Toshiba Display Devices, Inc. - Executive Summary |
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Executive Summary USEPA's Risk Management Program (RMP) rule (40 CFR 68), published in the Federal Register on June 20, 1996, was developed to assist facilities in preventing accidental releases of highly toxic or flammable chemicals. The RMP applies to an owner or operator of a stationary source that has more than a threshold quantity of a regulated substance in a process, as determined under '68.115. The USEPA has established three tiers of requirements to reduce the level of effort for facilities with a lower risk of off-site impacts. These tiers are known as Programs 1, 2, and 3. Program 1 applies to any process that has not had an accidental release with off-site consequences for the past five years, and has no public receptors impacted by a worst-case release as predicted by an off-site consequences analysis (which is required under the statute). Program 3 applies to processes in specified industries, and to all processes subject to the OSHA Process Safety Managemen t (PSM) standard, unless the process is eligible for Program 1. Program 2 applies to processes not covered by Programs 1 or 3. The Toshiba Display Devices, Inc. (TDD) facility uses more than the threshold quantity of aqueous hydrofluoric acid (1,000 pounds) at a concentration exceeding 50% by weight. TDD is therefore required to submit a Risk Management Plan (RMP) as defined in '68.150 prior to June 21, 1999 (three years after publication of the final rule). A worst-case Off-site Consequence Analysis (OCA) performed by Malcolm Pirnie, Inc. (Malcolm Pirnie) indicated that the release of 500 pounds (one 55-gallon drum) of hydrofluoric acid (HF) would result in a distance to the toxic endpoint for HF of approximately 1,000 feet. The OCA indicated that the release of HF under the worst-case scenario would impact public or private entities located beyond TDD's property boundaries. TDD is therefore excluded from Program Level 1 requirements. The TDD facility has a North American In dustrial Classification (NAIC) code of 33422, which does not fall within the range of NAIC codes subject to Program Level 3 requirements. The TDD facility is also not subject to OSHA's Process Safety Management (PSM) standard (29 CFR 1910). TDD is therefore not subject to Program Level 3 requirements. The TDD facility is subject to Program Level 2 requirements since Program Levels 1 and 3 do not apply. '68.155(a) Accidental Release and Emergency Response Policies The TDD facility has policies in place, including both onsite activities and coordination with off-site responders, that must be followed in the event of an oil spill or hazardous materials release. Accidental Release Prevention and Emergency Response policies are available for review by all facility personnel as required under 40 CFR 68 Subpart D. '68.155(b) Stationary Source and Substance Handled The stationary source subject to 40 CFR Part 68 is the TDD drum storage area. The drum storage area houses between fi ve and twenty-five 55-gallon drum containers that store HF at ambient temperature and pressure. All other areas within the TDD facility use HF at concentrations and/or quantities below the threshold amount. The drum storage area is fully diked, and protected by a polymeric coating to protect the concrete in the event of a spill of HF or other corrosive material. A spill response kit containing overpack drums, booms and neutralizing agents are stored within twenty-five feet of the drum storage area for rapid response in the event of a spill. Facility safety procedures dictate that personnel responsible for transporting HF are fully protected by personal protective equipment including fully encapsulating suit, protective chemical gloves, goggles, splash guard and acid mist respirator. Personnel work using the buddy system for safety, and a facility-wide alarm is activated in the event of a spill. The TDD facility maintains a fully trained staff on call 24 hours per day to respond t o hazardous material releases or medical emergencies. The nature of the emergency is communicated to the response staff via the facility-wide alarm system. '68.155) Off-site Consequence Analysis As a Program 2 Process, one worst-case release scenario and one alternative release scenario were assessed for the drum storage area. Worst-Case Release Scenario The facility is required to complete one worst-case release scenario per USEPA 40 CFR Part 68.165(a)(2). Since HF is classified as a buoyant gas in the EPA published Off-site Consequence Analysis Guidance (OCAG) dated May 24, 1996, TDD has chosen to use the OCAG Reference Tables and Equations to calculate the distance to the toxic endpoint. The worst-case release scenario is determined in accordance with the requirements provided in 40 CFR 68.22 and 40 CFR 68.25(b,c). Table 1 presents the required inputs for use of the Reference Tables and Equations. TABLE 1: Worst-case Scenario Date Input List of Input Parameters Refer ence to 40 CFR Part Wind speed - 1.5 m/s (3.4 mph) F atmospheric stability class '68.22(b) Ambient Temperature - 25 :C (77 :F) Humidity - 50% '68.22) Height of Release - 0 feet '68.22(d) Surface Roughness - Urban (1.0 m from Sheih et al., 1979) '68.22(e) buoyant gas model '68.22(f) Temp. of HF gas - 25 :C (77 :F) '68.22(g) Release Quantity - 500 lb '68.25(b)(1) Release Rate - 2.3 lb/min '68.25(c)(1) Release Duration - 10 min '68.25(c)(1) As described in USEPA 40 CFR Part 68.25(b) the worst-case release shall be the greater of the following: (1) the greatest amount held in a single vessel or (2) the greatest amount in a pipe. For the TDD facility the worst-case release is that a single 55-gallon drum (one vessel) ruptures, and its contents escape to outside air for a maximum duration of 10 minutes. Since TDD stores HF containers inside a diked area, the rule allows passive mitigation to be considered for the worst-case release. Diking will reduce the rate at which a gas could be released to the atmosphere if the diked area is less than the area created by an uncontained pool of liquid 1 centimeter deep. Results of Worst-Case Scenario The Reference tables indicate that the toxic endpoint for a release of 500 pounds of HF will occur at 0.19 miles (1,003 feet). The residential population within the 0.19 mile radius of influence was determined to be approximately 4 individuals (one residence) based on a windshield reconnaissance conducted within the impacted area. Alternative Release Scenario The facility is required to complete at least one alternative release scenario per USEPA 40 CFR Part 68.165(a)(2). The alternative release scenario considered is completed in accordance with the guidelines provided in 40 CFR 68.22 and 40 CFR 68.28. Input parameters are presented in Table 2. Table 2: Alternative Scenario Data Input List of Model Input Parameters Reference to 40 CFR Part Wind speed - 3.0 m/s (6.7 mph) F atmospheric stability class '68.22 (b) Ambient Temperature - 25 :C (77 :F) Humidity - 50% '68.22) Height of Release - 0 feet '68.22(d) Surface Roughness - Urban (1.0 m from Sheih et al., 1979) '68.22(e) Buoyant gas model '68.22(f) Temp. of HF gas - 25 :C (77 :F) '68.22(g) Release Quantity - 328 pounds '68.28(b) Release Rate - 4.68 lb/min Release Duration - 10 min '68.25(b) The scenario for the TDD alternative release is as follows: A forklift punctures one drum of HF during unloading outside the drum storage area, causing a hole approximately 1/4-inch in diameter. TDD personnel will respond within 15 minutes. Per the OCAG, the calculation of the liquid release rate for a container rupture is as follows: QR = HA x (LH)= x LF, where: HA = Hole puncture area = 0.05 square inches LH = height of liquid level above puncture in inches = 36 LF = liquid leak factor = 51.6 (calculated value) QR = 0.05 x 6 x 51.6 = 15.5 pounds per minute or 232 pounds in 15 minutes Per the OCAG, alternative rele ase scenarios for aqueous solutions of toxic compounds are to use a release duration of 10 minutes. Calculation of the release rate is presented below: Release Rate (QR) = QS x WF x LFA x DFA, where: QS = Quantity released = 232 pounds WF = wind factor = 3.00.78 m/s = 2.4 m/s LFA= Liquid factor ambient = 0.010 DF = Density factor = 0.39 QR = 232 x 2.4 x 0.010 x 0.39 = 2.17 pounds per minute Results of Alternative Scenario Reference Table No. 12 of the guidance provides toxic endpoint distances for urban areas assuming a release duration of 10 minutes. Toxic endpoint distances are provided based on the ratio of release rate (QR) to toxic endpoint concentration (TEC). For the alternative release scenario, QR/TEC = 135.6 The toxic endpoint distance for the above ratio under the alternative release scenario is 0.06 miles (317 feet). No residences are located within the area covered under this scenario. '68.28 (b)(1) For each scenario required under paragraph (a) of this sec tion, the owner or operator shall select a scenario: '68.28 (b)(1)(I) That is more likely to occur than the worst-case release scenario '68.28 (b)(1)(ii) That will reach an endpoint off-site, unless no such scenario exists. The alternative scenario considered is conservative in that the discharge rate from a ruptured container is assumed to stay constant over the duration of the release. The amount released under this scenario is also considered to be conservative based on facility records. Based on records of in-plant releases, a more realistic release scenario would assume an HF release of 5 pounds. The resultant toxic endpoint distance from this release would be within the property boundaries. '68.155(d) Accidental Release Prevention Program An Accidental Release Prevention Program for oil and hazardous materials is available for review by all facility personnel as required under Part 68 Subpart D. Specific procedures have been prepared by facility health and safety pe rsonnel for the handling of aqueous HF. These procedures are also maintained and updated regularly. '68.155(e) Five-Year Accident History No releases resulting in an off-site impact, as described under 40 CFR Part 68.42(a), have occurred at this facility since it began operation. '68.155(f) Emergency Response Program An Emergency Response Program as required under Part 68 Subpart E is available for review by all facility personnel. Elements of this plan are posted throughout the facility for ready access by personnel during emergency situations. '68.155(g) Safety Improvements Recommendations for safety improvements were identified in the Hazard Assessment (HA) which was performed on May 18, 1999. Recommendations were identified for HF receiving practices within three main categories: Standard Operating Procedures, Maintenance, and Training. Additional recommendations may be made when the HA is updated in five years, or as necessary due to process modifications. |