Witco Corporation Houston Texas Plant - Executive Summary
Witco Corporation |
RISK MANAGEMENT PLAN - EXECUTIVE SUMMARY
Witco Corporation is committed to operating in a manner that is safe for our employees, contractors, the public and the environment. As part of this commitment, Witco Corporation has established a system to help ensure the safe operation of chemical processes at this facility. One part of this system is a risk management program (RMP) that is required by the USEPA's Accidental Release Prevention Requirements (RMP Rule) in Title 40 of the Code of Federal Regulations Part 68. One of the requirements of the RMP Rule is to submit a Risk Management Plan (RM Plan), which describes the risk management programs at the facility for review by the USEPA and the public.
2. Accidental Release Prevention and Emergency Response Policies
Witco Corporation is committed to the safety of its employees, contractors, the public and the environment through the prevention of accidental releases of hazardous sub
stances. In the event of a significant accidental release, our personnel will respond to control and contain the releases. In most foreseeable circumstances releases could be controlled by shutting down operations and/or by applying generous quantities of water to absorb and dilute the release since all of our regulated chemicals are water soluble. If necessary, Witco will evacuate onsite personnel and contact the local emergency planning committee (LEPC), fire department and police to help handle the emergency and to help warn the public.
3. Facility Description and Regulated Substance Handled
The Houston Plant stores regulated substance for use in several chemical processes. In each process the regulated substances are chemically transformed into less hazardous products. The oxylation and neutralization processes make products used as ingredients in soaps for laundry and personal care, and additives used in the agricultural and petroleum industries. The sulfur dioxide is used as
a raw material to make an ingredient in a glass cleaning formulation.
The following is a list of the regulated chemicals handled in each process and the largest amount of each chemical stored in a single container:
Process Regulated Substances Largest Container
Oxylation Ethylene Oxide 35,000 gallons
Propylene Oxide 35,000 gallons
Neutralization Isopropyl Amine 5200 gallons
Aqueous Ammonia 6300 gallons
Sulfur dioxide Sulfur Dioxide 200 gallons
4. Offsite Consequence Analysis
Witco performed an offsite consequence analysis (OCA) to estimate the potential for an accidental release of a regulated substance to affect the public or the environment. The OCA consists of evaluating both the worst case release scenario and an alternative release scenario for releases of toxic and flammable substances. The worst case scenario is not expected to occur over the life of the facility. An alternative release scenario represents a release that might be a r
easonable scenario to consider for emergency planning purposes.
The main objective of performing the OCA is to determine the distance at which certain effects might occur to the public because of an accidental release. This distance is called the endpoint distance. Knowledge of the end point distance is useful for emergency planning purposes and for helping to make appropriate accident prevention decisions.
When considering the release of a toxic substance, most people at the endpoint distance would be able to walk away from the exposure without any long-term health consequences, although some short-term consequences are likely. Some people who are particularly susceptible could be incapacitated.
When considering explosion of a flammable substance, people at the endpoint distance are likely to be knocked down by the blast and windows could shatter. Potential for structural damage to buildings exists, although a building collapse is unlikely.
When considering the fire hazard of
a flammable substance people at the endpoint distance are likely to receive second degree burns over the exposed parts of their bodies if they cannot quickly find cover.
4.1 Worst Case Toxic Release Scenario
The worst case release scenario for regulated toxic substances is the release of the entire contents from a 35,000 gallon ethylene oxide tank in 10 minutes, which is the worst case scenario defined by the USEPA. The maximum distance to the toxic endpoint concentration is approximately 12 miles. The population within a 12 mile radius of the plant is approximately 800,000 people.
The USEPAs models were used to determine the distance to the toxic endpoint.
4.2 Alternative Toxic Release Scenarios
The alternative release scenarios for all of the toxic substances were assumed to be leaks with no steps taken to mitigate the release. Water sprays onto leaks should be highly effective in knocking down vapors to reduce the impact of the leak since all of the regulated chemicals are wa
For ethylene oxide the distance to the toxic endpoint would be 0.4 miles. There are approximately 10 residences and some industrial and commercial neighbors within a 0.4 mile radius.
For propylene oxide the distance to the toxic endpoint would be 0.2 miles. There are approximately 3 residences and some industrial and commercial neighbors within the 0.2 mile radius.
For aqueous ammonia the distance to the toxic endpoint would be 0.2 miles. There are approximately 3 residences and some industrial and commercial neighbors within a 0.2 mile radius.
For sulfur dioxide the distance to the toxic endpoint would be 0.4 miles. There are approximately 10 residences and some industrial and commercial neighbors within a 0.4 mile radius.
4.3 Worst Case Flammable Release Scenario
The worst case scenario for a regulated flammable substance is the based on the assumption that the total quantity of the liquid in a 5200 gallon isopropylamine tank is released, vaporizes and then deton
ates. The end point distance for the worst case explosion scenario would be 0.2 miles. There are approximately 3 residences and some industrial and commercial neighbors within a 0.2 mile radius.
4.4 Alternative Flammable Release Scenario
For the alternative flammable release scenario, it was assumed that a 10,000 pound vapor cloud detonated (about 1/3 of the tank volume). This scenario is not much more likely than the worst case scenario for isopropylamine and the end point distance would be the same as the worst case release scenario.
Ethylene oxide and propylene oxide are flammable in addition to being toxic and Witco is taking precautions to manage the fire and explosion risks of these substances as well as the toxicity hazards.
5. General Accidental Release Prevention Program and Chemical Specific Prevention Steps
The following is a summary of the general accident prevention program in place at Witco Houston Plant:
5.1 Employee participation
Witco encourages and insists u
pon employee participation in process safety management. Knowledgeable operators write operating procedures, review new or modified product recipes, and are included in process hazard analyses. Employees attend safety meetings, which are held about 6 times per month to provide ample opportunities for employees to attend. All meetings throughout the company (other than safety meetings) must begin with a safety topic to increase safety awareness and employee involvement. Several operators have been pulled off of regular duties for extended periods to review and comment on new designs and to help train themselves and others on major process changes before implementation.
5.2 Process Safety Information
The Plant maintains extensive information on its chemical hazards, processes, procedures and equipment, which is used by employees as needed to help them do their jobs safely.
5.3 Process Hazard Analysis
New and existing processes are examined using formalized methods of hazard analy
sis. These methods are designed to help knowledgeable employees recognize process hazards. Recommended actions are tracked until resolution.
5.4 Operating Procedures
The Houston Plant maintains written procedures that address various modes of operation for the regulated processes, including normal operations as well as emergency and abnormal operations. Operating procedure are available from document control department and control rooms where operators work.
Safety training is conducted 6 times per month and the topics change each month. Process safety topics are covered during several months of the year. The safety topics are posted on a safety calendar, which is available to employees. Initial training is provided to new employees. Experienced operators train new employees on the proper operating procedures until they believe from direct observation that the newer employee is ready to run the process. Refresher training is conducted periodically.
The Houston Plant uses contractors to supplement its work force during periods of increased construction or maintenance activities. Contractor's safety performance is reviewed before hiring the contractors. Contractors are given safety training prior to being allowed to work in the plant to help assure that our safety procedures are followed. A permit system is in place, which requires contractors to obtain written approval in the form of a work permit from knowledgeable Plant personnel before work by a contractor commences on a regulated process. Contractors are informed of the process hazards before written approval to commence work is given.
5.7 Pre-startup safety review (PSSR)
The facility conducts a PSSR before any new or modified process is operated to make sure that the new or modified facilities and the associated procedures are safe to use for operation.
5.8 Mechanical Integrity
The facility has an ongoing system to maintain the process equipment in good working orde
r as needed for safe operation. The facility has procedures in place for the testing and inspection of equipment and makes sure that equipment is operated within the safe operating limits. New equipment and installations are inspected before they are operated to make sure they were constructed properly and are safe to operate. Equipment containing regulated toxic or regulated flammable substances are given the highest priority in the mechanical integrity system.
5.9 Safe Work Practices
The facility has permit systems in place to make sure that hazardous activities such as hot work, entering vessels and confined spaces, and opening pipelines are performed safely by requiring that knowledgeable persons from operations and maintenance provide written permission before such work can be performed.
5.10 Management of Change
The facility has procedures in place to manage changes to procedures and equipment safely. Operations and engineering management personnel assure that changes are n
ot authorized until it is safe to do so and the necessary safety requirements are met.
5.11 Incident Investigation
The facility has procedures in place that require the reporting and investigation of incidents that result in or could reasonably resulted in a fire explosion or toxic release. Any urgent recommendations resulting from the incident investigation are addressed promptly and other recommendations are tracked until they are resolved. A file is maintained to record the incident history for review and for consideration in the next process hazard analysis.
Audits are conducted every 3 years by the Corporate Safety and Health Department and reports are written to which the facility must respond. The status of recommendations is tracked until resolution.
6. Chemical Specific Prevention Steps
The hazards of the processes operated at the facility are managed safely with the help of the programs previously described. The following is a description of chemical spec
ific accident prevention steps:
6.1 Ethylene Oxide and Propylene Oxide
Witco Corporation has had a special safety committee for oxylation safety since the 1970s. This committee has met periodically to discuss ways to improve oxylation safety. Members from several operating plants and corporate safety personnel participate in the committee meetings. Four members or former members of the oxylation safety committee are currently located at the facility and are available for advice on safety issues. Recommendations from committee members have resulted in numerous improvements in the design of systems for safe operation of the existing units and especially in the design of replacement units now under construction at the Witco Houston Plant.
The ethylene oxide and propylene oxide suppliers have well developed product stewardship programs and periodically visit the site to provide assistance in the safe handling of oxides and special training materials are provided.
Process controls no
w in place include numerous sensors, alarms and interlocks to detect and prevent hazardous upset conditions. Automatic shut off valves prevent the oxide from being added unless the process conditions are safe. Leak sensors provide alarms if leaks are detected and deluge systems are provided for tank, unloading and reactor areas to absorb leaks. Dikes are provided for the storage tanks. All of the vessels are protected with self closing relief valves and all of the vessels are maintained under an inert atmosphere.
6.2 Isopropylamine and Ammonia
The isopropylamine and aqueous ammonia are stored at ambient temperatures under nitrogen blankets. The tanks are located in a diked area with a nearby drain to a large wastewater basin. Any spilled material would not tend to accumulate underneath the tanks, but would tend to flow to and be diluted in the wastewater basin. A firewater monitor nozzle is located nearby for use in fighting fires or diluting leaks to reduce the chance of a fir
e or to greatly lessen the impact of a toxic release. A scrubber is provided to absorb vapors from normal venting or emergency relief.
6.3 Sulfur dioxide storage
The sulfur dioxide is stored in thick walled steel containers to resist breakage from mishandling. Each container holds about 200 gallons, which is less than the threshold quantity of sulfur dioxide. The cylinder storage area is protected from traffic by a wall and steel barriers. The cylinders are not stored near other tanks or containers. The plant has repair kits to help stop leaks and leakage could be absorbed with firewater.
7. Five Year Accident History
The Witco Houston Plant has not had any releases that have resulted in deaths, injuries or significant property damage on site or known offsite injuries, evacuations or sheltering in place or environmental damage.
8. Emergency Response Program
The facility has a written emergency response plan. The emergency response plan was issued to the Fort Bend LEPC. The p
lant periodically conducts drills to train personnel and to test the plan.
9. Planned Changes to Improve Safety
Construction of facilities to replace over most of the existing oxylation equipment is nearly complete. The new facilities are remotely located away from employees and the public and the new designs incorporate Witco's latest safety technology for process control, emergency shutdown systems, leak detection, emergency response, deluge systems, emergency cooling vents, vent scrubbing systems, and spill containment to contain both spilled material and emergency water.