Sterling Chemicals Incorporated - Executive Summary
Sterling Chemicals |
RISK MANAGEMENT PROGRAM PLAN
This is an up-date of a previous RMP submitted by Sterling Chemicals Inc. It has been prepared in strict accordance with the provisions outlined in 40 CFR 68.190(b)(4). The initial RMP, submitted in June 1999, has been updated because a regulated substance, above the EPA-specified threshold quantity, has been introduced into a new process at the Texas City plant.
The new process involves the manufacturer of DSIDA (disodium iminodiacetate). DSIDA is a key raw material in the manufacture of an agricultural herbicide. DSIDA is not a regulated substance per 40 CFR Part 68, the EPA's Risk Management Program. However, some of the raw materials used to manufacture DSIDA are regulated substances.
Formalin is a regulated substance and is one of the raw materials used in the manufacture of DSIDA. The appropriate hazard assessments have been performed on the design and operation of the new process and issues relevant t
o formalin are summarized herein.
Many parts of this summary have not changed since the initial RMP submittal in June of 1999. The importance of these sections to the overall risk management program at Sterling makes iteration vital in explaining our commitment to our employees, community and the environment.
Accidental Release Prevention and Emergency Response Policies
The accidental release prevention and emergency response policies at the Sterling Chemicals Inc. ("Sterling") Texas City, Texas facility ("Texas City Plant") are engrained in the fundamentals of the process safety prevention program.
In our Texas City Plant, we presently handle chemicals, which are considered hazardous by the Environmental Protection Agency (EPA). The same properties that make these chemicals valuable as commodities in the production of consumer products also make it necessary to observe specific safety precautions. These safety precautions are exercised in the handling and production processe
s to control human and environmental exposure in an effort to reduce the overall threat to our workers as well as the surrounding communities.
It is Sterling's policy to adhere to all applicable federal, state, and local laws, rules, and regulations. However, the safe handling of hazardous chemicals is paramount at Sterling and we adhere to standards and recommended practices governing the safe handling of hazardous chemicals to ensure that we have obtained a reasonable level of risk reduction. Investigation of inherently safer technologies, hazardous chemical inventory reduction and/or elimination studies, and fail safe design applications are a few of the continuous improvements occurring at Sterling. Safety depends upon our management commitment, the manner in which we handle and process chemicals, the safety devices inherent to our process designs, our operating procedures and philosophies, and the training of our workers.
We believe that accountability for safety reaches th
roughout all levels of management at Sterling. Senior management's commitment and dedication to continued safe operating practices is clearly evident in our organization structure and employee empowerment. This is no more evident than in our involvement in the OSHA Voluntary Protection Program ("VPP"). Our participation in VPP is a strong example of management's commitment to the safety of our Texas City Plant.
We have made extensive improvements to safety and health programs like process safety (prevention) management, emergency preparedness and response, work permitting, and training.
Additionally, we believe employee involvement is the cornerstone to continued safe operations. We call it employee ownership and its success is portrayed through our lower injury rates, fewer incidents, and improved operating efficiencies at the Texas City Plant. Our employees volunteer to participate in a unique program known as 'Sterling Teams to Enhance Plant Safety' (STEPS). There are cur
rently seven active STEPS teams. They are: a) Employee Health and Safety Awareness, b) Contractor Safety, c) Safety Training, d) Voluntary Protection Program (VPP) OSHA Star, e) Safety Procedure Review, f) Process Safety Management, and g) Emergency Response Improvement. The teams present summary reports of their activities and improvements to senior management each month.
The Emergency Preparedness and Response Plan outlines procedures for warned and unwarned emergencies that may occur at the plant. Warned emergencies are usually weather related, such as hurricanes, or freezes. Unwarned emergencies usually consist of on-site emergencies such as fire, explosion or a chemical release. Sterling provides the emergency response teams with state-of-the-art equipment and the latest training and procedures. This ensures prompt mitigation actions during incidents and rapid notification to any surrounding neighborhood that may be inadvertently affected by a plant emergency.
policies covering five organizations that make up the overall emergency preparedness and response program for the plant. These five emergency response organizations include: a) Sterling Fire Brigade, b) Sterling Emergency Medical Technicians, c) Sterling Emergency Wardens, d) Sterling Emergency Communications Coordinators, and e) STEPS Emergency Response Improvement Team. These organizations are capable of responding to onsite and offsite emergencies. In addition, Sterling is an active member of the Texas City Mutual Aid System.
Facility Description and Regulated Substances Handled
Sterling is a wholly owned subsidiary of Sterling Chemicals Holdings, Incorporated. Sterling is a diversified chemical company. Its petrochemical business manufactures styrene, acrylonitrile, methanol, acetic acid, plasticizers, sodium cyanide and tertiary butylamine at the Texas City Plant. Sterling's headquarters are located in Houston, Texas.
Sterling is a large domestic producer of styrene, th
e primary end products of which are building products, automotive and boat components, disposable cups and trays, packaging and containers, housewares, tires, audio and videocassettes, luggage, children's toys, paper coatings, appliance parts and carpet backing.
Sterling is also a significant global producer of acrylonitrile, the primary end products of which are apparel, furnishings, upholstery, household appliances, carpets, and plastics for automotive parts using ABS and SAN polymers.
In addition, Sterling is a large producer of acetic acid, which is used in many products, including adhesives, cigarette filters and surface coatings. Other commodity chemicals produced at Sterling include: a) methanol, used as a feedstock for the acetic acid unit. b) plasticizers, used in the production of insulation, upholstery and plastic molding; c) tertiary butylamine or TBA, used in the manufacturer of solvents, pharmaceuticals, synthetic rubber and pesticides; and d) sodium cyanide, used
in electroplating and precious metals recovery.
The Texas City Plant covers approximately 290 acres within the Texas City Industrial Complex. It has marine facilities for receiving sea-going ships and barges, rail facilities for delivery and shipment of chemicals by rail, and a network of pipelines supplying needed feedstocks. It is located at 201 Bay Street South in Texas City, Texas, Galveston County.
There are 500 Sterling employees at the Texas City Plant, which are represented by ten union labor organizations. There may be approximately 900 total workers at the plant at any one time during labor-intensive activities such as turnarounds.
We presently handle both toxic and flammable chemicals, which are considered hazardous by the EPA. These substances are present in quantities greater than the threshold quantity identified by the RMP regulation and therefore are included in our risk management program.
Ammonia (anhydrous) - Ammonia is primarily used to produce acrylo
nitrile. Ammonia is received by refrigerated barge. It is stored in a refrigerated tank at atmospheric pressure. The storage tank is contained within a concrete bunker to mitigate any failure of the storage tank. Sterling has a capacity of approximately 33,000 metric tons of ammonia.
Acrylonitrile - The acrylonitrile unit at Sterling has an annual rated production capacity of approximately 740 million pounds.
Chlorine - Chlorine is used for water treatment at Sterling. It is received by special equipped truck, designed to transport chlorine one-ton containers. Approximately 15, one-ton containers may be in use at the Texas City Plant at any one time for the purification and disinfection of water.
Hydrogen Chloride (anhydrous) - Hydrogen chloride is received into the plant by tank car (rail service) from Dow Chemical. These tank cars are temperature controlled and are constantly monitored while inside the plant to ensure that the chemical remains within safe temperatures and pres
sures. Each tank car at the Texas City Plant has a capacity of approximately 145,000 pounds. At any one time, two tank cars may be onsite at the Texas City Plant.
Hydrocyanic Acid (hydrogen cyanide) - Hydrogen cyanide is a by-product of acrylonitrile manufacturing and is used as a raw material for the production of TBA, DSIDA, sodium cyanide and is also burned as fuel. At any one time, approximately 46,000 pounds of hydrogen cyanide may be present at the Texas City Plant.
Sulfur Dioxide - Sulfur dioxide one-ton containers are used at the plant. Sulfur dioxide is used as a polymerization inhibitor for hydrogen cyanide in the acrylonitrile process and in the new DSIDA process. It's received by special equipped truck, designed to transport one-ton containers. At any one time, 5 one-ton containers of sulfur dioxide may be present onsite at the Texas City Plant.
Formalin (50% formaldehyde in water) - Formalin is received into the plant by tank car (rail service). It is used in the ma
nufacture of DSIDA. Assuming a full storage tank and delivery of two tank cars, the maximum inventory of formaldehyde that may be onsite at any one time would be approximately 503,000 lbs.
Flammable Substances (propane/propylene/natural gas) - Propylene is used to produce acrylonitrile. It is reacted with ammonia over a solid-fluidized catalyst at low pressure with ammonia to produce acrylonitrile. Propylene and other flammable materials are supplied to the plant by pipeline.
Offsite Consequence Analysis (worst-case & alternate-cases)
The RMP rule requirements for identification and selection of a worst-case hazard scenario are prescriptive and ignore most safety systems designed to mitigate an incidental release. Based on EPA defined Offsite Consequence Analysis (OCA) parameters, Sterling has one worst-case hazard scenario for the toxic materials handled onsite and one for the flammables handled. The worst-case is a scenario resulting from an accidental release that is estimat
ed to create the greatest distance in any direction to an EPA defined concentration (endpoint).
Sterling's worst-case toxic scenario involves anhydrous hydrogen chloride (HCl). Hydrogen chloride is received via tank car (rail service) into the plant from Dow Chemical. These tank cars are insulated. Each car may have a maximum of 145,000 pounds of liquid HCl at any one time. A maximum of two tank cars may be present in the Texas City Plant. This results in a maximum inventory of 290,000 pounds at any one time. The worst-case assessment for HCl used the EPA's theoretical assumption that the tank cars catastrophically fail and release their entire contents within 10 minutes. This scenario completely ignores any passive mitigation.
Using the EPA's Offsite Consequence Analysis Guide Document to calculate the greatest downwind distance, it was determined that a hydrogen chloride vapor cloud may extend 16 miles from the plant.
The worst-case flammable scenario involves the instanta
neous failure of a propylene storage vessel and subsequent failure of all active safety systems. The scenario assumes that the total contents of the propylene storage vessel (130,100 pounds) detonates and results in a destructive blast wave. The assessment calculated a blast extending out to 1 psi. The 1 psi damage plot would extend a maximum distance of 0.43 miles from the propylene storage vessel.
The EPA rule also prescribes that alternate or more likely accident scenarios involving regulated chemicals are identified. Each of the regulated chemicals was assessed, using prescriptive EPA scenarios and risk assessment guidelines. The analysis of the alternate scenarios included mitigation affects from both passive and active safety systems.
The results of the alternate scenario analysis are as follows:
1. The inadvertent failure of the 6" barge transfer hose during offloading of ammonia into the ammonia storage tank was selected as the alternate case for ammonia. This fai
lure assumes that the hose suddenly uncouples and releases 12,967 pounds of ammonia. Evaporation of the liquid ammonia could result in the formation of a vapor cloud extending 0.7 miles from the spill site.
2. The accidental overfilling of the acrylonitrile storage tank 51T18-1. Acrylonitrile spills from overflow line into concrete containment area. Typical fill rate for the tank is 1,316 lbs/min and this scenario assumes it takes 10 minutes to detect the spill and mitigate it. Evaporation of the acrylonitrile in the containment dike could result in the formation of a vapor cloud of acrylonitrile extending 0.53 miles from the spill.
3. A chlorine leak at a valve connection on a 1.0-inch pipeline that results in a complete separation of the pipeline at the valve. The release is detected and controlled within 15 minutes. A calculated 1,256 pounds/minute was released during the scenario. Dispersion of the chlorine gas in the atmosphere could result in a vapor cloud of chlorine ext
ending 0.54 miles from the release point.
4. A hydrocyanic acid (hydrogen cyanide) leak occurs when a 1/8-inch valve connection shears off of a 3.0-inch pump discharge line. The release is detected and controlled within 10 minutes. Approximately 262 pounds/minute was released during the scenario. Dispersion of the gas in the atmosphere could result in a vapor cloud of hydrogen chloride extending 0.81 miles from the release point.
5. Hydrogen chloride is released at a 1.0-inch filter drain line. The release is detected and controlled within 10 minutes. A calculated 102 pounds/minute was released during the scenario. Dispersion of the gas in the atmosphere could result in a vapor cloud of hydrogen chloride extending 0.56 miles from the release point.
6. Sulfur dioxide leak occurs when a 1.0-inch line fails and results in a complete separation from the sulfur dioxide container. The release is detected and controlled within 10 minutes. Approximately 1,616 pounds/minute was relea
sed during the scenario. Dispersion of the sulfur dioxide gas in the atmosphere could result in a vapor cloud of sulfur dioxide extending 0.65 miles from the release point.
7. Formalin release occurs when a 3.0-inch Tank Car Unloading Pump seal fails during unloading operations. The release is detected and controlled within 20 minutes. Approximately 178 pounds/minute was released during the scenario. Vaporization of the formaldehyde in the formalin-water solution could result in a toxic cloud extending 0.80 miles from the release point.
8. A motorized construction vehicle inadvertently strikes a 2.0-inch flammable pipeline and completely separates the line. Plant emergency responders control the flow of flammable gas within 10 minutes. Inadvertent ignition of the flammable gas cloud results in an overpressure that could extend up to 0.18 miles from the ignition source.
Accidental Release Program & Chemical-Specific Prevention Steps
Sterling continues to manage changes to i
ts process chemicals, technology, equipment and procedures for processes covered by OSHA's Process Safety Management ("PSM") program and EPA's Risk Management Program. Sterling's "Management of Change" Safety & Health Procedure (SP-0101) has been a useful tool in helping employees understand how to apply Management of Change ("MOC") to prevent or minimize the potential consequences associated with a catastrophic release of toxic, reactive, flammable, or explosive chemicals at Sterling.
A core group of Sterling employees serve as Management of Change "Coordinators" for the manufacturing departments and Materials Handling department. In addition to determining MOC notification needs, the MOC Coordinators are responsible for maintaining department MOC logs and records, and ensuring that necessary changes are made to department procedures and process safety information.
Depending on the nature of the change, Sterling identifies three levels of MOC technical / safety reviews. Level 1
and 2 MOC reviews require the use of a "Safety/Health/Environmental Checklist" to discuss potential hazards associated with the change and are documented on the MOC Form. A Level 3 MOC review requires that in addition to the use of a "Safety/Health/Environmental Checklist," a Process Hazard Analysis be conducted on the change (unless waived by Safety & Health Department), and that a representative from the Safety & Health Department participate. The facilitator of each PHA must be qualified to do so per Sterling Safety Procedure SP-0131.
Pre-Startup Safety Reviews ("PSSRs") are performed for new facilities and for modified facilities when the modification is significant enough to require a change in the process safety information, and the facilities are a part of a PSM or RMP covered process. These PSSRs are held to verify that all appropriate safety information has been updated and that all appropriate reviews are performed and training has been completed.
Sterling completed 1
00% of its baseline PHAs by the May 26, 1997 deadline imposed by OSHA. The 1,345 recommendations generated during these reviews were prioritized using Sterling's Risk Ranking Matrix. The Manufacturing Team Leaders were responsible for communicating the PHA recommendations to all affected employees, and the Safety & Health Department entered the recommendations into Sterling's PHA Recommendation Tracking database. Monthly progress reports are sent to management based on updates received from the departments responsible for addressing the recommendations. Of the original recommendations only five (5) remain unresolved.
Sterling began revalidating its PHAs in October 1997 and has completed twenty-seven (27) revalidations. Revalidation efforts resulted in the identification of 171 additional recommendations. The 171 recommendations from these PHAs have been entered into a tracking database and are the subject of monthly status reports.
Five year Accident History
Since the initial
RMP submittal in June 1999, there has been no accidental release of EPA regulated chemicals in accordance with RMP reporting requirements outlined in 40 CFR Part 68.42.
Emergency Response Program
A number of improvements have been made in the emergency response organizations. A few of these improvements include the development of the Emergency Procedure Plan ("EPP") and the Fire/Spill Strategic Response Plan, formation of the Emergency Communication Coordinators ("ECC"), and formation of the STEPS Emergency Response Improvement Team.
In order to improve emergency response efforts within the plant, Sterling formed the ECC group of volunteers. The function of this group is to provide: offsite industrial hygiene monitoring during a chemical release incident, perform dispersion modeling in the event of a release, and act as a communications resource to make notifications and provide pertinent information during an incident.
The ECC group conducts training on their required duties
twice a month. Training items include the use of industrial hygiene monitoring equipment, radio communication equipment, and the CHARM dispersion modeling system. The ECC group has made good progress towards fulfilling their role in the emergency response program at Sterling. This group plans to continue training on their respective duties in order to improve their response efforts. Incident command training and further dispersion modeling training is planned for the future.
The Emergency Response Improvement Team ("ERIT") was formed to coordinate emergency response activities at the plant. The team looks at each part of emergency response and determines if improvements are needed in areas of training, communications, etc.
One of the biggest contributions of the ERIT is the coordination of semi-annual emergency procedure plan drills. These simulated drills include scenarios of spills or releases that are responded to by emergency response teams. Every aspect of the drill is
critiqued and reviewed to determine improvements that need to be made in each area of emergency response. All recommendations arising from the critique are tracked until resolved by the ERIT.
Planned Improvements to Reduce Risk
In accordance with its risk management program, Sterling Chemicals has conducted continuous self-examination evaluations designed to identify and assess process/operational risk employees and the community. One of the primary aspects of Sterling's risk management program is the empowerment of each business unit with the responsibility for continuous safe operations.
As an environmentally responsible company, Sterling has implemented a plant-wide risk management program designed to identify risk and assess viable alternatives. Identified alternatives or substitutions must meet the company's health, safety, and environmental standards. In addition, any change to a new process or technology must be thoroughly analyzed to ensure that inherent hazards a
re not inadvertently introduced.
Through Sterling's active pursuit of inherently safer operations, alternative methods were identified that enhanced safety and were financially feasible. This has led to a reduction of 14,000 pounds of chlorine and 71,000 pounds of sulfur dioxide at the plant site. One-ton chlorine containers at three separate locations within the plant complex were replaced with safer bleach processes. The substitution of a different catalyst also led to the elimination of a sulfur dioxide storage tank.