Topic: Code Enforcement

Commodity Classifications in NFPA 13

Commodity classifications are used to categorize the contents of storage occupancies so that the appropriate sprinkler system design can be identified. Commodity classifications are determined by not only the product but also the packaging of that product, the container those packaged products are in, and even the pallet type. This can get a little complicated, so I’ll run through a quick example. We have glass jars stored in a double layered carboard box with cardboard dividers and it is sitting on a reinforced plastic pallet. Even though the glass jars are only a Class I commodity, the cardboard box and plastic pallet increases the fuel load so that it should be considered a Class IV. Commodity Classifications are broken down into Classes I through IV and Group A though C plastics with Class I being the lowest hazard level and Group A expanded plastics being the highest hazard level. Class I: A Class I commodity is defined as a noncombustible product that meets one of the following criteria: Placed directly on wood pallets Placed in single-layer corrugated cardboard boxes, with or without single-thickness cardboard dividers Shrink-wrapped or paper-wrapped as a unit load Class II: A Class II commodity is defined as a noncombustible product that is in slatted wooden crates, solid wood boxes, multiple-layered corrugated cardboard box, or equivalent combustible packaging material. Class III: A Class III commodity is defined as a product fashioned from wood, paper, natural fibers, or Group C plastics with or without cartons, boxes, or crates. A Class III commodity shall be permitted to contain a limited amount (5 percent or less by weight of nonexpanded plastic or 5 percent or less by volume of expanded plastic) of Group A or Group B plastics. Class IV: A Class IV commodity is defined as a product that meets one of the following criteria: Constructed partially or totally of Group B plastics Consists of free-flowing Group A plastic materials Cartoned, or within a wooden container, that contains greater than 5 percent and up to 15 percent by weight of Group A nonexpanded plastic Cartoned, or within a wooden container, that contains greater than 5 percent and up to 25 percent by volume of expanded Group A plastics Cartoned, or within a wooden container, that contains a mix of Group A expanded and nonexpanded plastics and complies with the graph section at the end of the blog Exposed, that contains greater than 5 percent and up to 15 percent by weight of Group A nonexpanded plastic Exposed, that contains a mix of Group A expanded and nonexpanded plastics and complies with the graph section at the end of the blog PLASTICS Plastics are a little more straightforward since there is a specific list of what each group contains. Classifying plastics gets complicated when the commodity being stored is a combination of different groups of plastics, but the graphs at the end of this blog should be able to help alleviate some of that work. Group C Plastics: Group C plastics are treated as Class III Commodities and consist of the following: Fluoroplastics (PCTFE — polychlorotrifluoroethylene; PTFE — polytetrafluoroethylene) Melamine (melamine formaldehyde) Phenolic PVC (polyvinyl chloride — flexible — PVCs with plasticizer content up to 20 percent) PVDC (polyvinylidene chloride) PVDF (polyvinylidene fluoride) Urea (urea formaldehyde) Group B Plastics: Group B plastics are treated as Class IV Commodities and consist of the following: Chloroprene rubber Fluoroplastics (ECTFE — ethylene-chlorotrifluoro-ethylene copolymer; ETFE — ethylene-tetrafluoroethylene-copolymer; FEP — fluorinated ethylene-propylene copolymer) Silicone rubber Group A Plastic: Group A plastics are further subdivided into expanded and nonexpanded Group A plastics and consist of all of the plastics listed in the table below. ABS (acrylonitrile-butadiene-styrene copolymer) FRP (fiberglass-reinforced polyester) Polycarbonate PVC (polyvinyl chloride — highly plasticized, with plasticizer content greater than 20 percent) (rarely found) Acetal (polyformaldehyde) Natural rubber Polyester elastomer Acrylic (polymethyl methacrylate) Nitrile-rubber (acrylonitrile-butadiene-rubber) Polyethylene Butyl rubber Nylon (nylon 6, nylon 6/6) Polypropylene PVF (polyvinyl fluoride) Cellulosics (cellulose acetate, cellulose acetate butyrate, ethyl cellulose) PET (thermoplastic polyester) Polystyrene SAN (styrene acrylonitrile) EPDM (ethylene-propylene rubber) Polybutadiene Polyurethane SBR (styrene-butadiene rubber) HELPFUL DEFINITIONS One of the biggest issues I see when people are starting to learn about sprinkler design for storage occupancies is that they don’t know the terminology. It is important to fully understand the definitions for the terms used in the storage chapters of NFPA 13, Standard for the Installation of Sprinkler Systems. I recommend looking at the definition chapter of NFPA 13 to make sure you understand exactly what a term means because oftentimes it means something different than what you would expect. Here are a couple of definitions that are important to understanding this blog. Expanded Group A Plastics: Those plastics, the density of which is reduced by the presence of air pockets dispersed throughout their mass. Some examples include packing peanuts or acoustic foam. Nonexpanded is everything else that is not covered under the definition of expanded. Free Flowing Group A Plastics (protect as Class IV): Those plastics that fall out of their containers during a fire, fill flue spaces, and create a smothering effect on the fire. Examples include powder, pellets, flakes or random-packed small objects. Free flowing plastics are those small objects that fill a box or a subdivision within the box without restraint. The theory is that during a fire. The objects will freely fall out of the box and either smother the fire or fall away from it, removing themselves as fuel. Since the burning rate is reduced and fuel load has been lessened, free-flowing plastics are permitted to be treated as a Class IV commodity. Exposed: Commodities not in packaging or coverings that absorb water. For example, a cardboard box or wooden container can both absorb water so they would not be considered exposed. However, something that is wrapped in plastic sheeting could be considered exposed since plastic sheeting doesn’t absorb water. Cartoned - A method of storage consisting of corrugated cardboard or paperboard containers fully enclosing the commodity. GRAPHS The following tables come from NFPA 13 to help with navigating how a commodity should be classified when it contains Group A plastics. Note that the X axis is percentage by volume while the Y axis is percentage be weight.  The first graph addresses exposed commodities while the second graph addresses commodities that are cartoned or within a wooden container (non-exposed). PALLETS When commodities are tested, they are tested on wooden pallets. This means that wooden pallets are assumed to be used in commodity classifications, however if plastic pallets are used, they increase the commodity classification by two classes. Although, if the plastic pallet is made of polypropylene or high-density polyethylene and marked as “nonreinforced” then the commodity classification only needs to be increased by one classification. Plastic Pallet Increase (+2) Class I --> Class III Class II --> Class IV Class III --> Group A Plastics Class IV --> Cartoned nonexpanded Group A plastic Group A Plastics --> Group A Plastics (No increase)  Unreinforced Polypropylene or High-Density Polyethylene Plastic Pallet Increase (+1) Class I --> Class II Class II --> Class III Class III --> Class IV Class IV --> Cartoned nonexpanded Group A plastic Group A Plastics --> Group A Plastics (No increase) Determining the classification for commodities in storage occupancies can get complicated at times but I can not stress how important of a step this is during the sprinkler design process. It is also imperative that the owner understands what the building is designed to handle as well as what can and can not be stored in the facility once it is built. I hope you enjoyed the blog. Comment below if you have questions and be sure to share this with friends and colleagues who might find it helpful.
Highrise buildings through the clouds

Egress Challenges Related to Assembly Spaces Located at the Top of High Rise Buildings

The best views of the urban landscape are often from the top floors of the area's high rise buildings. This real estate has become sought after for restaurants, multi purpose rooms, large corporate meeting areas and even tourist attractions. Assembly spaces such as these, located on the top floors of high rise buildings combine the hazards of high occupant density with the egress concerns of high rise buildings, creating challenges in egress design as well as facility operators. This blog will review how NFPA 101, Life Safety Code provides guidance on mitigating these challenges effectively.  What is an assembly space? When 50 or more individuals can gather in a space for uses such as entertainment, eating, drinking, or deliberation, the area is considered an assembly occupancy. This type of use may involve dense occupant loads, ten times that of a business occupancy and more than ten times as dense as residential occupancies. The occupants of assembly spaces are often first-time visitors who are unfamiliar with the location and availability of egress. When is a building considered a high rise? Any building containing an occupied floor which is more than 75ft above the lowest level of fire department vehicle access, would be considered a high rise building. The 75 ft value corresponds with the highest level most common fire department aerial apparatus can reach. Total evacuation of these buildings can take anywhere from tens of minutes to hours depending on their size. Design considerations In the United States, new high rise buildings must incorporate fire protection of the structural elements. This is typically accomplished with the use of non-combustible or limited combustible construction (Type I & Type II). The building must also be protected throughout with an approved automatic fire sprinkler system, class I standpipe system and voice communications fire alarm system. All vertical exit enclosures in high rise buildings must be designed as smoke proof enclosures. Additionally, the entire building requires emergency/standby power as well as an emergency command center.  In the case of an assembly space, located on the top floor of a high rise building, the occupant load of the assembly space will drive the means of egress requirements for the entire building. The table below shows how the number of required exits increases as the occupant load increases. Even a medium size assembly dining room or bar may require three exits, which continue to the level of exit discharge. This can take up valuable real estate in the building all the way to the ground floor as shown in the building section below. Table 1: Minimum Number of Exist (NFPA 101 7.4) Number of Occupants Minimum Number of Exits <500 2 500-1000 3 1000> 4     Figure 1: Minimum number of exits example (NFPA 101 Handbook) Depending on the type of assembly space, the main entrance/exit may need to be sized to accommodate ½, or even ⅔rds of the occupant load. After considering the number of exits, exit sizing, and the need for exit remoteness (required distance between exits) the inclusion of the assembly space on the upper floors can drastically impact the egress requirements. Although elevators may not count as a means of egress, consideration may be given to their use in evacuating occupants in immediate danger. The design of the elevator enclosure as well as system functions may depend on if this use is by emergency personnel, staff or building occupants. Facility operators considerations Once a building is constructed and occupied, the facility management team is often tasked with ensuring an adequate level of safety is maintained. For assembly spaces in high rise buildings good facility management involves a comprehensive emergency action plan (EAP). At a minimum this includes how emergencies are reported, the response to emergencies by staff and occupants, and the evacuation procedures for all types of emergencies. Emergencies may be detected automatically, in the case of a fire event, or may be reported to or witnessed by staff, which is often the case in medical emergencies. The EAP will detail the response including if/when first responders are notified and how staff shall direct occupants. Should evacuation be necessary the EAP provides guidance on when zoned evacuation is appropriate, where occupants are directed away from an emergency to lower floors, or if a full building evacuation is necessary. If equipped with elevators designed for evacuation, the EAP will recommend when their use is appropriate. For more complex incidents the emergency command center will be staffed to provide additional resources and command/control. Due to the complex nature of the EAP, regular drills for all types of emergencies are required to ensure proficiency.         In existing high rise buildings, the addition of assembly space may be possible if the Authority Having Jurisdiction (AHJ) is willing to establish a maximum occupant load based on the capacity of the means of egress. It is often the facility management team's responsibility to ensure the occupant load is kept below that level for any events conducted in the space and that appropriate egress is maintained. Summary The combination of densely packed occupants, unfamiliar with their egress, located above the level of fire department aerial apparatus in buildings which may take over an hour to fully evacuate present challenges for both designers and facility managers. The Life Safety Code requires many features which increase the level of safety in these occupancies. When these requirements are combined with good facility operations practices, assembly spaces at the top of high rise buildings can safely provide breathtaking views for occupants to enjoy.
A building

Fire Sprinkler Considerations for Podium Construction

Podium, or pedestal, construction is a popular construction method that typically includes multiple stories of light wood framing over a single- or multiple-story podium of another, more fire-resistant, construction style which will often include retail or commercial space as well as parking levels. Often this is seen as Type V construction over Type I construction. This approach is used across the country and is most often utilized where the upper stories are residential occupancies. While there are certainly a number of fire protection and life safety issues to be addressed in these building types, for the purpose of this discussion we’ll focus specifically on the application of sprinkler protection for this construction type and particularly around where the use of NFPA 13R, Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies, is permitted in lieu of NFPA 13, Standard for the Installation of Sprinkler Systems.  What’s the difference between NFPA 13 and 13R? Assuming sprinkler protection is required; which for most buildings constructed in this manner building size, height, and occupancy will typically require it; a key decision point is determining if NFPA 13 is needed or if NFPA 13R can be used. The primary philosophical difference between the two is that NFPA 13 has a dual purpose of property protection and life safety while NFPA 13R has the purpose of providing life safety. The video below explains some of this difference.     While the difference might seem subtle there can be a great deal of savings based on the allowances of NFPA 13R. A major perceived benefit in using 13R can be the omission of sprinklers in areas that NFPA 13 requires sprinklers including small closets, concealed spaces, and attic spaces. These attic sprinklers are where a lot of complexity can come in since they will often require a dry system, or at least some other form of freeze protection, resulting in increased up-front costs and more long-term testing and maintenance considerations. NFPA 13R systems can also result in decreased water demands and therefore result in smaller pipe diameters. A very good analysis of the differences between NFPA 13, NFPA 13R, and NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes can be found here.  Where can NFPA 13R be used in podium construction? The podium portion of the building will need to be protected by an NFPA 13 sprinkler system. Where 3-hour separation is provided at the top of the podium as required by building codes, the upper residential portion can then be evaluated as whether it is within the scope of NFPA 13R. This includes residential occupancies that are up to and including 4 stories in height and located in buildings not exceeding 60 ft (18 m) in height above grade. If it falls within this criteria, then NFPA 13R can be utilized for the protection. While the maximum building height above grade is fixed based on the definition of height above grade, the stories themselves can be counted from the 3-hour horizontal separation. The figure below demonstrates the differences in this criteria. It is important to note that the 2021 edition of the International Building Code limits the allowance of NFPA 13R where the limitation is four stories above grade plane. This is a significant change that impacts the application of the standard. A more in-depth analysis on this can be found here.  Still a design decision Even if 13R is permitted, nothing would prohibit the use of NFPA 13 to provide added property protection required by that standard. In fact, there are building code trade-offs that can only be used with NFPA 13 systems; and the ability to take advantage of those is not available when NFPA 13R is used. Even where that is not the case, there are cost benefits but it is important to understand the goals of NFPA 13R. While a fire in a living space should be controlled as it would be with a NFPA 13 system, a fire originating in a concealed space or in an unsprinklered attic can result in the loss of the building. If all occupants are able to safely evacuate, the system has done its job even if the building is a complete loss, whereas an NFPA 13 system should be able to protect the occupants and provide property protection.
Rock climber

A Better Understanding of NFPA 70E: Your Risk Tolerance

NFPA 70E®, Standard for Electrical Safety in the Workplace® changed from an arc-flash hazard analysis to an arc-flash risk assessment several editions ago. Users are still having issues with the change. The most common complaint is that risk should not be a consideration when considering the electrical hazards an employee might be exposed to. Many want the standard to provide an absolute solution to what the employer should do to protect their employees. They don’t want to have to decide what to do, they want to be told what to do. They can apply the current that way if they wish. Others want guidance which is what the current edition provides. It allows for more leeway in determining the course of action to be taken for a given task on a piece of specific equipment. The hazard analysis determined the flash boundary, the incident energy at the working distance, and the personal protective equipment (PPE) necessary. The risk assessment first determines if an arc-flash hazard exists. If the hazard exists, the risk assessment then determines appropriate safety-related work practices, arc flash boundary and PPE to be used. Both methods require that the worst-case condition be labeled on the equipment to provide appropriate warning of the hazard lurking inside regardless of the assigned task. There is not much of a difference between the two except for determining if an arc flash hazard exists for a specific task. Imagine a battery system in a room with two terminals of the dc system in another room. If the conductors from the battery system are shorted together there is a potential for an arc-flash with an incident energy of 42 cal/cm2. However, that energy level only exists if the two conductors are shorted together. The positive conductors are brought into the terminal room on the left side and the negative conductors are brought in on the right. Those two covered terminals are separated by 12 feet. The first component after the terminals is an overcurrent device which lowers the incident energy to 14 cal/cm2. The entry to room is correctly labeled to require a 42 cal/cm2 arc-rated suit as the worst-case condition regardless of the task to be performed. Under the old system, at least a 42 cal/cm2 suit would have to be worn every time someone enters the room. Under the current method, when does the 42 cal/cm2 arc-flash hazard exist? The full amount of incident energy is always present in the room. The arc-flash hazard might exist if there is way to connect the two conductors. A task that involves pulling conductors around the room, using tools with a long span, or having conductive fluid present may exposure a worker to the full incident energy. Employee error while in the room may warrant concern. Under a risk assessment for the assigned task, you might determine that it is not possible for a worker to connect ahead of both overcurrent device terminals based on the assigned task. Would you let an employee enter that room wearing 14 cal/cm2 rated gear to perform the assigned task? If you believe that a risk assessment should not be part of the standard, you are not required to accept any risk. The risk assessment method allows you to decide that the worst-case incident energy always presents an arc-flash hazard regardless of the task performed on the equipment. If you can accept that a twelve-foot span cannot be bridged by the employee based on all possible factors, you might permit something different for the task. There are many things that might affect your acceptance of some risk instead of having a zero-risk tolerance. Regardless of your risk-tolerance, remember that it is the employee’s well-being that is wagered on your decision. NFPA 70E is available on NFPA LiNK™, the association’s information delivery platform with NFPA codes and standards, supplementary content, and visual aids for building, electrical, and life safety professionals and practitioners. Learn more at nfpa.org/LiNK.

Standpipe System Design and Calculations

Standpipe systems consist of piping and hose connections installed throughout a building to provide reliable water for the manual suppression of a fire by either the fire department or trained personnel. NFPA 14, Standard for the Installation of Standpipe and Hose Systems, Chapter 6, outlines design and installation requirements for standpipe and hose systems. Standpipe systems can be broken down into different types of systems to delineate whether the piping is full of water (wet) or not (dry) and whether the water supplied for firefighting is automatically provided by a water supply, such as a city main or a tank and fire pump (automatic or semi-automatic), or needs to be provided by a fire department pumper (manual). When designing a system, you first need to determine the supply pipe size, hose connection location, size, and pressure based on the standpipe classification. There are three classes of standpipe systems, they include Class I, Class II, and Class II. Class I Class I systems are installed for use by the fire department and are typically required in buildings that have more than three stories above or below grade because of the time and difficulty involved in laying hose from fire apparatus directly to remote floors. Class I systems are also sometimes required in malls, because these occupancies contain areas that are difficult to access directly with hose from fire apparatus. Locations for hose connections in Class I systems include: Each main floor landing or intermediate landing of required stairs. On the roof if the stairwell does not have access to the roof. Each side of exit openings in horizontal exits. Exit passageways. Additional hose connections should be available in unsprinklered buildings where the distance from a hose connection to the most remote part of the floor exceeds the limits in NFPA 14 based on the sprinkler system type and building type. The minimum residual pressure required for a Class I system is 100 psi (6.9 bar) from the hydraulically most  remote 2 ½ in. (65 mm) hose connection with a flow rate of 500 gpm (1893 L/min), through the two most remote 2 ½  in. (65 mm) hose connections. A pressure-regulating device may need to be used in order to limit the pressure at hose connections to less 175 psi (12.1 bar) static (pressure when not flowing).            Class II Class II are installed for use by trained personnel and are often required in large un-sprinklered buildings. They might also be required to protect special hazard areas, such as exhibit halls and stages. In the past, Class II standpipes were typically installed with a hose, nozzle, and hose rack on each hose connection. Prior to the 2007 edition of NFPA 14, Class II systems were defined as being for use “primarily by the building occupants or by the fire department.” Because of concerns regarding the ability of untrained occupants to safely use the hose and the encouragement of occupants to fight the fire rather than evacuate, the Technical Committee chose to define Class II systems as being for use by “trained personnel or by the fire department.” Class II systems need to provide enough hose stations so that all portions of each floor level of the building are within 130 ft (39.7 m) of a 1 ½ in. (40 mm) hose connection provided with 1 1∕ 2 in. (40 mm) hose or within 120 ft (36.6 m) of a hose connection provided with less than 1 1½ ∕ 2 in. (40 mm) hose connection. The minimum residual pressure required for a Class II system is 65 psi (4.5 bar) from a remote 1 -1/2½ in. (40 mm) hose connection with a minimum flow rate of 100 gpm (379 L/min). A pressure-regulating device may need to be used in order to limit the pressure at these hose connections to less than 100 psi (6.9 bar) residual (pressure when flowing) and 175 psi (12.1 bar) static (pressure when not flowing). Class III Class III systems combine the features of Class I and Class II systems. They are provided for both full-scale and first-aid firefighting. These systems are generally intended for use by fire departments and fire brigades. Because of their multiple uses, Class III systems are provided with both Class I and Class II hose connections and must meet the placement, pressure, and flow requirements for both Class I and Class II systems. Pipe sizing The minimum size pipe for Class I and III standpipes is 4 in. (100 mm). If the standpipe is part of a combined sprinkler system in a partially sprinklered building, that is increased to 6 inches (150 mm). If the building is protected with an automatic sprinkler system, then the minimum combined standpipe size can be 4 in. (100 mm) if hydraulically calculated. The branch lines of the standpipe system are to be sized hydraulically but cannot be smaller than 2 -1/2½ in. (65 mm). Calculating Hydraulically calculating a standpipe system is very similar to that of a sprinkler system because we are calculating the pressure lost in the system to get the required flow to the most remote hose connection. In addition to the required flow from the most remote hose connections, based on the classification we are required to also calculate flow from connections on each standpipe. For example, when calculating a Class 1 Standpipe system in a building that is less than 80,000 ft2 (7432m2) we need to calculate the flow rate of 500 gpm (1893 L/min), through the two most remote 2 ½  in. (65 mm) hose connections at 100 psi (6.9 bar) and also calculate an additional 250 gpm (946 lpm) flowing from each standpipe in the building up to a maximum total flowrate of 1000 gpm (3785 L/⁠min) for buildings that sprinklered throughout, and 1250 gpm (4731 L/min) for buildings that are not sprinklered throughout. Take a look at this video taken from our soon to be released Online Certified Water-Based System Professional Learning Path discussing how to hydraulically calculate a standpipe system. Want to Learn More? Keep an eye out for our Certified Water-Based Systems Professional Learning Path. Also, If you found this article helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, and building & life safety.
Lights on a Christmas tree

Christmas Tree Fire Safety Requirements

With the holiday season fast approaching, the presence of combustible decorations, festive lights, and Christmas trees has also arrived.  The presence of additional furnishings and contents, especially dry and unmaintained Christmas trees and other vegetation can contribute significantly to the fuel load of a space and how quickly a fire can develop and spread.   During this time, those responsible for enforcing fire and life safety codes face the challenge of ensuring businesses and residences are following the provisions for furnishings and decorations, as many consumers are unaware of the potential fire safety hazards they could be installing in their facilities and in their homes.  Here we will discuss the requirements for combustible vegetation and both natural and artificial Christmas trees.   Hazards of combustible vegetation and natural cut trees Combustible vegetation can include a variety of items, such as hay bales, limbs, leaves, and Christmas trees. These items, by their nature, are initially fire retardant. The problem arises when they have been cut and packaged, often early in the season, without access to water for extended periods of time. The fire danger of Christmas trees and similar vegetation increases when the tree is not freshly cut and immediately placed in water when purchased. And, the longer they are on display, the increase in potential for the tree to go unwatered and unmaintained.   The best preventive measures for avoiding a dried out tree include using a freshly harvested tree, cutting the butt or bottom end immediately before placing it in water, and checking the water level frequently to ensure that the tree water container is filled. To check the tree itself for dryness, it is best to check a branch near the trunk and allow it to slide between the thumb and forefinger. When needles shed easily, the tree should be removed or replaced, since trees dry from the inside out.  In 2016, students at Worcester Polytechnic Institute constructed a mock living room setup at the fire protection engineering lab at to demonstrate how rapid and intense a dry tree can burn, complete with furniture, rug, curtains, and a decorated Christmas tree. The dry tree was exposed to a flame and within 25 seconds, the branches were fully engulfed and within another 10 seconds, fire had spread to the ceiling and to nearby furnishings. The entire room was thick with fire and smoke, and flashover occurred within 63 seconds. The Fire Research Division at NIST conducted a series of fire experiments to demonstrate how a watered Christmas tree may be less of a fire hazard than a dry one. The Christmas tree that was maintained in a stand that was kept filled with water prior to testing did not ignite when exposed to the same ignition source as the Christmas tree that was not watered.  A slower growing fire can mean more time to react, escape, and notify the fire department and can also reduce the damage done by the fire.  Where are natural Christmas trees permitted? Natural Christmas trees are prohibited or limited in their placement in occupancies that pose special challenges due to the capabilities of occupants, occupant or management control, or the number of occupants. Some exceptions permit live, balled trees, if maintained, and trees in locations where automatic sprinkler systems are installed. Because a living tree needs moisture to stay alive, a balled, living tree should be placed in a container so that the root structure of the tree can be kept moist. (Note: artificial vegetation, including artificial Christmas trees are not limited in their location). Limitations for where natural Christmas trees can be located is as follows:     Limited quantities of other combustible vegetation is permitted in any occupancy if the AHJ determines that adequate safeguards are in place. Adequate safeguards might include sprinkler protection, limited quantities, moisture content, and placement. It is not the intent to consider a Christmas tree “limited quantity of combustible vegetation” where the display of Christmas trees is otherwise prohibited. For example, no natural Christmas tree, cut or balled, is permitted in assembly occupancies. It is not the intent to allow the presence of natural trees if enforced as being a “limited quantity of combustible vegetation”. The requirement for Christmas trees is more restrictive and should prevail.    Other considerations for natural cut trees No means of egress is permitted to be obstructed by any combustible vegetation item or Christmas tree. The preferred location for a Christmas tree from a property owner’s perspective is often in the lobby, the reception area, or a similar area. However, trees located in these areas often encroach on the means of egress and present an increased danger should a fire occur.  When determining where to place combustible vegetation items or Christmas trees, an important consideration is that they might fall over, especially if children or pets come in contact with the tree or vegetation. Placing a portable heater, other heat source, or heating vent near combustible vegetation is prohibited, because the vegetation might tip and also because the heater will likely prematurely dry the vegetation, increasing the risk of a fire.  To maximize the moisture retention of the tree, the bottom end of the trunk should be cut off with a straight cut at least 1⁄2 in. (13 mm) above the end prior to placing the tree in a stand to allow the tree to absorb water. The tree must then be placed in a suitable stand with water and the water level must be maintained above the fresh cut and checked at least once daily. When the tree shows evidence of drying it must be removed from the building immediately.  On the market today are treatments for natural cut Christmas trees that claim to improve the fire performance of the tree. However, the use of untested fire retardant treatments may actually increase the rate at which the tree dries out and can contribute to the rapid growth of a fire.  Where fire retardant treatments are applied to natural cut Christmas trees (the treatments are not required), the fire-retardant treatment (not the tree) is required to comply with both Test Method 1 and Test Method 2 of ASTM E3082, Standard Test Methods for Determining the Effectiveness of Fire Retardant Treatments for Natural Christmas Trees.  This standard provides a two-step testing process for determining the effectiveness of surface applied treatments for natural Christmas trees to improve fire test response. In order for a treatment to be considered compliant with ASTM E3082, the passing criteria of both Methods 1 and 2 as prescribed in the standard are to be met. Artificial vegetation including Christmas trees  There are no limitations on what occupancies permit the use of artificial Christmas trees so it’s important that their potential contribution to fire development and flammability be controlled.  Combustible artificial decorative vegetation and artificial Christmas trees must now meet the appropriate fire test criteria. This includes requirements for compliance with either the flame propagation performance criteria of Test Method 1 or Test Method 2, as appropriate, of NFPA 701 or a maximum heat release rate of 100 kW when tested to NFPA 289, using the 20 kW ignition source. NFPA 701, Standard Methods of Fire Tests for Flame Propagation of Textiles and Films, establishes test methods to assess the propagation of flame of various textiles and films under specified fire test conditions. NFPA 289, Standard Method of Fire Test for Individual Fuel Packages, describes a fire test method for determining the fire test response characteristics of individual fuel packages in a room when exposed to various ignition sources in a controlled environment.  Each individual artificial decorative vegetation item (Christmas tree) must be labeled, in an approved manner, to demonstrate compliance with one of the fire test options noted above. Additional requirements for Christmas trees Another hazard associated with Christmas trees is the decorative lighting. Electrical wiring and listed luminaires and lighting used on combustible artificial or natural Christmas trees must be listed for that particular application. The listing will also dictate whether the lights have been tested for indoor and/or outdoor use. In addition to the listing requirement, lighting should also be checked for wear and tear and damages. Worn or damaged wiring and loose bulbs may present unsafe conditions.  Electrical lights shall be prohibited on metal artificial trees. Candles and open flames cannot be not be used on or near combustible artificial or natural decorative vegetation and Christmas trees.   Looking for more information? Requirements for artificial and natural Christmas trees and other vegetation can be found in both NFPA 1, Fire Code, Chapter 12 as well as NFPA 101, Life Safety Code, Chapter 10.  The 2021 editions of both Codes were updates to include the specific fire test requirements as well as other clarifications for how to safely include Christmas trees in your business or residence.    NFPA also offers many additional resources on holiday safety, including a Christmas Tree Safety Tip Sheet and information on Christmas tree and decoration fires.  All holiday safety information can be found here. 
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