AUTHOR: Brian O'Connor

Sprinkler Protection for Flammable and Combustible Liquids

We live in a world where flammable and combustible liquids are all around us. Gasoline, rubbing alcohol, nail polish remover, hand sanitizer, and cooking oils are just a few common examples. When storing large quantities of flammable liquids, it's important to understand how to protect them properly because of their rapid rate of fire growth. This blog will dive into some of the requirements for the sprinkler protection of stored flammable and combustible liquids. Designers will often go to NFPA 13 Standard for the Installation of Sprinkler Systems for all sprinkler system requirements, but many don't know that flammable and combustible liquid storage is covered by NFPA 30 Flammable and Combustible Liquids Code. What is a flammable or combustible liquid? Before discussing sprinkler protection requirements for these liquids, the first step is figuring out what exactly we're talking about when we say flammable or combustible liquids. When defining these liquids, we often refer to their flash point, which is the temperature at which a liquid gives off enough vapor to form an ignitable mixture with the air. With that in mind we define flammable and combustible liquids as follows: Flammable liquid – flash point below 100°F (37.8°C) Combustible liquid – flash point at or above 100°F (37.8°C) NFPA 30 then further divides flammable and combustible liquids into classifications.  These will be used to determine the correct design criteria to your storage. Classifications of flammable and combustible liquids are as follows: Flammable Class IA = Flash Point <73°F (22.8°C) & Boiling Point < 100°F (37.8°C) Flammable Class IB = Flash Point < 73°F (22.8°C) & Boiling Point > 100°F (37.8°C) Flammable Class IC = Flash Point between 73°F (22.8°C) and 100°F (37.8°C) Combustible Class II = Flash Point between 100°F (37.8°C) and 140°F (60°C) Combustible Class IIIA = Flash Point between 140°F (60° C) and 200°F (93°C) Combustible Class IIIB = Flash Point above 200°F (93°C) Gathering information When determining when and how to protect the storage of flammable and combustible liquids it is important to gather information to make the correct design decisions. First it is important to know which standards to follow. For the storage of flammable and combustible liquids we should start in NFPA 30. There are certain requirements in NFPA 30 that will instruct users to follow the requirements for various commodities in NFPA 13 when necessary. To determine design criteria, you will first need to know the quantity of flammable or combustible liquids being stored. As well as how the liquid is being stored (whether it is rack storage, shelf storage palletized, or stacked.) Next, you need to be aware of what containers the liquid is stored in. The type of containers for flammable and combustible liquids can be stored in varies greatly; some examples of acceptable container material include metal, plastic, or glass. The material the container is made of will also dictate the volume of the container that the liquid can be stored in. A complete list of acceptable containers is located in section 9.4.1 in NFPA 30. How to protect it Fire protection system design criteria for protecting the storage of containers of flammable and combustible liquids are provided in Chapter 16 of NFPA 30. The design criteria are contained in 12 tables that address different storage situations and configurations and include both sprinkler and foam-water sprinkler systems. Three decision trees assist the user in identifying the appropriate table to be used. In these tables you will find maximum storage height, maximum ceiling height, required aisle width, required sprinkler arrangement as well as if in-rack sprinklers are required. It is important to understand that sprinkler systems are designed to protect against certain hazards and increasing those hazards can cause your fire protection system to be overwhelmed. This issue can be addressed by developing a change management plan that triggers safety and compliance reviews when certain changes occur. Although NFPA 13 usually contains all of the requirements for the installation of sprinkler systems for the storage of flammable and combustible liquids NFPA 13 and NFPA 30 work in harmony to help ensure sprinkler systems are designed in a way that can help save people and property. Check out the November/December 2020 issue of the NFPA Journal where the ‘In Compliance' column talks specifically about how to properly store and protect alcohol base hand rub. Have you recently worked on a project that included flammable or combustible liquids? Let us know in the comments below what you think the biggest or most common challenge is. 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

Guide to Fire Extinguisher Inspection, Testing and Maintenance

Portable fire extinguishers are often times our first line of defense against small fires and chances are you aren't too far from one right now. Like any lifesaving equipment you want to ensure that it is operable at all times so it will work when you need it most. With proper inspection, testing and maintenance (ITM) protocols fire extinguishers can be long lasting, reliable options for combating a small fire early on. This blog will address the NFPA 10, Standard on the Installation or Portable Fire Extinguishers requirements that help ensure your extinguisher is ready. The requirements are broken down into three different sections on inspection, maintenance and testing. In each section there is information on what needs to be done (Procedures), who is allowed to perform the work (Qualifications), how often each step needs to be done (Frequency) and how to document the work (Recordkeeping). Inspection Procedures Performing an inspection is the easiest thing you can do to ensure your extinguisher can be used reliably and effectively in an emergency. At a minimum, inspection needs to consist of the following steps: Make sure it is located in its designated place Make sure the extinguisher is visible or that there is signage indicating where the extinguisher is located Make sure you can easily access the extinguisher Ensure the pressure gauge is in the operable range or position Make sure it is full, this can be done by just lifting the extinguisher or you can weigh it For wheeled extinguishers, make sure the condition of tires, wheels, carriage, hose, and nozzle are acceptable For nonrechargeable extinguishers, operate the push-to-test pressure indicators Qualifications You are not required to be certified in order to perform an inspection; any knowledgeable, competent person should be able to do it. Frequency NFPA 10 requires extinguishers be inspected when they are initially installed and once a month after that. You should inspect extinguishers more frequently if they are installed in locations where they are more prone to rust, impact or tampering. Recordkeeping Records of the monthly inspections need to be maintained by either putting a tag or label on the extinguisher or by having it recorded on paper or electronic files. The following items need to be recorded: The month and year of the inspection The person conducting the inspection These records need to be maintained for at least 12 months. Maintenance Procedures Maintenance procedures must include the procedures detailed in the manufacturer's service manual and a thorough examination of the basic elements of the fire extinguisher, including the following: Mechanical parts of all fire extinguishers Extinguishing agent Expelling means Physical condition This is completed by doing an external examination. An internal examination can also be required as part of your maintenance. Details on how to do an internal examination are located in your fire extinguisher service manual. Qualifications Maintenance needs to be performed by a certified person. Certification requires that a person take a test acceptable to the AHJ . A certified person needs to, at the very least, be familiar with the requirements in NFPA 10. Frequency Fire extinguishers need to have an external maintenance examination conducted on a yearly basis, at the time of hydrostatic test, or when specifically indicated by an inspection discrepancy. Extinguishers need to have an internal examination conducted at anywhere from 1-6 year intervals depending on the type of extinguisher. For example, a dry chemical, stored pressure fire extinguisher must have an internal examination every 6 years, see NFPA 10 Table for more details on other types of fire extinguishers. Recordkeeping Each fire extinguisher shall have a tag or label securely attached that indicates that maintenance was performed. The tag or label needs to identify the following: Month and year maintenance was performed Person performing the work Name of the agency performing the work Extinguishers also need a verification-of-service collar located around the neck of the container if an internal examination was conducted. That collar needs to have: Month and year the work was performed Name of the agency performing the work Hydrostatic Testing Procedures  A hydrostatic test always begins with an internal and external examination of the extinguisher as described in the maintenance section. The extinguisher then has many of its components removed so it is stripped down to pretty much just the shell and hose and is filled with water at a certain pressure for a certain time. The extinguisher must then be completely dried to get rid of all of the water and is then reassembled and recharged. If there is any leakage, distortion or permanent moving of couplings the cylinder fails the hydrostatic test and it must be condemned. Qualifications People who do hydrostatic testing need to know what they are doing because it can be dangerous if performed incorrectly. They need to be trained, certified, and have the correct equipment and facility to perform the testing. Frequency Like internal maintenance, hydrostatic testing is done at different intervals based on the type of extinguisher you have. These are done either every 5 or 12 years. See Table 8.3.1 in NFPA 10 to see which applies to your type of  extinguisher. Recordkeeping For low pressure cylinders a label is required to be attached to the extinguisher. It needs to contain: The name of the person conducting the test The date of the test The pressure at which the test was performed For high pressure cylinders the testers identification number and the date must be stamped onto the shoulder, top, head, neck or foot ring. This was intended to be a helpful guide to extinguisher ITM but it doesn't contain all the details that the requirements in NFPA 10 contain. Since there are many different types of extinguishers, there are slightly different requirements based on the extinguisher's characteristics. Electronic monitoring, which is a viable option as a replacement for your monthly inspections was also not addressed here.  If you're interested in more information about portable fire extinguishers check out these resources: Location and Placement of Fire Extinguishers - Fact Sheet Where are Fire Extinguishers Required - Blog Use the comments below to share your experience with fire extinguishers. What challenges have you faces when conducting inspections? What have you found to be the most common violation? 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.

Airport Terminal Windows, More Than Just A Pretty View

During this era of Covid spending time at airports seems like a distant memory. Looking out those large  windows onto the apron, which is where aircraft are parked, you can see several fire protection measures at work. The surface of the apron is sloped away from the building in case of a fuel spill, the building itself is constructed of a certain level of fire resistance and the aircraft loading walkway has a pressurization system for safe egress, but what about that window you are looking through? NFPA 415, Standard on Airport Terminal Buildings, Fueling Ramp Drainage, and Loading Walkways, contains requirements for the protection of occupants and property for airport terminals, including their large landscape windows.  Glass vs Glazing? If you are looking in the standard one of the first things you might notice is that it doesn't use the term ‘window' or ‘glass'. Rather, the terms ‘opening', and ‘glazing material' are used. Glazing is used because most windows are not made from solely glass, they are usually made from a mixture of layers or laminated glass, fiberglass, acrylics, or other plastics and the term glazing material covers all of these. The term opening is used for much the same reason, it is more generic and can apply in more situations if the opening is technically not a window. For example, if the term window was used this wouldn't cover the use of a door, which would present many of the same hazards being addressed in NFPA 415. When do airport terminal openings need to be protected? If there is an opening in a wall that is within 7 ft of the floor and potential fuel spill points are less than 100 ft horizontally then the window needs to be protected with an automatic water spray system in accordance with NFPA 15, Standard for Water Spray Fixed Systems for Fire Protection. There has been testing that has shown the radiant heat from a fuel spill fire can be expected to break glass windows 75 ft away and can potentially ignite combustible materials within the building. If the window is between the finished floor and 7 ft there is a greater potential for occupants to be injured and so that is the threshold for the application of this requirement. How do I provide protection? While NFPA 415 says to follow NFPA 15, additional guidance that is proposed for the 2022 edition of the standard explains the intent by adding that the user should follow the vessel exposure protection provisions of NFPA 15. This makes sense since we are providing the window with exposure protection from the fuel spill fire. Something to keep in mind when designing a system like this is that you can take water rundown into consideration, which allows you to increase the vertical spacing of your nozzles up to 12 ft. Another common question we get about design is whether protection is needed to be provided for the entire window or just the bottom 7 ft. A proposed change to the 2022 edition clarifies that it is the intent for the system to protect the entire opening. For more information on the design of glazing assemblies, please see Annex C of NFPA 415 which goes further into detail about glazing materials and the dangers aviation facilities can pose. Check out this ‘In Compliance' article which gives an overview of all fire protection features in an airport. Let us know if you have any experience with the fire protection of airport terminals or send us a picture of the next water spray system you find. If you found this blog helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, building and life safety.
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What is the Secret about Private Operating Mode?

Everyone is familiar with the sound of a fire alarm and flash of the visual notification thanks to drills that are required at schools and the workplace. They are typically designed in a way so that everyone can see and hear, no matter where you are located in the building. What happens when you are in a building such as a hospital or correctional facility where notification of everyone in the facility could cause panic, interrupt delicate surgeries or damage a newborns hearing or vision? Are buildings permitted to have an alarm that privately notifies only those who need to take action? If so, what alternate requirements must be followed? This blog takes a look at private operating mode alarm systems, and their requirements. What is it?   Private Operating Mode is an audible or visual signaling only to those persons directly concerned with the implementation and direction of emergency action initiation and procedure in the area protected by the fire alarm system. Provided that those persons receive alarm notification, audible and visible signaling is not required to other building occupants who are not responsible for the implementation and direction of emergency action. For instance, if this was implemented in a correctional facility, the officers would need to be notified since they would be the ones who implement emergency actions, which would be to evacuate the inmates.   Private operating mode differs from public operating mode in several ways. In general, private audible notification is permitted to have a lower volume than public mode. Both public and private audible notification allow the AHJ to reduce or eliminate the audible if visual signals are provided. Visual notification is required in all public spaces per the ADA when using public mode and NFPA 72 National Fire Alarm and Signaling Code gives you specific requirements for how bright they must be, for private visual notification it is just required to be of sufficient quantity and intensity to meet the intent of the system. When can I use it?   The main rule when looking at where you can use private operating mode comes from NFPA 101 Life Safety Code. It says that private operating mode is allowed in places where occupants are incapable of evacuating themselves because of age, physical or mental disabilities, or physical restraint. Certain places come to mind such as detention/correctional facilities, prisons, jails, hospitals, same day surgery centers and day care occupancies. Ultimately, this should be a discussion you have with your AHJ to determine if the facility in question meets the requirements to allow it to be protected with a private operating mode fire alarm system.   Healthcare Specific Requirements   NFPA 99 Health Care Facilities Code contains some specific requirements regarding the use of the private operating mode for healthcare facilities. It clearly allows the use of private operating mode but adds additional requirements. For example, the notification needs to identify the smoke zone or floor area, floor and building where the responsible staff need to respond. It also needs to be heard throughout the facility except where notification would adversely affect patient care (surgical rooms, patient sleeping rooms, psychiatric care areas, etc.) Notification can also be omitted in areas that would interfere with patient treatment or areas where occupants will be alerted by staff. This is often done by coded messages like “Dr. Blaze, Code Red fourth floor west wing,” so that everyone can hear the message but only those trained to recognize the message will respond. This is still a subject that needs to be better understood by fire alarm designers and AHJs alike. It requires an analysis of the situation and an understanding of human behavior. Private operating mode isn't a one-size-fit-all solution. It must be integrated into the facilities emergency response plan and the responsible personnel must be properly trained in order for the system to work correctly, but if done right it has the potential to save lives. Let me know if you have any experience with private operating mode installations or approvals in the comments below. Also look out for changes in the 2021 edition of NFPA 101 which further aligns with the requirements found in NFPA 72 and NFPA 99. 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.
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6 Facts about Sprinkler System Corrosion and Steps to Help Minimize its Effects

Corrosion is a costly problem for sprinkler systems. It can cause leakage which can lead to impaired sprinkler systems, water damage, and eventually replacement of the entire system. This blog looks at  what corrosion is, where we can find it, how it affects a sprinkler system, and how to spot and prevent it. What is corrosion? Generally, when we refer to corrosion we are talking about when a metal reacts with its environment which leads to deterioration of the metal. In sprinkler systems this is often when oxygen reacts with iron to form iron oxides, which we commonly refer to as "rust." This is further accelerated when it occurs in the presence of water, which helps the reaction. While this is the most common, there are other types of corrosion that can affect a sprinkler system such as microbiologically influenced corrosion (MIC) and galvanic corrosion.  For any metallic component of a sprinkler system there is both external and internal corrosion. While both of these issues can lead to system failure, internal corrosion is more difficult to detect and causes more issues. Internal corrosion usually begins to form at the air/water interface while external corrosion is more dependent on the environment. Where does corrosion occur? There are many locations where piping and sprinklers are more susceptible to external corrosion. Most of these locations have different elements in the atmosphere that can speed up corrosion. A few common examples include: Areas with fertilizer or manure (animal pens) Pools or areas containing pool chemicals Areas near the ocean that are exposed to outside salt air Salt storage Pipe is in contact with soil Areas with excessive moisture (steam room) Listed corrosion resistant sprinklers and corrosion resistant piping, fittings and hangars are required to be installed in places where corrosive conditions are known. Meanwhile all pipes and fittings installed on the exterior of the building are required to be corrosion resistant. Internal corrosion on the other hand occurs most commonly where metal, water and air are in contact with one another. This occurs in both wet and dry pipe systems. For wet pipe systems, corrosion occurs most often near the pockets of air that could be trapped in high points. For dry and preaction systems the corrosion occurs most often at the low points because that is where any residual water builds up. How does corrosion affect a sprinkler system? Corrosion has a detrimental effect on sprinkler systems, causing the components to fail. For piping this can take the form of pinhole leaks or having rust buildup limit the flow of water (see image below). For sprinklers, corrosion can clog the water discharge orifice, affect the deflector and discharge pattern, or completely seal the plug, preventing water from reaching the fire. Other components such as piping hangers and fittings can also be susceptible to corrosion, which can lead to further complications.  What can I do to minimize corrosion? Completely eliminating the possibility of corrosion is nearly impossible, however there are some steps that can be taken to help reduce the amount of corrosion in a system: Better pipe material: When trying to delay corrosion a great place to start is looking at the material used. Certain types of piping are more resistant to corrosion, such as plastic CPVC, copper or galvanized steel. There are also benefits to using thicker piping since rust will not eat through the wall of the pipe as quickly. Using higher quality material may cost more up front but it will extend the life of the system and increase reliability.  Corrosion resistant sprinkler: When sprinklers are installed in areas susceptible to external corrosion, they need to be corrosion resistant. This means that they need to be either made out of corrosion resistant material, covered with a special coating such as wax, or plated with a corrosion resistant metal (see image below). Water supply: NFPA 13, Sandard for the Installation of Sprinkler Systems, requires the water supply to be evaluated to determine if it contains any unusual corrosive properties or is likely to contain MIC. If it does, then you need to either install piping that is corrosion/MIC resistant, treat the water with water additives, implement a monitoring plan, or fill your system with nitrogen for dry or preaction systems. Wet Pipe: Air Venting: NFPA 13 requires a vent to be located at a high point in the system to allow air to be removed by either a manual or automatic valve. This can be a reasonable approach on wet pipe sprinkler systems to reduce corrosion activity. The purpose of the air venting valve is to exhaust as much trapped air as possible from a single location every time the system is filled, thus having less oxygen for the metal to react with.  Dry Pipe: Drain Water Out of System: Just like how in wet pipe systems you want to remove the air out of the piping, for dry pipe or preaction systems you want to remove the water. Dry pipe and preaction systems are required to be pitched to a low point drain so that water can be removed from the system. Since most corrosion occurs at the air/water interface this will help prevent corrosion. Dry Pipe: Nitrogen: For dry pipe or preaction systems nitrogen can be used to fill the sprinkler piping network instead of air. When a system is filled with nitrogen it  contains very little oxygen, which is a vital ingredient in the corrosion process. Nitrogen can be provided through cylinders or a nitrogen generator.     How can I spot corrosion? Some corrosion can be easily identified while others can be hidden. During your annual floor level inspection of piping, fittings and sprinklers be sure to keep an eye out for exterior corrosion which can be identified by its orange-brown color and rough texture.   Internal corrosion is more difficult to identify during your annual inspection so an assessment of the internal condition of piping is required to be conducted every five years. Outside of that assessment, the effects of both internal and external corrosion can be seen by looking for water stains or leaking pipe where corrosion could have created pinhole leaks in your system by eating through the wall of your piping (see image below).       What do I do if I see corrosion? When there is significant corrosion buildup that is detrimental to sprinkler system performance, that section of piping, or sprinkler needs to be replaced. If corrosion is bad enough sometimes an entire system needs to be replaced. Addressing these issues will help ensure the reliability of your sprinkler system, increase the life expectancy of your system and in the long run save you time, energy, and money. Share your experience working on a system that was installed in a corrosive atmosphere in the comments below. What was the biggest challenge or lesson learned? 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.

Arizona ESS Explosion Investigation and Line of Duty Injury Reports Now Available

Two reports from the Surprise, Arizona Energy Storage System (ESS) explosion that occurred in April, 2019 were published this week.  One report, titled, “Four Firefighters Injured In Lithium-Ion Battery Energy Storage System Explosion – Arizona” is written by the UL Firefighter Safety Research Institute and is part of a Study of Firefighter Line of Duty Injuries and Near Misses. The other report, “McMicken Battery Energy Storage System Technical Analysis and Recommendations” by DNVGL, on behalf of Arizona Public Service, is an investigation report into the incident. The DNVGL report looks at how we can prevent this incident from happening again and the UL report analyzes first responder considerations with regards to the incident. Both documents are examples of how we can learn from past incidents to improve our codes and standards, increase the safety of our first responders, and build a safer environment. The Incident On April 19th, 2019 an explosion occurred at the McMicken Battery ESS in Surprise, Arizona injuring four firefighters. The battery ESS was placed into service in 2017, which is prior to the publication of NFPA 855. The system was comprised of 10,584 Lithium Nickel Manganese Cobalt (NMC) battery cells organized in modules and racks within an ESS specific walk-in enclosure. The system included a total flooding clean agent fire suppression system, a very early smoke detection apparatus, and an HVAC system. The entire system could supply 2MW over one hour (2MWh) and was used to supplement solar panels at the time of the incident. While there was some information about the incident already known, these reports provide a great level of detail, insight and recommended paths forward. Technical Analysis Report The DNVGL report documents a thorough investigation that was conducted on the incident. It gives a lot of relevant background on the technology, the layout, and associated hazards. After building a foundation of knowledge about how batteries fail, the report analyses the factors that contributed to the failure and how we can prevent this from happening in the future. Some of the major conclusions reached in the report are as follows:   The cause of the incident was most likely an internal failure in a single battery cell which was caused by a defect in the cell. The clean agent fire suppression system that was installed was not designed to prevent or stop thermal runaway. The absence of barriers allowed thermal runaway to propagate from cell to cell. Flammable off-gases concentrated to create a flammable atmosphere and did not have a means to ventilate. The emergency response plan did not address extinguishing, ventilation, or entry procedures. Some of these items are addressed by NFPA 855, Standard for the Installation of Stationary Energy Storage Systems while others are included in the section of the report, “ Shortcomings that should be addressed in NFPA 855.” NFPA codes and standards are living documents that are constantly looking for ways to improve and keep up with new technology. Recommended improvements are always welcome in the form of Public Inputs or Public Comments.  First Responder Report This UL report gives an overview of the fire department and the incident. When addressing the responding fire departments, the document talks about their training, experience, equipment, and personnel. Regarding the Arizona incident, the report covers the building construction, the energy storage system, and responder PPE, and it walks through the timeline as well as provides a detailed incident narrative. This report does a great job addressing some of the contributing factors that led to the incident and firefighter injuries. Some of those factors include: HAZMAT training curricula does not cover basic ESS hazards. There was no way to monitor the conditions of the ESS container from a safe location. The emergency response plan didn't address mitigating ESS hazards and the plan was not provided to the responding personnel before the incident. Deflagration venting and explosion prevention systems were not provided in the ESS unit. The issue of training first responders on the basics of ESS hazards can be addressed through an updated NFPA online training course, Energy Storage and Solar Systems Safety Online Training for Fire Service Personnel. It is encouraging to see that such a collaborative approach was taken in response to this incident to determine what happened and what could be done to prevent this type of equipment failure in the future. In the field of ESS, one of the major needs of the industry is better information like this or other publicly available test data to help guide our codes and standards. A number of related reports, articles, relevant standards, and other content can all be found on NFPA's ESS webpage Let us know what your thoughts are on these reports or if you've had any recent experience with ESS installations by commenting below.

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