AUTHOR: Valerie Ziavras

Accessible Means of Egress and the Life Safety Code

From 1927 until 1963, what is now NFPA 101®, Life Safety Code®, was called the Building Exits Code. Although it now covers a variety of topics, there is still a large focus on the means of egress within NFPA 101. For upper stories, we often think of exit stair enclosures as the primary exit option. But what about people with mobility impairments, such as those who use a wheelchair? How does the Life Safety Code protect people with mobility challenges? The Life Safety Code is not intended to be an accessibility code; however, there are some accessibility requirements for new buildings that have areas accessible to people with severe mobility impairments. Generally speaking, these buildings would require at least two accessible means of egress unless one of the conditions for a single means of egress can be satisfied.   What is an “accessible means of egress”?   An accessible means of egress is defined as a means of egress that provides a path to an area of refuge, a horizontal exit, or a public way. The path must comply with NFPA 101 and ICC A117.1, Accessible and Usable Buildings and Facilities. While the definition is very specific as to what constitutes an accessible means of egress, a designer still has the choice in how to satisfy the need for accessible means of egress.   Access to a public way   Accessible means of egress in single-story buildings tend to be easier to provide. A door with a path to the public way could be considered an accessible means of egress. If there are elevation changes, providing ramps instead of, or in addition to, stairs ensures the path remains accessible. In the image below, a single-story building utilizes ramps to accomplish the elevation change between the building and the public way.     However, ramps or direct access to the public way are not always viable options. The code also allows for the use of a horizontal exit or an area of refuge.   What is a “horizontal exit”?   A horizontal exit is defined as “a way of passage from one building to an area of refuge in another building on approximately the same level, or a way of passage through or around a fire barrier to an area of refuge on approximately the same level in the same building that affords safety from fire and smoke originating from the area of incidence and areas communicating therewith.” A horizontal exit uses fire-rated construction to separate occupants from the dangers associated with fire. Because fire-rated construction is used, there is often no need for an elevation change. A horizontal exit could be located in the middle of a story allowing an occupant to simply travel through a fire door in a fire-rated wall. There are a number of other criteria outlined in 7.2.4 of the 2021 edition of NFPA 101 that need to be met in order for something to be considered a horizontal exit. The image below shows an example of a horizontal exit that could serve as an accessible means of egress. The red wall would have a 2-hour fire-resistance rating and the door opening would need to be protected appropriately.     What is an “area of refuge”?   An area of refuge is defined as “either (1) a story in a building where the building is protected throughout by an approved, supervised automatic sprinkler system and has not less than two accessible rooms or spaces separated from each other by smoke-resisting partitions; or (2) a space located in a path of travel leading to a public way that is protected from the effects of fire, either by means of separation from other spaces in the same building or by virtue of location, thereby permitting a delay in egress travel from any level.” There are a number of ways to meet this, so be on the lookout for my next blog, which will discuss the different options for areas of refuge.   While NFPA 101 is not an accessibility code, it is necessary that people with disabilities have the ability to move to a safe location during a fire event or other emergency. The accessible means of egress requirements are there to ensure that happens. If you are interested in learning more about emergency evacuation planning for people with disabilities, check out this recently updated guide from NFPA.
Shoppers walk through a multi-level shopping mall

Special Provisions for Mall Structures

Even though online shopping has become the norm in today’s digital age, many people have still been inside a shopping mall. While most shoppers have probably never experienced a mall fire firsthand, a quick google search shows that mall fires are actually fairly common—not just in the United States but also across the globe.  In June, a fire broke out in the Somerset Mall in Troy, Michigan. The fire started in the kitchen of a Capital Grille. Since then, there have been a number of other fires in malls, including two in October. One occurred on the upper floor of a mall in Islamabad, Pakistan, while another occurred in exhaust ventilation ductwork in a mall in Honolulu, Hawaii. Although a number of issues were reported in the Islamabad fire, such as obstructions to the means of egress, no one was killed in either of these incidents.  So how does NFPA 101®, Life Safety Code®, work to protect occupants in malls? Well, there are provisions specific to mall structures that can be found in 36/37.4.4 of the 2021 edition of NFPA 101. What is a mall? Often, the term “mall” is unofficially used to describe several different types of structures, including strip malls, enclosed malls, or even city-like malls that span millions of square feet. The Life Safety Code has particular definitions, though, meaning a structure may be described as a “mall” but not technically considered a mall per the code. Below are some key definitions from the Life Safety Code to review before diving into the requirements. Mall structure A mall structure is defined by NFPA 101 as “a single structure enclosing a number of tenants and occupancies wherein two or more tenants or tenant buildings have a main entrance into one or more mall concourses.” The code goes on to say that “anchor buildings shall not be considered as a part of the mall structure.” That definition uses the term anchor building, which is also defined by NFPA 101.  Anchor building  An anchor building is “a building housing any occupancy having low or ordinary hazard contents and having direct access to a mall structure, but having all required means of egress independent of the mall concourse.” A good example of an anchor building would be a department store that connects to a mall but that has its own dedicated entrances/exits. Again, the code definition of an anchor building uses another term—mall concourse. So what is a mall concourse? Mall concourse According to the code, a mall concourse is “a common pedestrian area within a mall structure that serves as access for two or more tenants and does not exceed three levels that are open to each other.”  A mall concourse can be open or enclosed. In order to be considered open, one of two conditions needs to be met. The first is that at least 50 percent of the total area of the perimeter walls and roof of the concourse are open to the atmosphere. The openings need to be evenly distributed over the length of the concourse and cannot be concentrated in one particular area. The second condition is that an engineering analysis shows that the smoke layer interface is at least 6 feet (1,830 millimeters) above the highest walking level surface open to the mall concourse. That minimum 6-foot (1,830-millimeter) smoke layer interface height must be maintained for 1.5 times the calculated egress time, or 20 minutes, whichever is longer. A mall can have multiple concourses, but each of those concourses can be open to no more than three levels. If a building has a concourse that connects more than three levels, it cannot be considered a mall concourse, which means the requirements and allowances in 36/37.4.4 cannot be applied.  Protecting a mall The provisions of 36/37.4.4 are only applicable to mall structures that are three or fewer stories in height. If a building meets the definition of a mall, then a designer may choose to utilize 36/37.4.4 but is not required to. The other option would be to protect the building as a multiple occupancy building in accordance with 6.1.14. The special provisions of 36/37.4.4, however, are intended to address the common design challenges and unique features of mall structures, such as travel distance, plastic signs, kiosks, smoke control, occupant notification, and automatic sprinklers.  Let’s take a closer look at some of the select requirements for new mall structures.  Travel distance Travel distance can be a challenge in mall structures, particularly on the mall concourse. The travel distance within the tenant space must comply with the occupancy chapter; the travel distance within these spaces is measured to an exit or to the mall concourse. An additional 200 feet (61 meters) of travel for enclosed mall concourses, or 300 feet (91 meters) of travel for open concourses, is permitted provided certain criteria is met. The criteria include requirements for minimum clear width for the mall concourse, minimum widths for exits, automatic sprinklers, construction of walls between tenants, and smoke control for mall concourses connecting more than two levels.  Many malls utilize exit passageways to help them comply with the travel distance requirements. An exit passageway is a protected path of travel with strict limitations placed on what openings, penetrations, and equipment is permitted in the exit passageway. If you were to take an exit stair enclosure and rotate it 90 degrees, so instead of running vertically, it ran horizontally, you would have an exit passageway. Plastic signs Unique to malls is the number of plastic signs present. To minimize the contribution of plastic signage to fuel load and fire growth, a number of restrictions are placed on plastic signs. Plastic signs are permitted to cover no more than 20 percent of the wall area facing the mall concourse. There are also maximum sizes for signs, minimum distances between signage and adjacent tenant spaces, and restrictions on the types of materials permitted. Kiosks Another unique feature of malls is the presence of kiosks. Kiosks, whether temporary or permanent, are considered tenant spaces and must comply with several requirements. There are requirements related to the construction materials of combustible kiosks, horizontal separation distances between kiosks, or groups of kiosks, and other structures, and a maximum area of 300 square feet (27.8 square meters) for each kiosk, group of kiosks, or similar structure. Roboshields via Wikipedia  Smoke control A smoke control system is required for all new enclosed mall concourses that connect more than two stories. While a smoke control system is required, there are options in how the system is designed. It could be a completely separate mechanical exhaust system, or it could be a mechanical exhaust system in conjunction with HVAC systems. Another option would be automatically or manually released gravity roof vent devices. The designer may choose to combine any of those types of systems or could choose another engineered system. Occupant notification At any time the mall concourse is occupied, the fire alarm system, once initiated, must either activate a general alarm in accordance with 9.6.3 (positive alarm sequence is permitted) or use voice communication or a public address system in accordance with 9.6.3.10. It should be noted that visible signals are not required in mall concourses. Automatic sprinklers A supervised automatic sprinkler system is required throughout all mall structures and all anchor buildings. The sprinkler system must be capable of having any portion of the system serving tenant spaces taken out of service without affecting the operation of the portion of the system that serves the mall concourse. Any shades, canopies, awnings, or similar structures in an open mall concourse must be protected with automatic sprinklers. Kiosks or similar structures within enclosed mall concourses must be protected throughout with automatic sprinklers. Conclusion The special provisions of 36/37.4.4 are there as an option for designers to use to help address the unique features of a mall. However, it is imperative that before utilizing these requirements, designers ensure the structures do in fact meet the definitions associated with mall structures.

What are the code requirements for haunted house attractions?

A version of this blog written by Kristin Bigda, publications strategy director at NFPA, first appeared in 2016. The article has been edited to reflect more recent code editions. With Halloween quickly approaching, thoughts of candy, ghosts, and haunted houses are surely on your mind. While haunted houses may be an entertaining way to spend an October evening, there can be devastating consequences if a fire were to break out and proper protections aren’t in place. What are haunted houses and special amusement buildings? Haunted houses may be temporary in nature or permanently installed. Sometimes, they are used only near Halloween, while others may be open year-round. This was the case in the tragic Haunted Castle fire that occurred at a permanently installed, year-round haunted house located at a Six Flags amusement park in New Jersey on May 11, 1984. Eight teenagers died in that blaze.  To prevent a similar tragedy to the Six Flags haunted house fire, provisions were added to NFPA 1, Fire Code, and NFPA 101®, Life Safety Code®, to address special amusement buildings—the category in which haunted houses typically fall. According to the 2021 edition of NFPA 1, a special amusement building is “a building or portion thereof that is temporary, permanent, or mobile and contains a ride or device that conveys patrons where the patrons can be contained or restrained, or provides a walkway along, around, or over a course in any direction as a form of amusement or entertainment, and arranged so that the egress path is not readily apparent due to visual or audio distractions, contains an intentionally confounded egress path, or is not readily available due to the mode of conveyance through the building or structure.” A special amusement building is an assembly occupancy regardless of occupant load. Special amusement buildings often use special effects, scenery, props, and audio and visual distractions that may cause egress paths to become difficult to identify. In haunted houses, in particular, the presence of combustible materials and special scenery can also contribute to the fuel load and, may result in rapid fire spread should a fire occur.   “ Haunted houses use special effects, scenery, props, and audio and visual distractions that may cause egress paths to become difficult to identify What does the code say? Code provisions for special amusement buildings are found in Section 20.1.4 of NFPA 1. The code requirements for haunted houses are summarized below: Haunted houses must apply the provisions for assembly occupancies in addition to the provisions of Section 20.1.4. Automatic sprinklers are required for all haunted houses unless it is less than 10 feet (3050 millimeters) in height and has less than 160 square feet (15 square meters) of aggregate horizontal projections. If the haunted house is considered moveable or portable, an approved temporary means is permitted to be used for water supply.  Smoke detection is required throughout all haunted houses.  The actuation of any smoke detection device in a mobile or temporary haunted house must sound an alarm at a constantly attended location on the premises. A fire alarm system is required in all permanently installed haunted houses.   The fire alarm system in all permanently installed haunted houses must be initiated by required smoke detection, the required automatic sprinkler system, and manual means at a constantly attended location under continuous supervision by competent persons when the haunted house is open to patrons. Actuation of sprinklers, or any suppression systems, as well as smoke detection systems (having cross-zoning capability) must provide an increase in illumination of the means of egress and termination of other confusing visuals or sounds. The one exception is for haunted houses that are in permanently installed special amusement buildings that use a ride (or similar device) that occupants are contained in and unable to evacuate themselves without the help of a ride operator and that meet specific criteria. Exit marking and floor proximity exit signs are required. Where designs are such that the egress path is not apparent, additional directional exit marking is required. Interior wall and ceiling finish materials must be Class A throughout. Per Section 10.8.1, emergency action plans are required. Other requirements, not specific just to haunted houses or special amusement buildings, may also apply, such as:  Permits (see Section 1.12) Seasonal buildings (see Section 10.12) Special outdoor events, fairs, and carnivals (see Section 10.14) As we move into the Halloween and haunted house season, it’s easy to get caught up in the fun and overlook the safety issues that may arise. Through the provisions in NFPA 1, which can assist code officials and fire departments in enforcing safe haunted houses, and NFPA’s Halloween resources for consumers, everyone can stay safe this season.

A Closer Look at Some Assembly Occupancy Requirements

The fire at a Thai nightclub in early August 2022 was all too familiar. It started during a live music performance killing 20 people and injuring 25. Many of the details emerging are eerily similar to The Station nightclub fire which claimed the lives of 100 people and injured 230 more in February of 2003. In both instances, flammable interior finish and blocked exits were believed to have played a role in the fast-spreading fires and high number of fatalities. The 2003 tragedy led to a number of changes to NFPA 101, Life Safety Code, while also reiterating the importance of interior finish and means of egress requirements for assembly occupancies. Interior finishes are the interior surfaces of a building that are generally secured in place like wall and ceiling coverings. They have proven to be a contributing factor in how quickly a fire spreads. To minimize the impact interior finish has on fire spread, Chapter 10 of the 2021 edition NFPA 101, Life Safety Code®, establishes basic requirements for interior wall, ceiling, and floor finishes. Chapter 10 outlines two testing options: 1) testing in accordance with NFPA 286, Standard Methods of Fire Tests for Evaluating Contribution of Wall and Ceiling Interior Finish to Room Fire Growth; or 2) testing in accordance with ASTM E84 or UL 723.  Paragraph 10.2.3.1.2 of the 2021 edition of NFPA 101, outlines acceptance criteria for materials tested in accordance with NFPA 286. The acceptance criteria includes: limitations on the spread of flames; peak heat release rate less than 800 kW; and for new installations the total smoke released throughout the test cannot exceed 1000 m2. Any material that meets the criteria outlined in 10.2.3.1.2 can be used wherever a Class A material is permitted. The alternative test method (ASTM E84 or UL 723) results in the material being grouped into a class. There are three classes- Class A, Class B, and Class C which are determined by a material’s flame spread index and smoke developed index. Class A materials will have the lowest flame spread index of the three classifications. The smoke developed index is the same range for all three classifications. For newly installed materials both the flame spread index and smoke developed index is considered, whereas for existing materials only flame spread index is considered. Occupancy chapters may further regulate interior finish beyond what is contained in Chapter 10. In both fires, acoustic material is believed to have been a major contributing factor in the rapid spread of fire. Assembly occupancies do further regulate interior finish. The requirements are the same for new and existing assembly occupancies. In general assembly areas with an occupant load of 300 or fewer, ceiling and wall materials must be Class A, B, or C. In general assembly areas with an occupant load of more than 300, and in corridors, and lobbies, interior wall and ceiling finishes must be Class A or B. In enclosed stairs interior finish materials must be Class A. One other contributing factor was the availability of exits. In both the fire in Thailand and at The Station nightclub, one of the doors to the outside was blocked for use by occupants to allow the band performing to have their own separate entrance/exit. One of the fundamental components of the Life Safety Code is the concept of free egress. Prohibiting people from entering the building via a door is one thing, but not allowing occupants to exit the building via the nearest door is unacceptable. Additionally, NFPA 101 prohibits the means of egress for assembly occupancies from going through hazardous areas such as kitchens, storerooms, closets, stages, and platforms. There are also requirements related to the size of a main entrance/exit, where one exists. History has shown that occupants tend to go out the way they came, even if there is an exit closer. The main entrance/exit provisions are intended to prevent crowd crush situations. In existing assembly occupancies, the main entrance/exit needs to be sized to accommodate at least one-half the total occupant load. For new assembly occupancies that are dance halls, discotheques, nightclubs, or that have festival seating, the main entrance/exits must be wide enough to accommodate two-thirds of the total occupant load. The main entrance/exit for all other new assembly occupancies must be sized to accommodate one-half the total occupant load. If the assembly occupancy is more than one level, then each level must have access to the main entrance/exit and that access must be sized to handle two-thirds (for new assembly occupancies) or one-half (for existing) of the occupant load of that level. The main entrance/exit requirements for certain types of new assembly occupancies was increased from one-half to two-thirds the total occupant load due to a crowd crush event during The Station nightclub fire. Another way the Life Safety Code strives to reduce the risk of crowd crush is by requiring trained crowd managers. All assembly occupancies, with the exception of certain ones used exclusively for religious worship, are required to have at least one trained crowd manager. Depending on the total occupant load, additional crowd managers may be required. Typically, there should be one crowd manager for every 250 occupants. Prior to the 2006 Edition, crowd managers were only required for assembly occupancies with occupant loads of more than 1000. After The Station nightclub fire, the Life Safety Code was changed to require at least one crowd manager for all assembly occupancies. Within 2 minutes of the fire starting at The Station nightclub, there was crowd crush at the main entrance/exit. This led to the main entrance/exit being almost completely impassable. The crowd manager’s responsibilities include understanding crowd management, understanding methods of evacuation, being familiar with the facility evacuation plan, being familiar with the emergency response procedures, and understanding procedures for reporting emergencies. While the cause of the recent fire at the Thai nightclub is still under investigation, The Station nightclub fire was caused by pyrotechnics. To reduce the risk of open flames or pyrotechnics starting a fire in an assembly occupancy they are prohibited unless certain conditions are met. In order for pyrotechnics to be used on stage before proximate audiences, precautions to prevent ignition of any combustible material, satisfactory to the authority having jurisdiction must be met and the use of the pyrotechnic device must comply with NFPA 1126, Standard for the Use of Pyrotechnics Before a Proximate Audience. As we have seen countless times, fires in assembly occupancies, and in particular nightclubs, can result in a high number of fatalities. By carefully considering the use of open flames and pyrotechnics we can eliminate potential ignition sources in these types of occupancies. Additionally, ensuring the interior finish requirements for assembly occupancies are met can help slow the spread of fire. Fires in an assembly occupancy have the added risk of leading to a crowd crush event. Compliance with the means of egress and crowd manager requirements will help reduce the risk of crowd crush events during emergency situations. 
HazMat

NFPA and IBC Occupancy Classifications when Hazardous Materials are Present

Hazardous materials are those chemicals or substances that are classified as a physical hazard material or a health hazard material (see this blog for more information). There's often some confusion around what the appropriate occupancy classification is when hazardous materials are present. Unfortunately, there isn't a straight answer. It is going to depend on what code is applicable in your particular situation. This blog is going to take a closer look at the differences in occupancy classification when using NFPA Codes and the International Building Code (IBC). For some basic information regarding the differences in occupancy classification check out this blog. Before digging into the actual differences between the codes it's helpful to understand the concepts of maximum allowable quantity (MAQ) and control areas. Although NFPA Codes and the IBC both address these concepts in their own documents, the overall approach is similar. For a closer look at how to determine a MAQ using NFPA 1, Fire Code, be sure to look at this blog. NFPA Approach One of the major differences between the way the IBC and NFPA codes address occupancy classification for spaces using hazardous materials, is the actual creation of a unique occupancy classification within the IBC. NFPA codes do not create a separate occupancy classification specific to hazardous materials. Instead, regardless of whether they contain hazardous materials or not, all buildings are given an occupancy classification(s) based on how the space is being used and the expected characteristics of the occupants. Then, if the building contains hazardous materials additional provisions must be met. If the hazardous materials in a given control area exceed the MAQ, additional protections are required. These are called Protection Levels and they range from Protection Level 1 to Protection Level 5. It is important to note that although a building must comply with the additional protection levels, the occupancy classification itself does not change. This means when the MAQ is exceeded and NFPA documents apply, you are required to comply with both the requirements specific to that occupancy as well as the appropriate protection level requirements for that hazardous material. NFPA Approach- Protection Levels Features for Protection Level 1 through Protection Level 3 are intended primarily to provide protection from physical hazards. Protection Level 1 is the highest level of protection. This protection level is required when high hazard Level 1 contents exceed the MAQ. These materials are unstable and can pose a detonation hazard. Examples of high hazard level 1 contents include Class 4 oxidizers; detonable pyrophoric solids or liquids; Class 3 detonable and Class 4 unstable (reactive) solids, liquids, or gases; and detonable organic peroxides. This protection level requires that the materials be stored in a one story in height, detached building that is used for no other purpose. Protection Level 2 is designed to limit the spread of fire from materials that deflagrate or accelerate burning. Additionally, the protection features are designed to limit the potential for fire to spread from an outside source and affect the hazardous materials in the building. This protection level is required when high hazard Level 2 contents exceed the MAQ. These materials present a deflagration hazard or a hazard from accelerated burning. Examples of high hazard Level 2 contents include Combustible dusts that are stored, used, or generated in a manner that creates a severe fire or explosion hazard; Class I organic peroxides; flammable gases; nondetonable pyrophoric solids, liquids, or gases; and Class 3 water-reactive solids and liquids. Protection Level 3 is one of the most common protection levels encountered in the general inspection of storage and industrial operations that use hazardous materials. These types of operations and storage facilities normally operate with amounts of hazardous materials greater than the MAQ while conducting business. This protection level is required when high hazard Level 3 contents exceed the MAQ. These materials readily support combustion or present a physical hazard. Examples of high hazard level 3 contents include Class IIA, Class IIB, and Class III organic peroxides; Class 2 solid or liquid oxidizers; Class 2 unstable (reactive) materials; and oxidizing gases. Protection Level 4 is intended to mitigate the acute health hazards resulting from the storage, use, or handling of high hazard Level 4 materials. These contents include corrosives, highly toxic materials, and toxic materials. The objective is to protect evacuating occupants and arriving first responders from being injured by these hazardous materials. Protection Level 5 applies to semiconductor fabrication facilities. Buildings that require Protection Level 5 must comply with NFPA 318, Standard for the Protection of Semiconductor Fabrication Facilities. IBC Approach The IBC uses a High-Hazard Group H, occupancy classification for buildings that, among others, manufacture, process, generate, or store hazardous materials in excess of the MAQ in a control area. There are 5 sub-categories within the High Hazard Group H occupancy, H-1 through H-5 which closely resemble the protection levels in NFPA documents. IBC Approach- Occupancy Subclassifications H-1 is the subclassification for buildings that contain hazardous materials that pose a detonation hazard. H-2 is the subclassification for buildings that contain hazardous materials that pose a deflagration hazard or a hazard from accelerated burning. H-3 is the subclassification for buildings that contain hazardous materials that readily support combustion or that pose a physical hazard. H-4 is the subclassification for buildings that contain hazardous materials that are health hazards. H-5 is the subclassification for semiconductor fabrication facilities and comparable research and development areas. Although at first glance it seems like NFPA and the IBC handle things extremely different, the overall concepts are actually not all that different. The IBC creates an entirely separate occupancy classification while NFPA uses protection levels. In both cases, compliance with additional provisions is going to be required to minimize the risk associated with the presence of hazardous materials in those quantities.  
HazMat

Determining the Maximum Allowable Quantity (MAQ) of a 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, 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? This blog will focus on determining the maximum allowable quantity (MAQ) for a hazardous material per NFPA 1, Fire Code and NFPA 400, Hazardous Materials Code. The eight-step process outlined here, is just one way to determine the MAQ. Step 1: Determine hazardous material classification The first step in identifying the Maximum Allowable Quantity (MAQ) is to determine the category of the hazardous material. NFPA 400 divides hazardous materials into 14 different categories. Using the definitions within the Code, the category or categories of the material must be determined. A hazardous material may fall into more than one category. It is also important to acknowledge that there are additional types of hazardous materials that fall outside the scope of what is intended to be covered by NFPA 400 and thus Chapter 60 of NFPA 1. This includes things like: Flammable and combustible liquids that have no other health hazard covered by NFPA 400 (instead see NFPA 30) LP-gas storage or utilization systems (instead see NFPA 58 or NFPA 59) Storage and use of aerosol products (instead see NFPA 30B) For additional information related to classifying a hazardous material, check out this blog. Step 2: Determine occupancy classification Next, we need to determine the occupancy classification of the area where the hazardous material is going to be stored or used. Different occupancies modify the MAQs so, once we determine the MAQ per the general MAQ table (Table 60.4.2.1.1.3 of the 2021 Edition of NFPA 1), we will need to consult the other appropriate paragraphs (60.4.2.1.2 through 60.4.2.1.5) to see if that quantity is modified in any way. An excerpt of the general MAQ table can be seen below in step 4. Step 3: Determine how the material will be used The next variable that needs to be determined is based on how the material is going to be used. There are two main ways the material could be used. It could be stored, or it could actually be used. The storage use is intended for those instances where a hazardous material is entering the building in a container, cylinder, or tank and will not be removed from the original container, cylinder, or tank. If the hazardous material is being used, you must then identify whether it is being used in a closed system or an open system. A closed use system designation means that, under normal conditions, the hazardous material will not be open to the atmosphere and will be kept within a container, a pipe, or equipment that does not allow vapors to escape into the air. Closed use and storage have very similar risks and are treated the same with respect to MAQ. An open use system designation means that the process involves pouring or dispensing into an open vessel, open mixing, transferring, or processing of a hazardous material that is exposed to the atmosphere. This type of activity is considered the most hazardous and, therefore, is most restricted with respect to an MAQ. Step 4: Determine base maximum allowable quantity The next step is to determine the MAQ. The term "maximum" can be misleading because there are certain conditions that would allow higher amounts of material to be used or stored. The term "MAQ" really means the maximum amount of a material that is permitted in a control area before requiring additional protection. So, it's not really a "maximum", rather a threshold before additional protection requirements would need to be applied. NFPA 1, the Fire Code, has a couple different MAQ tables which are copied from NFPA 400. The applicable table will depend on the occupancy you are in. Generally speaking, you would start with the general MAQ table (Table 60.4.2.1.1.3) and then see if/how the occupancy specific sections modify the table. In the case of a laboratory that is a business office, the code states you are to use the amounts from Table 60.4.2.1.1.3 without using the modifications found in 60.4.2.1.2. In order to best explain how the table and associated footnotes work, we will walk through an example. The space is used as a laboratory but is considered a business occupancy. There are two different hazardous materials. One is classified as an organic peroxide class I and will only be stored. The other will be used in an open system and is classified as water-reactive class 2. Organic Peroxide Class I Using the table, the MAQ for an organic peroxide class I that is to be stored as a solid is 16 lbs (7.26 kg). However, looking at the table there are two applicable footnotes. Applying these footnotes is explained in the next step. Water Reactive Class 2 Using the table, the MAQ for a water reactive class 2 material that is to be used in an open system is 10 lbs (4.54 kg). However, looking at the table there is one applicable footnote. Applying this footnote is explained in the next step Step 5: Apply footnotes Once the base MAQ is determined from the table, adjustments to the MAQ should be made based on the applicable footnotes. Returning to our example: Organic Peroxide Class I Per the table 16 solid lbs (7.26 kg) of a class I organic peroxide are permitted. However, footnote a allows 100% increase where the hazardous material is stored in an approved cabinet, gas cabinet, exhausted enclosure, gas rooms explosive magazines, or safety cans, as appropriate for the material stored. The second footnote, b, allows for a 100% increase if the building is equipped throughout with an automatic sprinkler system. These increases can be used in conjunction with each other as noted in the footnotes. This means the MAQ will depend on what additional features are provided. If the material is not stored in an approved cabinet or similar container and there is no sprinkler system, then the 16 lbs (7.26 kg) from the table stands as the MAQ. If the material is going to be stored in an approved cabinet or other similar container, but the building is not sprinklered then the MAQ is 32 lbs (14.54 kg). 16+(16×1)=32 lbs 7.26+(7.26*1)=14.52 kg This would also be the MAQ if the building was sprinklered but the material wasn't going to be stored in an approved cabinet or other similar container. If the material will be stored in an approved cabinet or other similar container and is in a building equipped with an automatic sprinkler system, then the MAQ is 64 lbs. The original MAQ is 16 lbs (14.52 kg). This is allowed to be increased by 100% because of the use of an approved cabinet: 16+(16×1)=32 lbs 7.26+(7.26*1)=14.52 kg Then that new MAQ, 32 lbs (14.52 kg) is permitted to be increased by 100% because the building is protected throughout with an automatic sprinkler system. This results in an MAQ of 64 lbs (29.04 kg): 32+(32×1)=64 lbs 14.52+(14.52*1)=29.04 kg Water Reactive Class 2 Per the table 10 solid lbs (4.54 kg) of a class 2 water reactive material is permitted. There is only one applicable footnote which allows a 100% increase if the building is equipped with an automatic sprinkler system. In this case if the building has a sprinkler system the MAQ would be 20 lbs (9.08 kg): 10+(10×1)=20 lbs 4.54+(4.54×1)=9.08 kg If the building does not have a sprinkler system, then the MAQ remains 10 lbs (4.54 kg). Step 6: Adjust Based on Control Area Location As I mentioned earlier, the term "MAQ" really means the maximum amount of a material that is permitted in a control area before requiring additional protection. A control area is a building or portion of a building or outdoor area within which hazardous materials are allowed to be stored, dispensed, used, or handled in quantities not exceeding the MAQ. It is possible to have multiple control areas per floor depending on where in the building the control areas are located. The table below can be found in NFPA 1 (and NFPA 400) and dictates how many control areas are permitted per floor depending on the location within the building. This table also identifies the required fire resistance rating for the fire barriers that separate the control area from other control areas and what percentage of the MAQ is permitted based on the location within the building. It is important to note that the fire barriers are required to include floors and walls as necessary to provide complete separation. You'll notice that the further, vertically, from grade, the control area is, the higher the required fire resistance rating is for the separation of control areas and a lower percent of the MAQ is permitted in each control area. This is because the vertical distance increases the time required for emergency responders to reach the incident and increases the difficulty in controlling and resolving it. Returning to our example, the floor ceiling assembly between the 1st and 2nd floor is a fire barrier with a 1-hour fire resistance rating. Therefore, these can be considered two separate control areas. MAQ Floor 1: The MAQ for floor 1 is permitted to be 100% of the MAQ per control area. Therefore, 64 lbs ) of class I organic peroxide is permitted and 20 lbs (9.08 kg) of class 2 water reactive material is permitted. Organic peroxide class I: 64×100%=64 lbs 29.04×100%=29.04 kg Water reactive class 2: 20×100%=20 lbs 9.08×100%=9.08 kg MAQ Floor 2: The MAQ for floor 2 is permitted to be 75% of the MAQ per control area. Therefore, 48 lbs (21.78 kg) of class I organic peroxide is permitted and 15 lbs (6.81 kg) of class 2 water reactive material is permitted. Organic peroxide class I: 64×75%=48 lbs 29.04×75%=21.78 kg Water reactive class 2: 20×75%=15 lbs 9.08×75%=6.81 kg Step 7: Determine if Design is Acceptable The last step is to determine if the proposed design and amounts is acceptable based on the MAQ identified and control area location. Returning to our example, our building requires the storage of 150 lbs (68.1 kg) of class I organic peroxide and the open system use of 12 lbs (5.45 kg) of a class 2 water reactive material in both locations. To determine if our design of one control area on floor 1 and one control area on floor 2 with no additional protection is acceptable, we must compare the amounts of hazardous materials present with the MAQs.   Floor 1: Remember, the MAQs for floor 1 were 64 lbs (29.04 kg) of class I organic peroxide and 20 lbs of class 2 water reactive material. The 12 lbs (5.45 kg) of class 2 water reactive material is acceptable. However, the 150 lbs (68.1 kg) of class I organic peroxide exceeds the MAQ of 64 lbs (29.04 kg). This means a change to our design is necessary. One option is to provide additional protection (see the next step for more information on this). The other option would be to provide additional control areas on the same floor, if permitted per Table 60.4.2.2.1. It is important to remember these additional control areas would need to be separated from each other by fire barriers. In the case of the first floor up to 4 control areas containing 64 lbs (29.04 kg) of the class I organic peroxide are permitted. Therefore, adding two additional control areas and properly separating them would permit the storage of up to 192 lbs (87.17 kg). If the additional control areas are added, then the Protection Level 2 requirements need not be applied.   Floor 2: Remember, the MAQ for floor 2 were 48 lbs of class I organic peroxide and 15 lbs of class 2 water reactive material. The 12 lbs (5.45 kg) of class 2 water reactive material is acceptable. However, the 150 lbs (68.1 kg) of class I organic peroxide exceeds the MAQ of 48 lbs (21.78 kg). Again, this would require a change to our design. Looking at Table 60.4.2.2.1 we see that only 3 control areas are permitted on floor 2. This means that only a total of 144 lbs (65.38 kg) would be permitted on floor 2. Either, we need to add the fire barriers to create the additional control areas and store 6 lbs (2.72 kg) less than what was originally planned, or we need to add additional protection (see the next step for more information on this). Step 8: Apply additional protections, if necessary If the amount of hazardous material cannot be accommodated based on the number of permitted control areas and the MAQ of those control areas, then additional protection is required. There are 5 different protection levels outlined in the code ranging from Protection Level 1 to Protection Level 5.   Protection Level 1 is the highest level of protection. The only way to provide a greater level of protection is to prohibit additional hazardous materials at the site or to move the hazardous materials to a detached building. This protection level is required when high hazard Level 1 contents exceed the MAQ. These materials are unstable and can pose a detonation hazard.   Protection Level 2 is designed to limit the spread of fire from materials that deflagrate or accelerate burning. Additionally, the protection features are designed to limit the potential for fire to spread from an outside source and affect the hazardous materials in the building.   Protection Level 3 is one of the most common protection levels encountered in the general inspection of storage and industrial operations that use hazardous materials. These types of operations and storage facilities normally operate with amounts of hazardous materials greater than the MAQ while conducting business. The protection features should be understood in detail, and the amounts of hazardous materials should be reviewed due to their frequent presence within most jurisdictions. Features for   Protection Level 1 through Protection Level 3 are intended primarily to provide protection from physical hazards.   Protection Level 4 is intended to mitigate the acute health hazards resulting from the storage, use, or handling of high hazard Level 4 materials. These contents include corrosives, highly toxic materials, and toxic materials. The objective is to protect evacuating occupants and arriving first responders from being injured by these hazardous materials.   Protection Level 5 applies to semiconductor fabrication facilities.   Returning to our example, the class I organic peroxide is considered a high hazard protection level 2. Therefore, if the MAQ is to be exceeded then the requirements for Protection Level 2 must be followed. The general requirements for this (and all) protection level(s) can be found in Chapter 6 of NFPA 400. In addition to chapter 6, the appropriate chapters from 11-21 need to be consulted as well as the building code. Examples of additional requirements include required separation of occupancies, shorter travel distance limits and common path of travel limits, and more restrictive requirements relating to the number and access of means of egress. For example, the travel distance limitation for a Protection Level 2 area is 100 ft and the common path of travel is 25 feet. These would generally be more restrictive than what the building code or life safety code would say for a business occupancy. In addition to chapter 6, chapter 14 would need to be reviewed as it has requirements for organic peroxide and the building code. Conclusion This 8-step process is just one way to approach determining the MAQ. It is important to remember that they type of hazardous material, whether the material is going to be stored or used, the occupancy classification, and the location of the control area all impact the MAQ. This means that any proposed change to the material, or the location of the material should be carefully evaluated to ensure quantities still fall below the MAQ, or the necessary additional protection requirements are met. If you are looking for more information on classifying a hazardous material or the applicability of NFPA 400 be sure to check out my other blogs. 
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