The Gillette Company - Executive Summary
1.0 SOURCE |
The Gillette Company (Gillette) in St. Paul, Minnesota is subject to the USEPA's Risk Management Program (RMP) for Accidental Chemical Release regulations (40 CFR 68) because the facility has quantities of propane, isobutane and butane mixtures greater than the threshold quantity (10,000 pounds) (CAS Numbers 74-98-6, 75-28-5 and 106-97-8).
The propane, isobutane and n-butane mixtures are used as propellants for cans of hair products. There are two storage tanks within a tank farm that contain the regulated flammables. One tank is 40,000 gallons in size and another is 12,000 gallons in size.
2.0 POTENTIAL RELEASE SCENARIOS
As required by the RMP rule requirements, two specifically defined release scenarios (a worst-case and an alternative-case release) were analyzed. The release scenarios were analyzed based upon the guidance contained in the USEPA's Risk Management Program Guidance for Propane Storage Facilities (the "Propane Guidance"), dated October 1998, and USEPA's
Offsite Consequence Analysis Guidance ("OCAG"), dated May 1996.
2.1 WORST-CASE RELEASE
For the worst-case release, the facility must assume that the entire contents of the largest vessel are released, a vapor cloud forms, and a detonation occurs. The distance to the endpoint (EP) is defined as the distance an explosion from an accidental release will travel before dissipating to the point that serious injuries from short-term exposures will no longer occur. For flammable gases, the EP is an overpressure of 1 psi (at 1 psi, windows will break). The calculated distance to the endpoint for a worst case release of approximately 184,900 pounds of the propane, n-butane mixture extends beyond the facility's property boundary.
Although the worst-case consequence analysis is required by the RMP, it should be considered a highly unlikely event. Design, construction, and operation of the storage tanks is such that catastrophic failure is extremely remote. The storage tank was designed a
nd constructed in accordance with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Section VIII), and was certified and stamped in compliance with the National Board of Pressure Vessel Inspectors (National Board).
The worst-case release scenario is unlikely for the following additional reasons:
* The facility has a preventive maintenance program in place to maintain the ongoing integrity of the vessels;
* The facility has a training program designed to ensure that the system is operated by qualified personnel;
* The area is fenced and locked to prevent tampering.
2.2 ALTERNATIVE-CASE RELEASE
The alternative scenario is considered to be a release of flammable gases that is more likely to occur than the worst-case scenario, and reaches an endpoint offsite.
One of the release scenarios outlined in the "Propane Guidance" was chosen for analysis, which involves a tank truck driver who fails to remove the hoses between the storage tank and the tran
sfer vehicle before moving the vehicle. In this case, the analysis considers the failure of a 25 foot length of unloading hose, 4" in diameter. The active mitigation devices are assumed to work as designed, limiting the release to the contents of the hose. The distance from the explosion where overpressure exceeds 1 psi extends beyond the facility's property boundary.
The alternative release scenario is unlikely for the following reasons:
* The facility has a preventive maintenance program in place to maintain the ongoing integrity of the system; and
* The facility has a training program designed to ensure that the system is operated by qualified personnel, especially during transfer operations.
3.0 PREVENTION PROGRAM
The facility has carefully considered the potential for accidental releases of the flammable gases. To minimize the probability and severity of these mixtures releasing, a prevention program that satisfies the Occupational Safety and Health Administration (OSH
A), Process Safety Management (PSM) of Highly Hazardous Chemicals (29 CFR 1910.119) has been implemented. The key components of the prevention program are summarized below:
* The development and documentation of critical process safety information regarding the hazards of flammable gases, the design basis of the system, and the equipment.
* The performance of a formal process hazard analysis (PHA) on the propellant system using a "What-If" Analysis. A team with expertise in engineering, operations, maintenance, and safety evaluated the existing propellant system in depth and developed recommendations to improve the safety and operability of the system.
* Standard operating procedures (SOPs) are used to provide the basis for proper and safe operation of the critical system components.
* System operators are fully trained in safe operating procedures before they work in each area. The training content is based on the process safety information and operating procedures. The traini
ng program ensures that the operators understand the nature and causes of problems arising from system operations and serves to increase awareness with respect to the hazards particular to the flammables in the process.
* Contractors that are hired to work on, or adjacent to, the covered processes are "pre-qualified" based on their knowledge of the chemicals, understanding of applicable codes and standards, and their demonstrated ability to work safely. In addition, these contractors are periodically evaluated to ensure that they continue to work safely.
* A computerized preventative maintenance program is utilized at the facility. This includes regular inspection and calibration of liquid level sensors, temperature and pressure instruments, switches and shutdown devices that have safety implications.
* Formal authorization systems (i.e., management of change procedures, pre-startup safety reviews) are utilized to ensure that system changes or expansions are as safe as the origina
l design and that an independent recheck confirms that the changes are consistent with the engineering design and in a condition to be safely operated prior to startup.
* Events that might cause an accidental or unexpected release of the flammables are subjected to a formal investigation. The objective of the investigation is to correct deficiencies in such a way as to prevent recurrence.
* Prior to the performance of any hot work (i.e., spark or flame producing operations such as welding, cutting, brazing, grinding), management must approve the work by executing a written hot work authorization permit to verify that precautions to prevent fire have been implemented.
* Planning with the local fire department is conducted to ensure a rapid response to potential incidents with the system or external events, such as floods or tornadoes.
* Prevention program compliance audits are performed every three years to verify that the appropriate management systems are in place and are being pr
operly implemented. Any deficiencies found in an audit is addressed.
4.0 ACCIDENT HISTORY
There have been no accidental releases of the flammable gases at the Gillette facility in the last five years that have resulted in death, injury, or significant property damage on site or off-site death, injury, evacuation, sheltering in place, property damage, or environmental damage.
5.0 EMERGENCY RESPONSE PROGRAM
The Gillette facility has implemented a detailed written Emergency Response Plan (ERP). The ERP is intended to address all emergencies at the facility, including incidents related to a release of flammable gases.