Safety: Do You Need An MNS?

Jan. 29, 2013
Regulations may not require a mass notification system but it still may be a good idea.

The chemical industry is well aware of the unique and serious safety issues inherent in manufacturing its products. Working on a routine basis with hazardous materials that might be toxic or flammable creates risks to people and property, whether from human error, severe weather, equipment malfunction or a criminal act. Small incidents can grow into disasters if not contained. Among the various practices and systems companies use to reduce the risk of damage and injury are mass notification systems (MNSs).

MNSs consist of warning devices and appliances and can include any or all of the following types of equipment: voice messaging, tone-based systems, visual messaging including secondary strobes and digital signage, automated calling systems that will call a designated list of contacts, paging systems, interconnection with two-way radios for outgoing messaging but also MNS activation and call origination messages, telephone and cell phone systems, interconnection to computer networks to display pop-up messages on computers, and others.

Because MNSs are available in a variety of methodologies and have varying levels of effectiveness, questions arise involving the advantages they offer and how complex a system authorities currently or will require. Surprisingly, considering the risks, government agencies strictly enforce few regulations regarding MNSs. Most systems in place stem from company efforts to protect people and property. However, the regulatory landscape is changing; more government entities are imposing regulations that address safety in chemical plants.

The reason these MNSs still operate the way they do is because governing codes and standards allow them to. As of 2012, the International Code Council (ICC), the National Fire Protection Association (NFPA) and the U.S. Occupational Safety & Health Administration (OSHA) don't have any mandates governing the installation of an MNS in a chemical facility. Some governing bodies do require MNSs in chemical plants, but only for certain types of facilities and locations. For instance, the U.S. Department of Defense requires installation of an MNS; the Unified Facilities Criteria dictates the actual requirements for this system. Also, some authorities have adopted ordinances mandating MNSs for any facilities under their jurisdiction that have hazardous classifications.

OSHA has several standards that can be interpreted in different ways when read separately. For instance, Standard 1910.38 (Emergency Action Plans) says: "An employer must have and maintain an employee alarm system. The employee alarm system must use a distinctive signal for each purpose and comply with the requirements in standard 1910.165." However, OSHA doesn't clearly state what messages should be delivered or what types of visual signals should be used for a specific type of event. Several different tones, verbal messages and visual devices can be used to provide distinctive signals during an emergency situation. For instance, an evacuation tone and message with a clear strobe may mean there's a fire in the facility and occupants must evacuate. Alternatively, an evacuation tone and message with an amber strobe may mean there's a severe weather condition that requires employees to muster in a designated area. Both are distinctive signals and meet OSHA standard 1910.38.

However, meeting the standard for a distinctive signal isn't enough when installing an employee alarm system. Standard 1910.165 (Employee Alarm Systems) requires: "The employee alarm system shall provide warning for necessary emergency action as called for in the emergency action plan, or for reaction time for safe escape of employees from the workplace or the immediate work area, or both." This section requires proper training be provided to correctly respond to the emergency based on the notification signal (tone, message, visual devices or other appliances). The key is that an employee alarm system is only as good as the training that employees and facility occupants receive.

Insurance carriers at this point aren't demanding MNSs. They primarily focus on fire protection. Having a properly listed and installed fire protection system is a must. Any additional notification to personnel within or outside of the facility goes beyond what they require.

Today, companies that are self-insured seem to be a bit ahead of the regulations when it comes to using alarm signals to notify their employees. Many self-insurance plans encourage the use of MNSs and often dictate the type and extent of the systems the company should use.

These self-insured companies recognize the risks they face and how much is at stake in life safety and costs if a disaster occurs. Large firms that have conducted risk analyses discover that a full-scale evacuation and shutdown can cost them from hundreds of thousands to several million dollars. Considering that installing an exterior MNS can range from 75¢ to $1 per square foot, depending on options, features and site conditions, cost is hardly a factor in having a dependable system.

Many firms are using a system that has the capability to alert people inside a defined geographical location and to give law enforcement, fire, emergency medical services, emergency management, and the military the information they need to act appropriately.

Facility-wide tonal systems are the most prevalent — but that doesn't mean they are the best solution. In too many plants, an alarm is difficult to hear in some areas, often because the system doesn't extend to all buildings and grounds. As an example, if a refinery's fire alarm system isn't fully integrated into the plant's MNS, a person in the refinery may not hear the tonal alert.

So, more companies are opting for zonal systems because they more reliably ensure all areas are within range of an active alarm. Another significant advantage of a zonal system is that if an emergency situation is contained and only affects a portion of the facility, a storage building for example, then only the alarm in that zone would be activated. This minimizes the number of people who must stop work and evacuate and the amount of equipment that must be shut down. Should the situation escalate and endanger other areas, those zones can be activated as needed.

This is a huge financial advantage, particularly in a business that operates on small margins. The cost to shut down and restart equipment added to the lost productivity due to a full-scale evacuation can mean a loss of hundreds of thousands of dollars.

A company can further improve the effectiveness of its mass notification efforts by adding voice messaging to a zonal system. This enables communicating information about the emergency situation and providing essential directions on how employees must respond. For example, in the case of a chemical vapor cloud, occupants must know what direction the wind is blowing and where they must go to avoid the advancing vapors. In case of a fire or chemical spill, specific evacuation instructions can be broadcast to warn occupants of the particular areas of the building that are hazardous.

Voice messaging is clearly the preferred system if several important qualifications are met: it must be concise, audible throughout the facility, and intelligible. Intelligibility standards adopted by the ICC and NFPA take into account such attributes as speech and background noise levels, as well as reflections and reverberations from walls, floors or other structures.

Of the national regulatory agencies that could mandate MNSs during construction at chemical facilities, only OSHA is requiring some sites to provide an MNS. Currently, it narrowly focuses on alerting workers at new construction sites to potentially dangerous situations. For example, a high velocity windstorm can be a hazard for crews working on the upper floors of a steel substructure. In most cases, construction sites aren't set up for standard MNSs; therefore it becomes the contractor's responsibility to provide another means of alerting workers — e.g., via two-way radios, pagers, etc., which, of course, are only short-term solutions.

Unfortunately, these requirements aren't documented for contractors to reference. Rather, the need may be noted when OSHA conducts an inspection of the construction site. Factors such as the number of workers and the size of the project impact the inspector's decision to require a site-wide communication system. It's not unusual for OSHA to give the general contractor a week or two to comply. This makes a strong case for investing in the installation of a communication system before construction starts. Ultimately, the responsibility for mass notification falls to the chemical plant owner because it's responsible for costs and schedule.

Chemical companies are increasingly relying on radio systems, textual signs and notification of the neighboring communities.

Some plants require certain staff members to carry a radio at all times. It not only serves as a means to communicate with other personnel on a daily basis but also receives a prerecorded alert message or live instructions on what to do in the case of an emergency. A person receiving an alert message is responsible for relaying this information to people not carrying a radio, typically vendor and contract staff.

Textual signs can do more than convey alert messages. At other times, they can provide information such as the time and date, weather conditions, announcements of company activities or the employee of the month. The objective is to get all people on site to look at the sign every time they pass it and rely on it to give them information.

Notifying neighboring communities if a scenario has the potential to be catastrophic poses two challenges: keeping alerts that are for internal purposes only within the fence line, and communicating effectively with those outside the perimeter when needed. A high-power speaker array system, if designed correctly, can accomplish both. A plant using radios for internal alerts would have to undertake additional tasks to notify surrounding areas. One approach is to go to each residence or building to convey the alert in person. Another involves installing a system using phone lines to auto-dial preprogrammed phone numbers and deliver a prerecorded message. Either way is cumbersome and not the most effective for delivering an emergency message.

The majority of chemical plants aren't required to install and maintain an MNS. However, it still may make sense to put in one. To assist in deciding, a professional designer/engineer should conduct a risk analysis. This involves evaluating a number of key items, including but not limited to: types of emergency events possible at the location, impacts to life, cost of evacuating or not evacuating, full versus partial evacuation, costs to restart operations, severity of the event, and impact on the site. Such an analysis will clarify the risk a facility is taking by not having an MNS as well as the respective costs of putting in and maintaining such a system.

JIM OTTE is a senior communications designer at SSOE Group, Toledo, Ohio. E-mail him at [email protected].

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