AUTHOR: Valerie Ziavras


What is Hazardous Material?

Which code or standard applies to hazardous materials? How much of a particular hazardous material can be stored or used? What floor of the building can that hazardous material be stored or used on? These are all questions some are faced with daily. There is an assumption that people, such as facility managers, building owners, engineers, and first responders, just inherently know when a material is a hazardous material. And, that once they know it is a hazardous material, they know how to deal with that material properly and safely. We have seen the potential impacts of materials that are improperly stored or used such as in the 2013 fire and explosion at West Fertilizer Company in Texas. How can we prevent incidents like this from happening? The first step is knowing how to identify a hazardous material. Part of the challenge when it comes to determining and classifying hazardous materials is that there is not one consistent definition of “hazardous material” nor is there one consistent approach to the classification of hazardous materials. Therefore, when looking at Safety Data Sheets (SDS) or literature provided by the manufacturer, it is imperative to know and understand which hazardous material classification system is being used. NFPA 400, Hazardous Materials Code, has its own definition and classification method that consists of 14 different categories. The U.S. DOT uses a 9-category classification system. OSHA has its own definitions established in 29 CFR, which has been revised to align with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).  While there has been an effort to coordinate between the groups, differences do still exist. Information on SDS is often based on the GHS system and not the system in NFPA 400. Defining Hazardous Material The approach I like to take is to assume materials are hazardous, until I have proven that a particular material is not. As we will discuss there are a number of different definitions and triggers that could lead to a material being considered hazardous. Therefore, I would not want to rely on an initial assumption that a material is not hazardous. When determining if a material is to be considered hazardous, the first step is to identify for what purpose you are evaluating the material for. If you are transporting the material in the United States then the DOT’s definition is what you would need to use, whereas if you are storing or using the material, then you would need to use the definition found in the applicable building code or fire code. GHS does not define the term “hazardous material”, but the DOT defines a hazardous material as “means a substance or material that the Secretary of Transportation has determined is capable of posing an unreasonable risk to health, safety, and property when transported in commerce, and has designated as hazardous under section 5103 of Federal hazardous materials transportation law (49 U.S.C. 5103). The term includes hazardous substances, hazardous wastes, marine pollutants, elevated temperature materials, materials designated as hazardous in the Hazardous Materials Table (see 49 CFR 172.101), and materials that meet the defining criteria for hazard classes and divisions in part 173 of this subchapter.” NFPA 1, Fire Code, NFPA 101, Life Safety Code, and NFPA 5000, Building Construction and Safety Code, all use the definition from NFPA 400 for hazardous material. NFPA 400 defines a hazardous material as: A chemical or substance that is classified as a physical hazard material or a health hazard material, whether the chemical or substance is in usable or waste condition.  The definitions of physical hazard material and health hazard material are integral in understanding and properly applying this definition. A physical hazard material per NFPA 400 is a substance that is classified as any one of the following: Explosive Flammable cryogen Flammable gas Flammable solid Ignitible (flammable or combustible) liquid Organic peroxide Oxidizer Oxidizing cryogen Pyrophoric Unstable (reactive) Water-reactive material A health hazard material per NFPA 400 is a chemical or substance that is classified as any one of the following: Toxic Highly toxic Corrosive material Many of these terms are defined within NFPA 400 to further help in defining what a hazardous material is. It is also worth noting that other NFPA codes and standards may use a different definition for “hazardous material”. That is why it is essential to understand for what purpose (e.g., offsite transportation, storage, use, etc.) you need to determine whether something is a hazardous material or not and then consult the appropriate document to determine if it meets the definition. There is not one universally accepted definition. One example of a document that defines hazardous material differently is NFPA 30, Flammable and Combustible Liquids Code. NFPA 30 defines hazardous material or hazardous chemical as a “material presenting dangers beyond the fire problems relating to flash point and boiling point.” The annex material goes on to explain that the other dangers could include things like toxicity, reactivity, instability, or corrosivity. However, that is not intended to be an exhaustive list.  While this may seem to conflict with NFPA 400, when you consider the scope of NFPA 400 the definition from NFPA 30 actually aligns with how NFPA 400 is applied. Although a flammable and combustible liquid that has no other physical or health hazards would be considered a hazardous material per NFPA 400, it is excluded from the scope of the document. I’ll talk more about this in a future blog where we will look in detail at the scope and applicability of NFPA 400.  Classifying Hazardous Materials As I mentioned earlier, different organizations have different ways of classifying hazardous materials. The DOT uses a 9-system classification method while NFPA 400 uses a 14-system category method. Some of the DOT classifications are further broken into divisions, while some of the NFPA 400 categories are broken into subclassifications. The 9 classes used by the DOT are: Class 1: Explosives Class 2: Gases Class 3: Flammable Liquid and Combustible Liquid Class 4: Flammable Solid, Spontaneously Combustible, and Dangerous When Wet Class 5: Oxidizer and Organic Peroxide Class 6: Poison (Toxic) and Poison Inhalation Hazard Class 7: Radioactive Class 8: Corrosive Class 9: Miscellaneous The 14 categories of hazardous materials used in NFPA 400 are: Corrosive solids, liquids, or gases Flammable solids Flammable gases Flammable cryogenic fluids Inert cryogenic fluids Inert gases Organic peroxide formulations Oxidizer solids or liquids Oxidizing gases Oxidizing cryogenic fluids Pyrophoric solids, liquids, or gases Toxic or highly toxic solids, liquids, or gases Unstable (reactive) solids, liquids, or gases Water-reactive solids or liquids Compounding the challenge associated with determining and classifying hazardous materials, is the fact that between the two systems many of the categories use similar verbiage but may have different thresholds that trigger that particular classification.  One example is flammable liquid. DOT defines flammable liquid as “a liquid having a flash point of not more than 60 °C (140 °F), or any material in a liquid phase with a flash point at or above 37.8 °C (100 °F) that is intentionally heated and offered for transportation or transported at or above its flash point in a bulk packaging”. NFPA 400 states that a flammable liquid is an ignitible liquid that is classified as a Class I liquid. There are three subclassifications of a Class I liquid. The table below summarizes the specific thresholds for the subclassifications. Subclassification Flash point Boiling point Class IA Liquid Below 73 OF (22.8O C) Below 100 OF (37.8O C) Class IB Liquid Below 73 OF (22.8O C) At or above 100 OF (37.8OC) Class IC Liquid At or above 73O F (22.8O C) but below 100O F (37.8O C N/A These discrepancies mean that when determining the category of hazardous material you have, you need to know what system was used to provide a classification, such as the one found on a Safety Data Sheet, or you need the actual test data so the classification can be determined based on the definitions. In summary, although there is agreement that hazardous materials are physical or health hazard materials, there is not one standard definition or approach to determining if a material should be considered hazardous or not. NFPA 400 defines hazardous material as any chemical or substance that is a physical hazard material or a health hazard material. Hazardous materials are then categorized based on the physical or health hazard they present. There are 14 different categories in NFPA 400 and a material may fall into one or more of those categories. Be on the lookout for my future blogs which will take a deeper dive into NFPA 400, covering topics like applicability of NFPA 400, maximum allowable quantities (MAQs), and more.
NFPA Fire & Life Safety Ecosystem

Vacant Buildings

Late last month, three firefighters were killed and another was injured when a vacant rowhome partially collapsed in Baltimore, MD. Unfortunately, this isn’t the first time firefighters have lost their lives while responding to a fire in a vacant building. Six firefighters died in Worcester, MA when a fire broke out in a vacant cold storage warehouse in December of 1999. In another tragic incident two firefighters lost their lives when responding to a fire in an abandoned warehouse in Chicago, IL in December of 2010. These are only a few examples, according to a 2018 NFPA report, which shows that between 2011 and 2015, fires in vacant buildings accounted for 6% of structures fires but 13% of firefighter injuries. Whenever tragedies like these occur, everyone wants to know why and what can be done to prevent this from happening again. Often, there is not just one issue that led to the event but rather a number of shortcomings. To help explain how situations like this can arise, and highlight the different roles and responsibilities people have, NFPA introduced in 2018, the NFPA Fire & Life Safety Ecosystem™. It is a comprehensive framework that identifies eight key components that must work together to help prevent loss, injury, and death from fire, electrical, and other hazards. The components include the development and use of current codes, government responsibility, referenced standards, investment in safety, a skilled workforce, code compliance, preparedness and emergency response, and an informed public. A lack of attention to any one of these components results in greater risks and can create a significant safety threat. When I think of these incidents in vacant buildings there are four main components of the ecosystem that come to mind that play major roles in reducing the risk of something like this happening: Preparedness and Emergency Response, Code Compliance, Informed Public, and Government Responsibility.  Preparedness and Emergency Response is important because it addresses the pre-planning and training responders receive. It is imperative that first responders know which buildings in their area are vacant and what the response plan is. Vacant structures can pose hazards to emergency responders as they’re no longer being properly maintained, inspected, and repaired. Structures in this type of disrepair will provide less inherent fire resistance leading to collapse earlier in a fire. This is further compounded as vacant is not synonyms with unoccupied. Left unsecured, vacant structures can present an opportunity for trespassers. These risks can only be reduced so much by pre-planning, training, and policies within the emergency response community. It takes the entire fire and life safety ecosystem working together to best address these risks.  Often, it is thought that codes and standards can address safety challenges all on their own. However, safety is a system, and each part of the system relies on the others for tragedies to be avoided. On the code side, NFPA 1, Fire Code, has requirements aimed at addressing the challenges associated with vacant buildings. Limit fuel load: The first is limiting the fuel load. Vacant buildings are required to be clear of all combustible storage, waste, refuse, and vegetation. The idea is that even if a fire occurs in a vacant building, if there is a limited fuel load, the fire will not be able to spread due to the lack of combustibles. The second is to limit access to the structure. Restrict access: Vacant buildings should be locked, barricaded, or secured some other way from unauthorized people entering. By limiting access to the structure, the risk of arson or accidental fire is reduced. Additionally, it reduces vandalism. Maintain fire protection systems: The last major component of the code requirements is that all fire protection systems must be maintained in vacant buildings, unless otherwise approved by the Authority Having Jurisdiction (AHJ). The idea is that if a fire were to start, the systems would help minimize the damage. If the building has a sprinkler system, the fire may be extinguished even though the building is empty. Or, if there is a fire alarm system the fire department may be notified sooner than if the system had been disabled. For more specific details of the code requirements see this blog. As the NFPA Fire & Life Safety Ecosystem shows, code requirements are not the only part of what is needed to ensure fire and life safety. The code requirements need to be adhered to and that is where code compliance comes into play. Enforcing codes and standards and ensuring ongoing inspections reduces deaths, injuries, and losses. This can be extremely challenging when it comes to vacant buildings but a strong means of enforcing the codes and standards helps mitigate building owners not complying with the requirements.  The third component of the NFPA Fire & Life Safety Ecosystem that can have an impact on preventing these types of incidents is an Informed Public. Many people think of a vacant building as just an empty building with minimal risk since there is no one inside. Yet, we know vacant buildings aren’t always empty which means firefighters may still need to search the building upon arrival. These buildings, if not well maintained may be more susceptible to collapse. If the public, including the building owner, understands the hazards associated with a vacant building, they are more likely to ensure they understand the need to abide by the code requirements such as keeping combustibles out of the building and ensuring unauthorized people do not access the site.  The final component of the NFPA Fire & Life Safety Ecosystem is government responsibility. Government has a responsibility to keep their communities safe from fire, electrical, and other hazards. They must create a policy and regulatory environment where laws, policies, and spending priorities are dictated by public safety needs. It is what the public expects. Government officials also have a duty to do all they can to keep first responders safe. Those first responders lay their lives on the line every day for the people they serve. Like so many aspects of fire and life safety, when it comes to protecting vacant buildings, many components need to work together in order to minimize the hazards associated with these buildings. A well-functioning Fire & Life Safety Ecosystem can go a long way to better protecting the public and our first responders. Learn more about the Ecosystem at 

Occupant Notification Strategies

A fire alarm system is intended to notify occupants and, often, the responding personnel to an emergency. During the initial stages of the system design, it is important to answer the following questions:  who needs to be notified; what do they need to know; when do they need to know it; where will they be; and why do they need to know? The answers to these questions will determine the most appropriate type of notification strategy. Occupant notification may be in one of two modes, public or private and there are additional options such as selective notification, a presignal feature, and positive alarm sequence to address unique situations. Many of these alternative designs require authority having jurisdiction (AHJ) approval. Public mode Public mode fire alarm systems are what most people think of when they think of a fire alarm. Once an alarm is received from an initiating device, the building goes into alarm, all occupants are notified, and evacuation begins. In NFPA 101®, Life Safety Code® this is the base requirement. Selective notification Sometimes it is impractical for an entire building to be emptied at once. We commonly see this in high-rise buildings where it would take too long for all occupants to evacuate. Therefore, to prioritize the evacuation of the occupants closest to the danger, selective notification can be used in a public mode system. Typically, this strategy allows the fire floor and one or two floors above and below the fire floor to be notified. Then, if the fire continues to progress, additional floors are evacuated. This method minimizes the number of people in the means of egress, allowing first responders access to the emergency, and gives priority to those occupants at highest risk. Per NFPA 101, this type of evacuation strategy is permitted wherever the total evacuation of the building occupants is impractical because of the building’s configuration and where the evacuation strategy has been approved by the AHJ. Many high-rise buildings use this strategy. Private mode A private mode fire alarm system only notifies those concerned with implementing emergency actions. Some situations where it may be permitted include where people are incapable of evacuation, such as hospitals or where people are not allowed to evacuate, such as prisons. For a detailed description of private mode fire alarm systems be sure to read this blog. If you are looking for a more high level overview of public mode vs private mode be sure to check out this blog. Presignal feature A presignal feature allows the initial fire alarm signal to sound only in department offices, control rooms, fire brigade stations, or other constantly attended central locations. The initial signal is also transmitted to the supervising station if there is a connection. After the initial signal, the rest of the system is operated either by a person actuating the general alarm, or a feature that allows the control equipment to delay the general alarm by more than 60 seconds after the initial alarm. These types of systems are permitted in NFPA 72®, National Fire Alarm and Signaling Code® and in NFPA 101 where the specific occupancy chapter allows it and where the initial fire alarm signal is automatically transmitted, without delay, to a municipal fire department and to an on-site staff person trained to respond to a fire emergency. The initial signal also needs to be transmitted to a fire brigade, if one is provided. Although the presignal feature may delay notifying occupants, it does not delay alerting the responding fire department or brigade. An example of an occupancy that allows this feature is existing assembly occupancies. Positive alarm sequence A positive alarm sequence is another option. This option allows delaying the notification of the responding fire department where other trained individuals are available to investigate alarms.  Examples of trained individuals include security personnel and private fire brigades. In a positive alarm sequence, the signal from an automatic fire detection device must be acknowledged by a trained professional at the fire alarm control unit within 15 seconds. Once acknowledged, the trained professional has up to 180 seconds to investigate the alarm. If fire is not found, then the trained professional can reset the system. If the system is not reset, a second automatic fire detection device initiates, or any other fire alarm initiating device actuates, then the building will go into alarm and occupants will be notified in accordance with the building’s evacuation or relocation plan. Per NFPA 101, this type of alarm sequence is allowed with occupancy permission. An example of an occupancy that allows its use is new and existing educational occupancies. Summary It is essential to effectively notify occupants and responding personnel during emergencies. NFPA 72 and NFPA 101 fire alarm systems allow for both public and private mode notification to accomplish this, with options for presignal, positive alarm sequencing, and selective notification. Understanding the unique situation of a particular building will allow you to accomplish this most effectively. 
Vertical opening

Types of Permissible Vertical Openings

The Life Safety Code, NFPA 101, aims to protect the life safety occupants by minimizing their exposure to fire, smoke, and its effects. One of the ways this is done is through building compartmentation. To limit the spread of fire, smoke, and its effects one of the base requirements of the Life Safety Code is that every floor that separates stories in a building must be constructed as smoke barriers. However, some openings in these smoke barriers are necessary for the functionality of the building while others are for convenience or aesthetics. These openings can provide a pathway for fire and smoke to travel vertically through the building. To minimize the spread of fire and smoke vertically throughout the building, openings in these separations are limited to those specifically identified in the Life Safety Code. Ultimately, they allow the effects of fire to impact occupants on other floors who would otherwise be protected if it weren’t for these openings. In addition to limiting the types of openings, the vertical openings must be protected to minimize the spread of the effects of fire. Pipe Penetrations and Expansion or Seismic Joints Pipes, cables, conduits, and similar items must run vertically through the building to allow utilities to reach all areas of the building. Similarly, vertical openings created by expansion or seismic joints are necessary for the structural integrity of a building. Any type of vertical openings created by pipe penetrations must be protected with a listed firestop system or device which must also limit the transfer of smoke. Expansion or seismic joints must be listed showing that it is designed to prevent the penetration of fire. Shafts Shafts are used for a variety of reasons, such as for elevators, pipes, mechanical equipment, and even stairs. Shafts must be separated from the building with fire-resistance rated walls and typically extend from the top of the building all the way to the bottom of the building. The fire-resistance rating of the walls will depend on if it is a new or existing shaft and the number of stories it connects. If the shaft does not extend through the entire building, then it must terminate at construction of equal or higher fire resistance rating. Atrium  Atria are a type of vertical opening that are used for convenience and/or aesthetics. They are some of the largest vertical openings you might see in a building and recognized by NFPA 101. An atrium is permitted to be open to any number of stories and can be located anywhere in the building.  The atrium must be separated from the remainder of the building with 1-hour fire-resistance rated walls. Glass walls are permitted to be used instead of the rated walls provided a number of other conditions are met. The entire building must be protected by a supervised automatic sprinkler system. Only low- or ordinary-hazard contents are permitted within the atrium. Additionally, atriums, other than existing, previously approved atriums, must have an engineering analysis that shows that the smoke layer interface stays a safe distance above the highest unprotected opening or the highest walking surface. If the engineering analysis shows that the smoke layer interface can’t be kept high enough, then a smoke control system is required. Communicating Space A communicating space is sometimes referred to as a “mini-atrium”. Although the protection scheme is different, they may look very similar. The major differences are the number of stories they connect and the location in the building. A convenience opening can only connect three or fewer adjacent stories (to connect three stories, at most two floors would have openings in them) with either the lowest floor or the next to the lowest floor of the communicating space being a street floor. Protecting occupants in a communicating space relies on the space either being open and unobstructed providing occupants with a high level of awareness of what is happening in the space, or the space must be open and have smoke detection. Smoke detection ensures occupants within the communicating space have an early indication of fire or other emergency condition and can react appropriately. The egress capacity within the communicating space must be sufficient for all occupants, on all levels within the communicating space, to egress at the same time and every occupant within the space must have access to at least one exit without having to travel vertically through the communicating space to get to one. Occupants not in the communicating must have access to at least one exit without having to travel through communicating space. The communicating space must be separated from the rest of the building by 1-hour fire-resistance rated walls unless the building is fully sprinklered. Lastly, the contents within the communicating space are limited to low-hazard contents unless there is an automatic sprinkler system, then the contents can be ordinary-hazard. All occupancies, with the exception of healthcare permit this type of vertical opening.     Allowable Locations for Communicating Spaces   Convenience Opening In some cases, for convenience or aesthetic purposes, building owners may want a vertical opening between fewer floors. Convenience openings are another vertical opening option. They connect two adjacent stories, piercing only one floor.  If travel is permitted within the convenience opening, it cannot be considered part of the required means of egress. The opening must be separated from other unprotected vertical openings and separated from corridors by construction that is equivalent to what the occupancy chapter requires for corridor wall separation. For new construction, if the occupancy does not require fire-resistance rated corridor separation then the convenience opening must be separated from the corridor by a smoke partition.  Convenience Stair Convenience stairs are permitted to connect no more than 4 contiguous stories for new construction. An example of a convenience stair opening would be if you had a four-story business occupancy that had unenclosed stairs that allowed for travel between all four floors. Although similarly named, the protection requirements for convenience stairs are different than the protection requirements for convenience openings and thus you are permitted to have more floors open to each other. Convenience stairs cannot serve as part of the required means of egress (exit access, exit, or exit discharge), the building must be protected with a supervised, automatic sprinkler system, and the opening has to be protected with closely spaced sprinklers and a draft stop as outlined in NFPA 13. When used in new construction, the size of the opening is limited to less than twice the horizontal projected area of the stairway. Two-Story Opening with Partial Enclosure A two-story opening with a partial enclosure is permitted in all occupancies. On one floor, the opening must be separated from the remainder of the floor by fire-resistance rated walls and a fire-protection rated door. On the other floor, the enclosure is open to the floor. This separation prevents the spread of fire and smoke on one of the two levels from spreading to the other floor. It is up to the designer to choose which floor the opening is separated from and which it is open to.   Two-Story Opening with a Partial Enclosure on the 2nd Floor Mezzanine A mezzanine is a partial floor level between stories. The mezzanine itself is not considered a story where it meets certain area limitations and openness requirements. Additional requirements such as supervised automatic sprinkler protection and access to exits are driven by the size and design of the mezzanine. Mezzanine Escalator There are a few options of how to protect a vertical opening created because of the presence of an escalator. One of the more common methods is to provide protection in accordance with NFPA 13 through the use of closely spaced sprinklers and a draft stop around the opening. Conclusion Vertical openings need to be properly protected in order to minimize the number of occupants on other floors that are exposed to fire, smoke, and its effects. Here, the high-level requirements for the more common types of vertical openings are provided. Section 8.6 of NFPA 101 provides additional details for how these openings need to be protected as well as requirements for some less common types of openings. 

The Basics of Sprinkler Thermal Characteristics

There are many different decisions that need to be made when it comes to designing a sprinkler system, such as what type of sprinkler system should be installed (check out this blog for more information on that topic), what type of piping should be used, and even which sprinkler should be selected. When manufacturers have well over a hundred different types of sprinklers it can be challenging to know which one to choose. Certain sprinkler characteristics will help determine which is an appropriate type for your specific situation. NFPA 13 Standard for the Installation of Sprinkler Systems identifies a number of sprinkler characteristics including thermal sensitivity, temperature rating, k-factor, installation orientation, water distribution characteristics, and special service conditions. While these are all important, I’m going to focus on two particular sprinkler characteristics, thermal sensitivity and temperature rating. Thermal Sensitivity The thermal sensitivity of a sprinkler measures how quickly the thermal element operates. Perhaps the most common way of measuring thermal sensitivity is the response time index (RTI). Sprinklers are then categorized into fast or standard response based on their RTI. The RTI is typically determined by conducting a plunge test in which a sprinkler is placed (plunged) into a heated laminar airflow within a test oven. Then, the operating time of the sprinkler, the operating temperature of the sprinkler’s heat-responsive element, the air temperature of the test oven, the air velocity of the test oven, and the sprinkler’s conductivity factor are used to calculate the RTI. Additional factors impact the response such as the temperature rating of the sprinkler, sprinkler position, fire exposure, and radiation. Category RTI (meters-second)1/2 [(ft-sec)1/2] Fast Response 50 or less (90 or less) Standard Response 80 or more (145 or more) There are also different types of fast response sprinklers. You may have heard of quick response or residential sprinklers. Both of these are fast response type sprinklers meaning they have an RTI of 50 meters-second1/2 or less, but they are considered different types of sprinklers because although their RTI is similar the performance characteristics and design parameters are different. RTI can also be expressed in (ft-sec)1/2 but the metric version is most common. While this is all important to understand, the real question is, what does this mean when selecting sprinklers? Certain situations require specific types of thermal sensitivity ratings per NFPA 13, but we are going to focus on the broader concept of why you may choose a fast response sprinkler over a standard response sprinkler or vice versa. It should be noted that a number of other factors will impact when and how quickly a sprinkler operates under true fire conditions. Variables such as ceiling height, spacing between sprinklers, ambient room temperature, and the distance the sprinkler is below the ceiling will all impact the time to operation. However, if all these elements are held constant, a fast response sprinkler would operate before a standard response sprinkler. In some situations, such as in a light hazard occupancy this is ideal. Since a low hazard occupancy has a low quantity and combustibility of contents, we expect the fire growth to be relatively slow when compared to other hazard classifications. Therefore, a fast response sprinkler will open earlier and be able to control the fire. In some situations, opening earlier is not ideal and therefore a standard response sprinkler is preferred, or even required. In certain storage applications, where fire growth is much faster, if fast response sprinklers are used additional sprinklers may be opened than the system was designed for. This could result in lower amounts of water and pressure flowing from each sprinkler resulting in less water over the actual fire and ultimately causing the sprinkler system to be ineffective in controlling the fire. If standard spray sprinklers were used, less sprinklers would operate, and this could provide enough time for those sprinklers to control the fire before others operate. Temperature Rating Looking closely at sprinklers with glass bulbs, you may have noticed that there are different color bulbs. The colors identify the temperature rating of the sprinkler. The temperature rating of the sprinkler selected needs to consider the maximum ambient ceiling temperature as well as the occupancy classification. If the maximum ambient ceiling temperature isn’t considered, it could result in accidental sprinkler operation since sprinklers are activated by heat. If the sprinkler does not have a glass bulb, then the frame arm, deflector or coating material will usually have some color indicating the temperature rating. zA Temperature classifications range from ordinary which has a temperature rating of 135-170OF (57-77OC) to ultra-high which has a temperature rating of 650OF (343OC). Typically, ordinary or intermediate which has a temperature rating of 175-225OF (79-107OC) sprinklers are required to be installed unless a certain situation calls for a higher temperature classification. Some examples of situations that require higher temperature ratings are sprinklers installed in commercial-type cooking equipment and sprinklers installed within certain distances of heat sources. Max Ceiling Temperature oF (oC) Temperature Rating oF (oC) Temperature Classification Glass Bulb Colors Color Code 100 (38) 135-170 (57-77) Ordinary Orange or Red Uncolored or Black 150 (66) 175-225 (79-107) Intermediate Yellow or Green White 225 (107) 250-300 (121-149) High Blue Blue 300 (149) 325-375 (163-191) Extra High Purple Red 375 (191) 400-475 (204-246) Very Extra High Black Green 475 (246) 500-575 (260-302) Ultra High Black Orange 625 (329) 650 (343 Ultra High Black Orange Conclusion At first glance, thermal sensitivity and temperature rating may seem like they address the same concern. However, they do not. Thermal sensitivity dictates how quickly a sprinkler will operate while temperature rating is based on the ambient ceiling temperature. In both cases though, it is important that all sprinklers in a given compartment have the same thermal sensitivity and the same temperature rating. Mixing can cause a phenomenon known as skipping. We expect the sprinkler closest to the fire to operate first. If that sprinkler alone isn’t able to control the fire, then we would expect the next closest sprinkler(s) to operate. This pattern would continue until enough sprinklers have opened to control the fire.   However, if different thermal sensitivities or temperature ratings are used, instead of the closest sprinklers operating, you could have a situation where a sprinkler closer to the fire does not operate and a sprinkler further away does. This is known as skipping and can have negative consequences on the performance of the system.     It should be noted that only a mix of ordinary- and intermediate-temperature sprinklers are permitted throughout a building unless a specific situation requires the use of a higher rated sprinkler, such as proximity to a heat source or high ambient ceiling temperatures.
A street with high rises

Occupancy Classifications in Codes

One of the most critical steps in applying NFPA 101, Life Safety Code, and other building and fire codes to a space is identifying the correct occupancy classification. The occupancy classification drives the requirements for many different fire and life safety features. These requirements reflect the unique and expected characteristics of the anticipated occupants of that space such as, capability of self-preservation, familiarity with the space, age, and alertness. Improperly classifying a building or space risks over- or under-applying necessary code requirements, resulting in buildings lacking fire and life safety features, or containing additional fire and life safety features that are not required by the Code. While the majority of the NFPA developed codes and standards use occupancy classifications consistent with the Life Safety Code, including NFPA 5000, Building Construction and Safety Code, other organizations’ codes and standards may differ. This can create challenges for the designer when multiple codes and standards are applicable and enforced in a jurisdiction. Perhaps one of the more common scenarios is when both the International Building Code (IBC) and the Life Safety Code apply. Below is a table comparing the different occupancy classifications between the IBC and NFPA 101/5000. One thing to note is that although some of the occupancies seem to correlate obviously, there may be differences between details within the definitions, such as minimum number of occupants, that could result in a different classification. NFPA 101 and 5000 Occupancy Classification IBC Occupancy Classification Assembly Assembly (divided into subcategories A-1, A-2, A-3, A-4, A-5) Ambulatory Health Care Business Educational Educational Day Care Educational or Institutional Health Care Institutional (divided into subcategories I-1, I-2, I-3, and I-4) Detention and Correctional Residential Board and Care Institutional or Residential One- and Two-Family Dwelling Residential (divided into subcategories R-1, R-2, R-3 and R-4) Lodging or Rooming House Hotels and Dormitory Apartment Mercantile Mercantile Business Business Industrial Factory and Industrial (divided into subcategories F-1 and F-2) Storage Storage (divided into subcategories S-1 and S-2) No equivalent occupancy classification (see paragraph below for additional information) High Hazard (divided into subcategories H-1, H-2, H-3, H-4, and H-5) No equivalent occupancy classification (see paragraph below for additional information) Utility and Miscellaneous   Ambulatory Health Care One major difference between the NFPA 101/5000 occupancy classifications and the IBC classifications is the ambulatory health care occupancy classification. It is important to understand what types of facilities we are discussing before we get into how these are classified differently. Ambulatory health care occupancies per the Life Safety Code are those occupancies in which four or more patients are being treated simultaneously and are incapable of self-preservation because of (1) the treatment; (2) anesthesia; or (3) the nature of the injury/illness. Although not a separate occupancy classification, the IBC does have a definition for “Ambulatory Care Facility” which closely resembles the NFPA ambulatory health care occupancy. Per the IBC, these types of facilities would be considered business occupancies. NFPA 101 and 5000 create a distinction between business occupancies and ambulatory health care facilities based on the occupants’ ability of self-preservation. Therefore, these types of facilities would not be considered business occupancies but would be considered ambulatory health care occupancies per NFPA. It is worth mentioning that per NFPA a traditional doctor’s office or an urgent care center where patients are still capable of self-preservation would be considered business occupancies. Educational and Day Care NFPA 101 separates day care occupancies from educational occupancies. The NFPA and IBC definitions for educational occupancies are fairly similar. At first glance it may seem like some occupancies that would be classified as educational per the IBC would actually be day care occupancies per NFPA. However, when you look more closely at Chapter 16 and 17 of NFPA 101 you find that occupancies in which the primary purpose is education for children 30 months of age or older must comply with the educational occupancy requirements. It should be noted that prior to the 2021 Edition, the age was 24 months. While the educational definitions are closely aligned between NFPA and IBC, the major difference is the NFPA occupancy classification of day care. There are two main categories of day cares, those providing services for children and those providing services for adults. Instead of calling these day care occupancies, the IBC would classify child day cares serving children under two and a half years old and adult day cares as institutional occupancies. There is one exception to this. A childcare facility with more than 5 but less than 100 clients two and a half years of age or younger, and located on the level of exit discharge, is classified as an educational occupancy per the IBC. Institutional The institutional occupancy group in the IBC consists of four different categories: I-1, I-2, I-3, and I-4. These subcategories are based on anticipated occupant characteristics and there are similar occupancy classifications found in NFPA 101/5000. However, in the NPFA codes and standards these are treated as individual occupancy classifications and not as subcategories of a broader classification. Even with the sub-categories, the occupancy classifications do not always obviously align between NFPA and IBC. The table below summarize how the NFPA occupancy classifications would most likely fall into the IBC institutional subcategories.   Closer Look at how NFPA Occupancy Classifications Align with IBC Residential Subcategories NFPA IBC Notes Day Care I-4 Depends on number of occupants, age of occupants, and location of occupants in relationship to the level of exit discharge Educational Health Care   I-2 N/A Detention and Correctional I-3 N/A Residential Board and Care I-1 Depends on the number of occupants   R-3 R-4 When starting with the IBC institutional subclassification determining the NFPA occupancy classification is more straightforward. Remember though, it is important to always verify the actual definitions and minimum number of occupant requirements before selecting the appropriate occupancy classification. The table below shows the potential NFPA occupancy based on the IBC institutional subcategory.   IBC NFPA I-1 Residential Board and Care I-2 Health Care I-3 Detention and Correctional I-4 Day Care Residential The residential occupancy group in the IBC consists of four different categories: R-1, R-2, R-3, and R-4. These subcategories are based on anticipated occupant characteristics and there are similar occupancy classifications found in NFPA 101/5000. However, in the NPFA codes and standards these are treated as individual occupancy classifications and not as subcategories of a broader classification. Even with the sub-categories, the occupancy classifications do not always obviously align between NFPA and IBC. The table below summarize how the NFPA occupancy classifications would most likely fall into the IBC residential subcategories.   Closer Look at how NFPA Occupancy Classifications Align with IBC Residential Subcategories NFPA IBC Notes One- and Two-Family Dwelling R-3 N/A Lodging or Rooming House R-1 Depends on the number of occupants R-3 Hotels R-1 Depends on the nature of the occupants (transient or not) R-2 Dormitories R-2 N/A Apartment R-2 N/A Residential Board and Care R-3 Depends on the number of occupants   R-4 Institutional If you are starting with the IBC residential subclassification and trying to determine the NFPA occupancy classification, it is not as straightforward. The IBC uses terminology not found in NFPA 101 or 5000 and creates the subclassification groups based on different characteristics of how the space is being used, such as the number of occupants. The table below shows how many potential NFPA occupancies you could have per each IBC residential subcategory.   Closer Look at how IBC Residential Subcategories Align with NFPA Occupancy Classifications IBC NFPA Notes R-1 Lodging or Rooming House Depends on the number of occupants Hotel R-2 Apartment Depends on the nature of the occupants (transient or not) Hotels Dormitories R-3 One- and Two- Family Dwelling Depends on (1) number of occupants and/or outsiders and (2) if residents are receiving personal care services Lodging or Rooming House Residential Board and Care R-4 Residential Board and Care N/A High Hazard One of the major differences between how NFPA 101/5000 and the IBC address occupancy classification is how they handle areas and spaces where high hazard materials are present. The IBC has a separate occupancy classification for areas or spaces that manufacture, process, generate, or store “materials that constitute a physical or health hazard” in amounts larger than what is permitted in control areas. NFPA, on the other hand, does not create a separate occupancy classification, instead, there are provisions for high hazard contents that must be followed, regardless of the occupancy whenever applicable. High hazard contents are “those that are likely to burn with extreme rapidity or from which explosions are likely.” Additionally, there are subclassifications of certain occupancies, such as storage and industrial, for those that store or use high-hazard contents. Within the occupancy chapter, additional requirements apply based on the high-hazard classification. NFPA 5000 has a chapter with additional requirements based on the presence of high hazard contents. Again, this does not change the occupancy classification itself but does require additional fire protection and/or life safety features because of the increased hazard of the space. Utility and Miscellaneous Another major difference between how NFPA 101/5000 and the IBC address occupancy classification is the Utility and Miscellaneous occupancy classification the IBC has. There is no equivalent in the NFPA occupancy classification. In the IBC, this group is used for structures such as barns, sheds, and towers. While there is no separate occupancy group for these in the NFPA classifications, these structures would still be assigned an occupancy classification. Depending how the space is actually used, storage, industrial, or business are potential examples of appropriate occupancy classifications. Additionally, NFPA 101 and 5000 have requirements for “Special Construction” and “High-Rise” buildings. Instead of changing the occupancy classification when traditional occupancies are placed in unique buildings or are in unusual surroundings, there are requirements that modify the base occupancy requirements to accommodate for these unusual surroundings or structures and the risks associated with them. Conclusion The application of occupancy classifications between different organizations’ codes and standards is not always straight forward. Therefore, when working with multiple codes, you must consider the specific building and the occupant characteristics of that space. Since different occupant thresholds and occupant characteristics are used for different organizations’ codes and standards, you can’t always generalize how the occupancy classifications align. Hopefully, the above tables provided some insight and at least a starting point when trying to determine how the occupancy classifications relate.

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