Squad. Annual drills are held in order to review these activities with the responsible responding units.
7. Planned changes to improve safety:
The facility resolves recommendations from PHAs and Incident Investigations, some of which may result in modifications to the plant design and operating procedures.
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This site was updated on June 18, 1999
RMP Facility ID: 1000 0004 5989 3656
Prepared: Aug 25 11:49:47 1999Author: RMPinfo@ombwatch.org
Last modified: 6 September 2001
http://www.actionpa.org/fluoride/chemicals/rmp-hometown.html