Trenton Home Foods - Executive Summary
EXECUTIVE SUMMARY |
1.0 Release Prevention and Emergency Response Policies
The Trenton Home Foods facility in Trenton, Missouri has a good record in preventing releases of anhydrous* ammonia. The Trenton Home Foods facility has a thorough emergency training program for on-site emergency responders. The facility has implemented Trenton Home Foods Emergency Action Plan (emergency response program) which is a plan designed for the safety of its employees', the community and the environment. This detailed emergency response program includes procedures for handling an emergency - the established action plan and appropriate personnel involved in containing a hazardous release (HAZMAT team). As part of this emergency response program, Trenton Home Foods emphasizes a thorough training program. With the potential dangers associated with a hazardous chemical release, Trenton Home Foods has researched and developed safe containment and disposal procedures. All of these components make the T
renton Home Foods HAZWOPER plan a thorough and comprehensive plan for release prevention and emergency response.
The emergency response policies at the Trenton Home Foods facility ensure that there is emergency response coverage 24 hours - 7 days per week. There are also provisions for coordination with outside agencies such as the Trenton Fire Department and Grundy County LEPC in the event of an emergency.
*From this point in the Executive Summary, anhydrous ammonia will be synonymous with ammonia.
2.0 Process Description and Regulated Substances
Trenton Home Foods is a meat and cheese canning, thermal processing facility, with Vienna sausage as the main product. The NAICS code for this process at this facility is 311612. Many areas of the plant are refrigerated to preserve the food products.
Trenton Home Foods has one regulated substance under 40 CFR 68: ammonia. Ammonia is used as a refrigerant in the refrigeration of the foods in the various areas of the plant.
ia threshold for triggering applicability to 40 CFR 68 is 10,000 pounds. The Trenton plant has one ammonia refrigeration process for the preservation of the food products. The quantity of ammonia stored on-site is approximately 16,000 pounds. The process does exceeds the threshold quantity of 10,000 pounds as set by 40 CFR 68 and thus is regulated.
3.0 Worst-case and Alternative Release Scenarios
The ammonia refrigeration system has associated hazards that can potentially affect on-site employees and the general public off-site if there is a release from the system. Described below are the associated hazards and the worst-case and alternative release scenarios for the regulated chemical. Though there are other scenarios possible, EPA only requires that one worst-case and one alternative scenario be reported for each regulated chemical.
Ammonia is classified as a Group 2 Refrigerant per ASHRAE Standard 34-1989. The dominant characteristic of this chemical is its
toxicity. It is a self-alarming chemical by its distinctive pungent odor. Due to this odor, persons exposed to ammonia vapor will not voluntarily stay in areas of even small concentrations. Ammonia will burn at a very narrow and high range of concentrations accompanied with a high ignition temperature. Although ammonia is not poisonous, it is corrosive to human tissue. Ammonia is readily absorbed into the moisture of the skin and, at high concentrations, can cause severe burns.
The risks to persons in an accidental release of ammonia include:
1. Corrosive attack of skin and other tissue (including lung tissue)
2. Freezing of skin and other body tissue when contacted by liquid ammonia
Below is a description of the scenarios for ammonia and their off-site consequences:
Worst-Case Scenario Description
40 CFR 68 requires that a single worst-case release be developed for a facility regardless of how many processes are present. Thus, one worst-case scenario has been developed fo
r the Trenton plant. The largest potential release of ammonia would occur with a rupture in the liquid portion of the high pressure receiver. Taking the specific definition of the worst-case from 40 CFR 68.25, the largest quantity of ammonia that can be stored in a vessel is in the high pressure receiver during a pumpout condition. The total quantity of ammonia that can be stored in the high pressure receiver is 10,394 pounds without administrative controls. It is assumed that the entire 10,394 pounds is released into the engine room.
Passive mitigation controls may be applicable to this scenario. Specifically, the high pressure receiver is located in the engine room but very close to a door with screens at the base. The building including a door might not be able to withstand an explosion if one were to occur. Therefore, passive mitigation would not be applicable to this scenario. The release rate to the outside is 1,039 lb./min. In 10 minutes, 10,394 lbs. of ammonia will be
released. Regardless of the actual release height, the worst-case release must be modeled as if it is released at ground level.
Under Section 68.25(c)(1), a regulated toxic substance such as ammonia that is normally a gas at ambient temperature and handled as a liquid under pressure shall be considered to be released as a gas over a 10 minute period. Thus, ammonia's physical state in the worst-case scenario is a gas.
Table 4-4 of the Risk Management Program Guidance for Ammonia Refrigeration was used to obtain the distance to endpoint which is 1.20 miles. Urban dispersion coefficients were used as well as a wind speed of 1.5 m/s and an atmospheric stability class of F.
The estimated affected residential population is 3,357 people. The types of affected receptors are listed in the Data Elements section.
Alternative Release Scenario Description
The alternative release scenario that meets both selection criteria was the release of ammonia from a relief valve located on the h
igh pressure receiver. Administrative and passive controls are not applicable to this scenario. Active mitigation of the release is human intervention (system shutdown at 10 minutes from the start of the release).
Our calculations showed that the ammonia vapor release rate is 57.7 lb/min.
Table 4-5 of the Risk Management Program Guidance for Ammonia Refrigeration was used to obtain the distance to endpoint which is 0.10 miles. Urban dispersion coefficients were used as well as a wind speed of 3.0 m/s and an atmospheric stability class of D.
The estimated affected residential population is 33 people. The types of affected receptors are listed in the Data Elements section.
4.0 General Accidental Release Prevention Program and Chemical-Specific Prevention Steps
Trenton Foods has developed an OSHA PSM program for their ammonia refrigeration systems. At Trenton Foods, ammonia falls under the RMP Program 3 prevention program which is identical to the OSHA PSM program. E
PA has said that if the process is in compliance with OSHA PSM, then it is in compliance with RMP Program 3. Thus, Trenton Foods' ammonia PSM has been reviewed and determined to be complete for the RMP document.
There are several aspects of the ammonia prevention program that are key:
1. The ammonia PSM program at Trenton Foods includes provisions for employee involvement, procedures for working with contractors, pre-startup safety reviews and managing change within the system. The different sections of the PSM document detail employee participation (hazard analysis team), process safety information, process hazard analysis (PHA - what-if/checklist), operating procedures, training, mechanical integrity, hot work permits, management of change, incident investigation, compliance audits and emergency planning and response (Emergency Action Plan). The plant, therefore, maintains good training, certification, and employee awareness of operating procedures.
2. Trenton Foods has establi
shed a hazards analysis team (comprising of plant employees) responsible for updating existing operating procedures for the refrigeration system and also verifying and documenting the mechanical integrity of the system.
3. In the event of a catastrophic release or an incident which could have results in a catastrophe, investigations will be undertaken (this is a policy of the PSM document). Necessary preventative measures will be taken to reduce the risk of incident reoccurence.
5.0 Five-year Accident History
The review of Trenton Home Foods' accident history includes the following range of dates: June 22, 1994 - June 21, 1999. According to 40 CFR Part 68.42(a), there have been no accidental releases at this facility.
6.0 Emergency Response Program
As mentioned previously, the Trenton Home Foods facility has developed an OSHA hazardous substance emergency response program called Emergency Action Plan. The Emergency Action Plan document contain detailed procedures for: 1) pre-emer
gency planning and coordination; 2) personnel roles and lines of authority; 3) communication; 4) emergency recognition and prevention; 5) safe distances and places of refuge; 6) site security and control; 7) emergency alerting and response; and 8) emergency medical treatment and first aid.
Trenton Home Foods' emergency response plan (Emergency Action Plan) is a detailed document which discusses the role of employees and management in an emergency situation. All emergency response personnel undergo training and records of this training are maintained and updated on site. The plan outlines specific procedures for evacuations, incident alarms and alerting. Depending upon a given situation, the Fire Department will be called to provide back-up emergency responders and equipment. The Fire Department will be called for all fire related emergencies. The incident commander has ultimate control of implementation of the emergency response plan.
7.0 Planned Changes to Improve Safety
plant has a safe ammonia system and they continue to make it even safer with improvements such as: ammonia sensors in the engine room which will be tied to the ventilation system.