Borcks Country Home Bakeries, Inc. - Executive Summary |
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COUNTRY HOME BAKERS EXECTUTIVE SUMMARY THE ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES In this facility, we use Anhydrous Ammonia, which is considered hazardous by the EPA. This chemical must be used to provide cooling for the process and cooling for the areas. It is our policy to have programs in place dealing with safety precautions in handling these substances and to prevent unnecessary human exposure, to reduce the threat to our own personal health as well as our co-workers, and to reduce the threat to nearby members of the community. It is our policy to adhere to all applicable Federal and state rules and regulations. Safety depends upon the manner in which we handle ammonia combined with the safety devices inherent in the design of this facility combined with the safe handling procedures that we use and the training of our personnel. SOURCES AND PROCESS DESCRIPTION The Country Home Bakers manufacturing facility is in the business of producing breads, ro lls, dough, and cookies for sales to the public. These products are cooled by evaporators and heat exchangers during the process. Anhydrous Ammonia is the refrigerant used for cooling due to the low cost of the medium and the low temperatures that must be obtained. The ammonia is enclosed within a closed loop that removes heat from the products and storage rooms. Ammonia is vaporized in evaporator coils by heat removed from the products and cooling of the areas at low temperatures and pressures and then the heat is dispensed from the system to the atmosphere by moving outside air and water over condenser coils. The ammonia system at the Country Home Bakers contains 36,000 pounds of ammonia. SUMMARY OF MAJOR HAZARDS CONSEQUENCES OF FAILURE TO CONTROL HAZARDS HEALTH HAZARDS Ammonia is a colorless gas with extremely pungent odor. Liquid ammonia vaporizes to a poisonous gas cloud. Ammonia is a severe irritant of the eyes. It penetrates the eyes more readily than any other alkal i. Contact with liquid anhydrous ammonia and concentrated solutions can produce severe eye injury or blindness. Exposure of the eyes to high gas concentrations can cause temporary blindness and severe eye damage. Laceration or watering of the eyes can occur upon exposure to 150 ppm ammonia gas and higher. Ammonia is an irritant by inhalation. At increasing concentrations it can cause symptoms ranging from runny nose, coughing, chest pain, trouble with breathing, and death. It can cause severe breathing difficulties that are delayed in onset. Inhalation of concentrations of 2500 to 6500 ppm causes shortness of breath, bronchospasm, chest pain, and pulmonary edema (filling of the lungs with fluid) that may be fatal. Exposure of the skin to liquid anhydrous ammonia or high concentrations of the gas can cause first and second degree burns of the skin. Vapor concentrations of 10,000 ppm are mildly irritating to moist skin, while 30,000 ppm or greater causes a stinging sensation and can produce skin burns and blisters. These high concentrations of ammonia are corrosive to moist skin and other moist body tissues. Physical Hazards Ammonia or ammonia with oil or other debris is an explosion hazard when exposed to flame or fire. The Lower Explosive Limit (LEL) is 16% and Upper Explosive Limit (UEL) is 25% by volume in air. Elevated temperatures can cause containers of the substance to explode. Ammonia emits toxic fumes when exposed to heat. When heated to temperatures above 8500F, ammonia will emit hydrogen gas. The auto ignition temperature is 12040F if catalyzed by iron. Ammonia can react to form potential violent or explosive reactions with halogens (e.g., chlorine, bromine). It can react to form potential violent or explosive reactions with strong oxidizers, hypochlorite bleaches, silver compounds, mercury compounds, gold, other metals, and acids. Common Exposure Control Methods o Process enclosure o Local exhaust ventilation o General dilution ventil ation o Personal protective equipment o Use of water o Area monitoring (with alarm systems) POTENTIAL FOR EXPOSURE TO AMMONIA The refrigeration operation is a closed system with no purposeful exposure to ammonia. As a closed system, exposure potentials are primarily related to equipment failure, fugitive emissions from improperly adjusted or worn valve packing, failure of pump and compressor seals and pipe connector gaskets, or mistakes in operation of the system. WORST CASE SCENARIO The worst case scenario for the Country Home Bakers is the release of 23,990 pounds of ammonia from the system's largest vessel, the -450 F liquid recirculator , in a 10 minute period. The toxic endpoint was determined by using the Aloha modeling programs. With a wind speed of 1.5 m/sec and a Stability Class of F in an urban topography the endpoint of the spill was determined to be 2.0 miles from the receiver. The plant site is located in the city of Atlanta, Georgia. The public receptors within a radius of 2.0 miles from the plant site are schools, residents, hospitals, public parks and downtown office buildings with a population of 55,569. In case of a major leak, passive mitigation's in place are drains that go to a collection tank for the ammonia area. ALTERNATE CASE SCENARIO Alternate case scenarios for the Country Home Bakers were reviewed by the maintenance and operating sections. Considerations were given to the most probable cause of leaks within the system. The possible leak scenarios considered were: o Transfer hose rupture o Process piping failure o Process vessel or pump releases from seals, drains, bleeds o Rupture of a sightglass o Overpressure and release through relief valves After discussing these and the operations of the refrigeration system, it was decided that the failure of mechanical seal was the most probable cause of a leak within the system. Calculations were made considering the leakage of low pressure ammonia liquid from the -26 Recircul ator Pump seal. The seal failure would create a 1" long by 1/4" wide opening in the seal. At the system pressures, it was determined that a release rate of 56 lbs/min would be released for 60 minutes if this incident occurred. Wind speeds of 3.0 m/sec and a stability class of D were used. The toxic endpoint was determined to be 0.2 miles by using the Aloha computer modeling programs. This was based on releasing 3,100 pounds of liquid ammonia. The public receptors in this area would only include area residents. The population of this area would be 450. There were no active or passive mitigation credits for this scenario. THE FIVE YEAR HISTORY Country Home Bakers has had one incident that resulted in a leak of ammonia in the last five years. It was caused by ammonia leaking by a check valve in the system and causing a system overpresslure that opened a relief valve. The relief valve opened at a pressure lower than the set point. As a result of this incident, maintenance pra ctices were revised to check check valves and all relief valves that were not new were replaced. EXPLANTATION OF HOW RELEASES ARE PREVENTED Historically, exposures to ammonia most often occur from: o Leaking valve stem packing glands while opening or closing a valve o Leaking at valve flanges or other piping connections o Pressurizing any equipment with sight glasses o Mistakenly venting gas through open equipment to the atmosphere o Malfunctioning pressure relief valves o Mechanical seal failures on compressors and pumps MANAGEMENT SYSTEM RELEASE PREVENTION PROGRAM AND PREVENTION STEPS The Country Home Bakers complies with the EPA's Accidental Release Preventative Rule with all applicable state codes and regulations for ammonia. Management systems are in place to administer the RMP prevention programs for ammonia. The Plant Engineer is the responsible person for leading this program. The Country Home Bakers is in compliance with OSHA's PSM rule for ammonia. The RMP's accide ntal release preventative program for ammonia is covered by the elements of the PSM program. Controls for the preventative programs are acquired by: o Effective preventative maintenance programs o Reviews for proper design o Development of and following operating procedures o A mechanical integrity program that includes equipment testing procedures o Training to be aware of potential exposure situations and using exposure prevention procedures and/or protective equipment. PLANNED CHANGES TO IMPORVE SAFETY Country Home Bakers is putting together a training program to enhance the skills of the refrigeration operators and to increase their abilities to respond to emergencies. This includes offsite refrigeration training courses, operating procedure reviews and drills. Country Home Bakers also arranged for combined training with the local fire department on their emergency response plan. EMERGENCY RESPONSE PLAN This facilities emergency response program is based on the IIAR's "Risk Management Guidelines Program for Ammonia Refrigeration." An emergency response plan is in place at the Country Home Bakers to deal with incidents and emergencies that might take place on site. The site maintains it's own HAZMAT teams. Training for these functions is given annually per state requirements. Onsite drills are also scheduled as part of the emergency response plan to familiarize employees of the dangers of ammonia and the proper response to alarms and evacuations. The plan has been provided and reviewed with the Fulton County Local Emergency Planner Center. Coordination with the LEPC has been made to notify them through the emergency response plan to respond to incidents that may affect the public. |