Nomaco Zebulon - Executive Summary
Nomaco Inc., headquartered in Zebulon, NC, is a manufacturer of plastic foam products. These products are used in a variety of applications including packaging, pipe insulation, and assorted consumer goods. The company has a strong commitment to preserving the safety of its employees and surrounding communities, as well as minimizing impact on the environment. As a result of this commitment, Nomaco redesigned the manufacturing process to phase out the use of Hydrochloroflourocarbon -containing gases (HCFCs), which deplete the ozone layer. After much research, Nomaco decided to use isobutane gas as an alternative to HCFCs. Isobutane gas is regulated under the Risk Management Program. |
The regulated substance, isobutane gas, is used in the manufacturing process as a blowing agent. Isobutane has about the same flammability potential as lighter fluid. Two tanks containing the regulated substance are located on the property. The storage capacity of each tank is 4,000 gals. However,
it is an administrative practice to not fill to capacity. The regulated substance is used continuously in the daily manufacturing process. Usage is dependent on the manufacturing process throughput. Due to the flammability potential of the regulated substance, there is a strict no smoking policy inside the building, as well as on the premises. There is a designated smoking area outside away from the tanks.
The safe storage and handling of the regulated substance is guided by specific procedures which address regular maintenance of the storage and handling equipment. In addition to procedures, a sophisticated gas detection system is used to continuously monitor gas levels. The gas detection system includes gas detectors located throughout the manufacturing facility as well as in product storage locations. The gas detection system signals facility personnel of any gas releases reaching 10% of the Lower Explosion Limit (LEL). The gas detection system notifies maintenance personnel
with an audible alarm that a 10% LEL has been detected. Maintenance personnel conduct an investigation to isolate and repair the source of the release or shut it down. At 20% LEL, another audible alarm in maintenance is followed by all warehouse dock doors being opened automatically and the ventilation equipment plantwide being activated. This allows fresh air to circulate throughout the facility. At 50% LEL, an alarm siren is activated throughout the facility alerting all personnel to evacuate. Additionally, the control power allowing the regulated substance to enter the facility is shutdown. The risk of accidental release is therefore minimized.
There have been no accidental releases resulting in an off-site consequence at this facility. The possibility that the entire contents of either storage tank would be released to the environment is slight. In this event, the regulated substance would be quickly off-gassed to the atmosphere. The regulated substance may form a vapor cl
oud until all of the gas is diluted by fresh air. If a flame or ignition source is introduced in the presence of gas vapors, an explosion could occur. The worst case scenario for this facility is that all of the regulated substance is released from either of the storage tanks and a an ignition source is introduced. In this event, a vapor cloud explosion impacting a radius of 0.2 miles (or 1,056 ft) from the storage tank location would occur. This event would involve an off-site consequence to Nomacorc Inc., a manufacturing facility adjacent to Nomaco. The offsite consequence analysis was determined using EPA's RMPComp software. An alternative scenario would be that a vapor cloud fire occurs. Using the EPA's OCA Guidance Tables, it is estimated that a vapor cloud fire would create a radius impact of 0.06 miles (or 317 ft) from the storage tank location. Again, Nomacorc Inc. would be affected by the fire. While either of these events is highly unlikely, Nomaco has put considerab
le effort and resources into utilizing technology to minimize accidental releases.
All Nomaco employees are trained on the hazards of the regulated substance and on the Emergency Response Plan (ERP) for the facility in the event of an accidental release. The ERP identifies those personnel who have specific duties during an evacuation. Those duties include taking the visitor logbook outside, taking roll call, taking the first aid kit outside, or taking a handheld gas detector outside upon exiting the building. There are also designated people who have authority to re-enter the building, make a determination of the situation, and instruct employees to re-enter the building when it is safe. Evacuation procedures have been developed for the manufacturing, warehouse, and office areas. A call box is located outside the building which contains a telephone, a call list of contact information, and a copy of the Emergency Response Plan. Local emergency responders would be called in the eve
nt of an explosion, fire, or medical emergency. However, the facility does maintain a First Aid Team, which is trained to administer first aid and CPR until professional medical help arrives onsite. Upon exiting the building, Nomacorc Inc., the manufacturing facility adjacent to Nomaco, is notified of the evacuation. While the current ERP addresses accidental releases of the regulated substance and fire emergencies, the ERP will be expanded to include procedures for inclement weather, such as hurricanes or tornadoes. An Emergency Action Planning Team has been created to develop these procedures.
Nomaco is in the midst of a major initiative to improve safety. This effort will address: safety measurement, safety communications, accident investigation, engineering safety into the process, consistent standards, improving the support organization, and revitalization of safety teams. Firm management commitment has allowed Nomaco to continue to improve the safety organization.