Nielsen & Bainbridge - Executive Summary
ISOPENTANE RISK MANAGEMENT PROGRAM (RMP) |
NIELSEN & BAINBRIDGE
FOAM MANUFACTURING PLANT
June 16, 1999
Nielsen & Bainbridge is a foam manufacturing plant located in Bridgeview, IL. The plant uses isopentane
(2-methyl butane) as a foam blowing agent. The foam is utilized for various packaging applications. Since
the plant stores more than the threshold quantity of 10,000 lbs of isopentane onsite, the isopentane process is the only process which is subject to USEPA Risk Management Program (RMP) regulations which are codified in 40CFR Part 68. Isopentane is an colorless volatile liquid with a pleasant mild odor that is listed by the USEPA as a regulated flammable substance for accidental release prevention. Isopentane can be safely utilized under regular plant conditions if handled appropriately with care.
Isopentane is brought into the plant by tanker trailers from an outside vendor. The plant stores the
n a single pressure vessel which is maintained at ambient conditions at a maximum operational
pressure of approximately 20 psig. In the foam manufacturing process, the pressurized gas-phase blowing agent is injected into melted plastic pellets in an extruder at temperatures of 375-440 degF along with some color additives and aging agents. The mixture exits through a specially designed die head with a resultant loss of pressure, allowing the blowing agent to expand to ambient pressure which in turn, transforms the plastic into a foamed material.
Accidental Release Prevention and Emergency Response Policy
The Nielsen & Bainbridge plant is committed to manage and operate the plant in accordance with relevant
USEPA regulations and general good operating practices to ensure minimization of the risk of an accidental
release of isopentane from the foam manufacturing process. The state of Illinois has adopted the OSHA
(Occupational Safety and Health Administration) Process Safety Manage
ment (PSM) program. In response
to this regulation, the plant is aggressively pursuing to proactively implement an OSHA PSM program for the isopentane process. In order to ensure periodic monitoring and continual evaluation of the RMP/PSM program elements being implemented at the plant, the Nielsen & Bainbridge plant has instituted a command-and-control emergency response (ER) organizational structure within the plant. In addition to their regular duties, members of this structure have additional RMP/PSM-related responsibilities to consolidate the long-term management of the RMP/PSM program.
However, at this time the PSM exercise is still in progress and certain PSM-related elements have not been
fully addressed in this RMP submittal. But Nielsen & Bainbridge is confident that the PSM exercise will be
complete within the next thirty to sixty days. Then the plant will be submitting a revised RMP (incorporating the PSM elements) for the isopentane process within forty-five to sixty
days from the date of submittal of this RMP.
Worst-case Release Scenario
The worst-case release scenario was assumed to be the complete loss of contents of the 32,500 lbs
isopentane storage tank which is located outdoors. In this analysis, no applicable passive mitigation
measures were accounted for. Typically, the USEPA guidance for defining a worst-case release scenario
for all regulated flammable substances is to assume that the worst-case release results in a vapor cloud
containing the total quantity of the substance that could be released due to a pipe or vessel failure. Then for the worst-case consequence analysis, it must be assumed that the vapor cloud detonates. Thus, the quantity of isopentane available for the vapor cloud explosion (VCE) was given as 32,500 lbs. The worst-case accidental release was modeled using USEPA's public-domain RMP*Comp model to determine the
distance to the endpoint of 1 psi overpressure. The endpoint distance does go offsite, but only nomin
It should also be noted that Nielsen & Bainbridge plant employees regularly inspect the isopentane storage
tank for potential leaks and overall structural integrity. In addition, the process is equipped with explosion-
proof pumps and reinforced piping. This effort minimizes the chance that the isopentane storage tank would fully discharge its contents in an accidental release that would result in an offsite impact.
Alternative Release Scenario
Based on discussions with Nielsen & Bainbridge plant personnel, the following alternative release scenario
was modeled - a complete rupture of the 2.0-inch diameter line from the isopentane storage tank to the
process. The line rupture was assumed for a duration of 15 minutes till appropriate mitigation could be
applied. This active mitigation would be manifest as an emergency shutoff valve which would be activated
by trained plant personnel wearing PPE with the onset of a preset line pressure departure.
The above alternative rele
ase was modeled using USEPA's public-domain RMP*Comp model to determine
the maximum distance to the endpoint of the lower flammability limit of 1.4% due to a vapor cloud fire. The endpoint distance does go offsite, but only nominally. In reiteration, it should also be noted that Nielsen & Bainbridge plant employees regularly inspect the isopentane storage tank for potential leaks and overall structural integrity. In addition, the process is equipped with explosion-proof pumps and reinforced piping. This effort minimizes the chance that piping from the isopentane storage tank would rupture and discharge significant quantities of isopentane in an accidental release that would result in an offsite impact.
Accidental Release Prevention Program
At this time, the Nielsen & Bainbridge plant is proactively implementing an OSHA Process Safety
Management (PSM) program (codified in 29CFR Part 1910.119) for the isopentane process. The scope of
the PSM program encompasses various facets of acc
ident release prevention, e.g., it engenders employee
participation, increases employee awareness about the hazards of handling isopentane, establishes safe
standard operating procedures and enhances access to process safety information. In June 1999, the plant will perform a PSM audit and a HAZOP process hazards analysis (PHA) on the isopentane system with the help of an outside consultant in order to review existing operating procedures, equipment maintenance schedules, operational safeguards and identify action items to render the process safer. Following the PHA, the plant is investing in developing a written PSM program with the help of an outside consultant. The written PSM program will provide the procedural backbone for various safe operability functions (i.e., continual review of safe operating procedures, review of mechanical integrity of equipment, improved maintenance schedules, increased training, better access to process safety information and hazard awareness for both
employees and onsite contractors, and effective emergency response planning) and thereby, allow the plant to maintain, review and evaluate the program on a periodic basis.
In addition, the plant will soon invest in completing an upgrade of the isopentane safety system. Additional
check valves and emergency shutoffs will be installed to mitigate accidental releases of isopentane. These system upgrades should complement the organizational and procedural aspects of the prevention program which will hopefully minimize the risk of an accidental release of isopentane from the Nielsen &
Bainbridge plant process.
Five-year Accident History
Isopentane has replaced freon as a foam blowing agent at the Nielsen & Bainbridge plant over the last two
years. The plant has had no reportable isopentane releases during the period it has been in use in the plant.
Emergency Response Program
The Nielsen & Bainbridge plant has already instituted emergency procedures for responding to and
cidental releases of hazardous chemicals stored and used onsite such as, isopentane. As part of the written PSM program, the plant will adapt the aforesaid emergency procedures as being adequate and compliant in satisfying the need for Emergency Planning and Response to conform to applicable PSM
regulations. Since it would be counterproductive to develop a separate emergency response plan under
RMP regulations, the plant has developed an Emergency Response Program (ERP) that has adopted the
existing emergency procedures and added elements to ensure compliance with relevant RMP Part 68
requirements of the RMP rule.
The Nielsen & Bainbridge plant has developed a well delineated emergency response (ER) organization
under the command of the Emergency Response Coordinator (ERC, typically the Director of Operations) or
his designee with a set of clearly defined responsibilities and procedures for ER team members. ER team
members are regularly appraised, receive updated training and
conduct practice emergency response drills on a scheduled basis. Besides onsite training and practice, ER team members are responsible for
coordinating emergency response activities (e.g., agency notification) with local emergency responders
such as the Bridgeview Fire Department (the LEPC) through established channels of communication. The
ERP contains detailed notification procedures that are followed and practiced by ER team members.
The plant has also developed detailed evacuation procedures customized for the plant in the event of an
accidental release of isopentane. Upon notification of evacuation orders from the ERC, the evacuation
team will initiate and supervise evacuation procedures for both onsite employees and contractors. To ensure the efficacy of the ERP, the plant has designated a READYROOM which will be the operational nerve center and communications center during an accidental release emergency. The READYROOM is
equipped with the appropriate emergency respons
e equipment in readiness for immediate application.
Changes to Improve Safety
The Nielsen & Bainbridge plant is committed to supporting the emergency response (ER) organization and
its prescribed functions in the event of an accidental release. ER team members are drawn from the existing employee pool and the organizational concept fosters pride and emphasizes concerns for safe operation of the plant. Ultimately, any safe operation is a grassroots movement that must be nurtured within the plant perimeter with the employees themselves. The addition of a well defined ER organization at the Bridgeview plant operating in conjunction with local emergency responders such as the Bridgeview Fire Department should greatly alleviate any safety concerns about handling isopentane at the plant.
In addition, the Nielsen & Bainbridge plant will soon be completing an upgrade of the isopentane safety
system. Additional check valves and emergency shutoffs will be installed to mitigate accidental re
isopentane. Thus, in addition to new and improved training and organizational changes, this
equipment and mitigation system upgrades to the isopentane system demonstrates the commitment to safety that Nielsen & Bainbridge has made to both the Bridgeview plant employees and the surrounding