Showing posts with label NFPA 72 2022. Show all posts
Showing posts with label NFPA 72 2022. Show all posts

Saturday, April 1, 2023

4 Things You Need To Know About The 2022 Edition Of NFPA 72

 4 Things You Need To Know About The 2022 Edition Of NFPA 72

It’s been three years since the National Fire Protection Association (NFPA) published the most recent edition of the wide-ranging standard that spans “the application, installation, location, performance, inspection, testing and maintenance of fire alarm systems, fire warning equipment, and emergency warning equipment and their components.”

2022 Update

A 2022 edition was officially published in September 2021, after thousands of hours of collaboration, review, and debate among a technical committee. The 2022 update is a significant one; there are hundreds of changes in the document, ranging from minor edits of terminology to major items like Cybersecurity. Whether you’re an architect, engineer, contractor, or building owner/manager, NFPA 72 matters.

It will have an impact on how you design, test, install and maintain life safety systems in the future. So even if your jurisdiction will not immediately adopt the 2022 edition of NFPA 72, it’s important to know what’s in the pipeline. Understanding the new edition will enable you to plan for the future and gain insight into how technologies like remote access are changing life safety and building systems.

 

Here are four things you need to know about the 2022 edition of NFPA 72:

 

1) Secondary Power Supply Requirements For Batteries Have Changed

Fire alarm control units typically rely on their local power grid as a primary power supply

Batteries play a significant role in ensuring fire alarm system reliability but are one of the most overlooked items. Fire alarm control units typically rely on their local power grid as a primary power supply, and when that grid is operational, all is fine.

However, should that power failure due to weather interference or technical failure and brownout conditions occur, the secondary power supply comes into play?

Capacity 

NFPA 72 states that the secondary power supply (typically batteries) for the protected premises system shall have sufficient capacity to operate the system under quiescent load (system operating in a nonalarm condition) for a minimum of 24 hours.

At the end of the 24-hour, the secondary power supply must be capable of operating all alarm notification appliances used for evacuation or to direct aid to the location of an emergency for five minutes. If the system incorporates in-building fire emergency voice/alarm communications, then the system needs to operate for 15 minutes.

Charging system

Batteries need to be able to take a charge from the charging system within the fire alarm control unit. Batteries have a life expectancy and also need to be load tested at least annually.

But not all batteries are created equal. So much so that NFPA 72 has decided to raise the bar and impose a new requirement for the batteries used in fire alarm control units.

Listing standards

Examples of listing standards are UL 1989, Standby Batteries, and UL 2054, Household and Commercial Batteries.

 

NFPA 72 states that effective January 1, 2024, rechargeable batteries for the secondary power supply used in control units, devices, and accessories shall be listed or component-recognized by a nationally recognized testing laboratory.

The action was taken because of the acknowledged new dangers posed by today’s battery technologies, primarily due to increased energy densities. Examples of listing standards are UL 1989, Standby Batteries, and UL 2054, Household and Commercial Batteries.

 

2) Fire Alarm Control Units Powered By The Internet Of Things Require New Cybersecurity Measures

Should you be concerned about cybersecurity in a fire alarm control unit? It depends on how it was installed and connected. Many fire alarm systems do not require cybersecurity as they typically use their wiring and infrastructure and do not connect to “outside” equipment.

For example, smoke detectors connected to the fire alarm control unit with wires only used for the fire alarm system, meaning there are no attack vectors that could be exploited. However, this is rapidly changing.

Cybersecurity standards

With fire alarm systems able to connect to the internet, allowing a user to see the status of their system on an app and even perform remote service diagnostics, these cloud-based integrations require new cybersecurity measures.

Underwaters Laboratories, UL, has created a suite of cybersecurity standards. For example, The UL 2900 series of documents covering cybersecurity encompass healthcare, industrial and life safety signaling systems. Now manufacturers can produce fire alarm control units listed to these standards and “build-in” cybersecurity measures.

Patches

But cybersecurity protection doesn’t stop once a piece of equipment leaves the factory. Bad actors are constantly on the prowl for vulnerabilities and patches need to be sent periodically to fix any such avenues for attack.

Just like our computers, mobile devices, etc. all routinely receive updates to help to prevent unwanted attacks, fire alarm systems are no different. How these patches will get delivered and tested is different.

Fire alarms

Fire alarms need to function all of the time, they cannot go down unless service personnel or Firewatch people are on site. When patches are implemented, we need to ensure the system still functions properly, has come back online properly, and has not been compromised.

Fire alarms, unlike our computers, cannot be rebooted over and over trying to fix them when a patch does not function properly. Nor do we have the luxury to replace a fire alarm CPU as quickly as a laptop.

Guidelines for cybersecurity

To address all of this, NFPA 72 has created a new chapter for 2022, Chapter 11 entitled “Cybersecurity.” The chapter is a placeholder for the technical committees to work on for the 2025 edition. But it does offer a glimpse into things to come and provides some guidance for today.

Along with the chapter addition, there is a new Annex J entitled “Guidelines for Cybersecurity.” There is a wealth of information on how cybersecurity measures can be improved for fire alarm and signaling solutions within the new annex.

 

3) Remote Access For Fire Alarm Control Units Requires New Capabilities

Now that systems are being connected for users to see the status of their systems and remote diagnostics have become the norm, NFPA and UL have had to make changes to the allowance and proper usage of these features. UL 864 the Standard for Control Units and Accessories for Fire Alarm Systems has recently added testing protocols for remote access for fire alarm systems.

NFPA 72 has also added guidance for how to properly implement remote access. Like cybersecurity, we do not want to allow bad actors to possibly use the fire alarm system to access larger digital infrastructure and do harm.

Benefits

The benefit of having properly listed equipment and processes for remote access is the door is now open even wider for remote testing, programming, and other applications. Some of the additions to NFPA 72 are that remote access shall not affect the operation or response of the fire alarm or signaling systems.

Remote access can now allow for the first time the ability to test and perform maintenance activities, including the resetting, silencing, or operation of emergency control functions.

Remote access

There are additional requirements such as the system needing a means to manually terminate the remote access connection at the remote device and the fire alarm or signaling system control unit at any time.

Further, remote access needs to automatically terminate within a maximum of one hour of inactivity in the remote access mode. Also, the resetting, silencing, or operation of emergency control functions shall be limited to a portion(s) of the system taken out of service and must be enabled by a qualified person onsite by password or limited access.

 

4) Fire Alarm Systems Must Meet New MNS Standards

The 2007 edition of the NFPA 72 added annex materials to guide allowing a fire alarm system to be used

The role of communication in fire systems has been evolving for years, and NFPA 72 has been evolving with it. The 2007 edition of the NFPA 72 added annex materials to guide allowing a fire alarm system to be used or connected to a Mass Notification System (MNS).

In the 2010 edition, this was taken a step further with the creation of Chapter 24, Emergency Communications Systems (ECS).

UL 2572 Standard

At that time there were no listing standards for MNS or ECS, but that was about to change. UL created a new Standard in 2016, UL 2572 Standard for Mass Notification Systems. This new Standard allows for equipment to become certified to be used for MNS or ECS applications.

Since the Standard has been released many manufacturers have been able to obtain this certification for their respective systems. Starting with the 2022 edition of NFPA 72, control units installed as part of an MNS must be listed by applicable standards such as UL 2572, and Mass Notification Systems.

 

Wednesday, March 15, 2023

Safety on Lithium-Ion Batteries

Safety on Lithium-Ion Batteries 

Lithium-ion batteries were developed in the 1970s and first commercialized by Sony in 1991 for the company’s handheld video recorder. Today everything you see is powered by batteries from smartphones, laptops, scooters, e-cigarettes, smoke alarms, toys even the International Space Station, which makes increased battery safety all the more crucial.

In 2008, Tesla unveiled the Roadster making it the first car company to commercialize a battery-powered electric vehicle. By 2025, the global lithium-ion (Li-ion) battery market is expected to reach USD 100.4 billion, over 50% of which will be used for the automotive market.

NFPA 704 rating of a lithium ion batteries marked 010. Other battery chemistries may have 000 or different designations.

NFPA 704 fire diamond for Li-ion batteries

Flammability

Red 0

Material does no burn under normal conditions

Red 1

Material needs considerable preheating before ignition or combustion occurs

Red 2

Material needs moderate heat before ignition or combustion occurs

Red 3

Liquids and solids can be ignited under ambient temperature

Red 4

Vaporizes under atmospheric pressure; burns easily

Health

Blue 0

Poses no health hazard

Blue 1

Exposure causes irritation

Blue 2

Intense and continued use cause injury

Blue 3

Short exposure causes injury

Blue 4

Short exposure causes major injury or death

Reactivity

Yellow 0

Stable

Yellow 1

Becomes unstable at elevated temperature

Yellow 2

Violent changes at high temperature, reacts with water

Yellow 3

Can detonate with trigger

Yellow 4

Can detonate at normal temperature

Lithium-Ion refers to a family of Lithium-based battery technology. This family includes several sub-families or technologies, such as:

·        LCO: Lithium Cobalt Oxide

·        NCA: Nickel Cobalt Aluminium

·        NMC: Nickel Manganese Cobalt

·        LiFePO4 or LFP: Lithium Iron Phosphate

·        LTO: Lithium Titanate Oxide, etc…………..

Often, we can hear that a product is equipped with “Lithium-Ion” batteries, this does not really have any meaning on the technology used. However, out of habit, the technology referred to as Lithium-Ion is usually LCO, NCA or NMC

Each of these technologies has very different characteristics, particularly in terms of safety.

Lithium-ion batteries are popular because of how much power they can put out at a given size and weight. A typical lithium-ion battery stores 150 watt-hours of electricity in 1 kilogram of battery, compared to NiMH Battery pack (100 watt-hours per kg) or Lead Acid Battery (25 watt-hours per kg). It takes 6 kilograms to store the same amount of energy in a lead-acid battery that a 1-kilogram lithium-ion battery can handle.

However, lithium-ion batteries are extremely sensitive to high temperatures and inherently flammable. These battery packs tend to degrade much faster than they normally would, due to heat. If a lithium-ion battery pack fails, it will burst into flames and can cause widespread damage. This calls for immediate measures and guidelines for battery safety. LCO and NCA are the most dangerous chemicals from a thermal runaway point of view with a temperature rise of about 470°C per minute. In addition, it can be seen that LiFePO4 – LFP technology is slightly subject to thermal runaway phenomena, with a temperature rise of barely 1.5°C per minute.

A lithium-ion battery pack consists of lithium-ion cells stacked together in modules, temperature sensors, voltage tap and an on-board computer (Battery Management System) to manage the individual cells. Like any other cell, the lithium-ion cell has a positive electrode (cathode), a negative electrode (anode) and a chemical called an electrolyte in between them. While the anode is generally made from graphite (carbon), different lithium materials are used for the cathode – Lithium Cobalt Oxide (LCO), Lithium Nickel Manganese Cobalt (or NMC), etc.

When a charging current is provided to the cell, lithium ions move from the cathode to the anode through the electrolyte. Electrons also flow but take the longer path outside the circuit. The opposite movement takes place during discharge with the result that the electrons power up the application that the cell has been connected to.

When all the ions have moved back to the cathode, the cell has been completely discharged and will need charging.

Now need to know why lithium-ion batteries catch fire

A. Manufacturing Defects

Flaws in production can cause metallic particles (impurities) to seep into the lithium-ion cell during the manufacturing process. Battery manufacturers need to ensure stringently controlled cleanrooms for manufacturing batteries.

Another defect could be the thinning of separators which could prove detrimental in actual use. Cells should undergo strict quality-control tests and validation before being sold.

B. Design Flaws

Car companies want to design their cars as sleek and slim while giving the maximum range and performance. These requirements push battery pack manufacturers to come up with compact designs by packing high-capacity cells into a smaller body, messing with an otherwise well-built battery.

Compromising on the design can cause damage to the electrodes or the separator. Either of which could result in a short circuit. Further, the absence of a proper cooling system or vent can cause battery temperatures to rise as the flammable electrolyte heats up.

If uncontrolled, it could result in a chain reaction of cell failures, causing the battery to heat up even more and spiral out of control.

C. Abnormal or Improper Usage

External factors like keeping the battery very close to a heat source or near a fire can cause it to explode. Penetrating the battery pack either deliberately or through an accident is bound to cause a short circuit and the battery to catch fire. That’s why unauthorized disassembly of the battery pack in electric vehicles leads to the lapse of warranty.

Users are advised to only get the batteries checked and repaired from the car maker’s authorized service centers. Even high-voltage charging or excessive discharging of the battery could damage it.

D. Charger Issues

Using poorly insulated chargers can damage the battery. If the charger shorts or generates heat near the battery, it can do enough damage to cause failure.

While lithium-ion batteries have built-in protections to stop them from overcharging, using unofficial chargers can damage the battery in the long term.

Do not charge a device under your pillow, on your bed or on a couch.


E. Low-quality components

In addition to manufacturing defects, using low-quality components is one of the highest causes of battery failures. Increasing competition is driving the prices of batteries down, causing battery manufacturers to cut corners where they shouldn’t. By skimping on poor quality electronics like the battery management system, the risk of battery failure increases.

What to do when a battery catches fire?

If you notice the lithium-ion battery overheat, try moving the device away from flammable materials and cutting of the current supply. If you’re in an electric vehicle, you should immediately evacuate and never attempt to extinguish lithium battery fires yourself. Your health and safety are far more important, call the emergency services instead.

In case of fire,  a standard ABC or BC dry chemical fire extinguisher must be used since these are considered Class B fire. A common misconception is that lithium-ion batteries contain any actual lithium metal. They don’t and that’s why you shouldn’t use a Class D Fire Extinguisher. 

There are new and improved methods to douse lithium fires as well. The Aqueous Vermiculite Dispersion (AVD) is a fire extinguishing agent that disperses chemically exfoliated vermiculite in the form of a mist. However, larger lithium-ion fires as that of EVs or ESS may need to burn out. Using water with copper material is effective but is costly.

Like thermal runaway, Lithium-ion cells have a different level of safety depending on the shocks or mechanical treatments they may undergo during their lifetime.

The nail penetration test is the most revealing way to qualify the safety of a cell technology.

The test presented below is performed by perforating a Lithium Ion NMC cell and a Lithium Ion LiFePO4 cell.

We find here the same extremely stable behavior of Lithium Iron Phosphate cells while the NMC cell ignites almost immediately.

Battery Safety experts advise using water even for large lithium-ion fires. Fires like these may burn for days and it’s important to isolate them from flammable materials and prevent them from expanding.

Purchase and use devices that are listed by a qualified testing laboratory. Always follow the manufacturer’s instructions.

Do not put Lithium Iron batteries in the trash. — recycling is always the best option. — take them to a battery recycling location or contact your community for disposal instructions.

Tuesday, March 1, 2022

Fire Codes Apply for Electromagnetic Locks

 Fire Codes Apply for Electromagnetic Locks

An electromagnetic lock (EM Lock) is essentially an electromagnet in a housing mounted on the door frame, and a steel armature mounted on the door wing. When the magnet is energized, it bonds to the armature and locks the door. To allow access or egress, a switch must be provided to de-energize the electromagnet. It can be difficult to determine which set of code requirements to follow. However, code compliance is crucial when this product is used in an access- or egress-control system. Unlike most locks, electromagnetic locks typically require external release devices such as motion sensors or request-to-exit switches to allow building occupants to exit. In addition, secondary means of releasing the mag-lock are often mandated by the codes, and the requirements vary depending on the type of locking system used.

Prior to the 2009 edition of the International Building Code (IBC), the set of code requirements typically used for doors equipped with electromagnetic locks was the section called Access-Controlled Egress Doors. The 2009 edition added a second set of requirements that could be used, called Electromagnetically Locked Egress Doors. Either of these two sets of requirements can now be used, depending on the application.

The basic difference between these two sections is that the original section, Access-Controlled Egress Doors, required a sensor and push button as release devices, while the new section, Electromagnetically Locked Egress Doors, allows a door-mounted release device instead. This could be panic hardware or a latchset with a request-to-exit (RX) switch, or a bar with an electronic touch sensor.

A building could have several AHJs (Authorities Having Jurisdiction), and more than one code may be enforced for a particular project. The most commonly used model codes in the U.S. are the International Building Code (IBC), the International Fire Code (IFC), and NFPA 101 – The Life Safety Code, but state and local codes sometimes include modifications that affect the use of electrified hardware. It’s usually best to follow the most stringent set of requirements that have been adopted in the project’s jurisdiction.

Here is a summary of the requirements for both sections from the 2009 IBC:

1008.1.4.4 Access-Controlled Egress Doors

·        Applies to entrance doors in a means of egress and entrance doors to tenant spaces.

·        Allowed in Use Groups - A (Assembly), B (Business), E (Educational), I-2 (Institutional - Hospitals & Nursing Homes), M (Mercantile), R-1 (Residential - Hotels, Motels, & Boarding Houses), and R-2 (Residential - Apartments & Dormitories).

·        A sensor must be mounted on the egress side to detect an occupant approaching the doors. Doors must unlock upon a signal from the sensor or loss of power to the sensor.

·        Loss of power to the lock must unlock the doors.

·        A manual unlocking device (push button) shall result in direct interruption of power to the lock – independent of the access control system electronics. When the push button is actuated, the doors must remain unlocked for 30 seconds minimum. The push button must include signage stating “Push to Exit” and must be located 40” to 48” vertically above the floor and within 5’ of the doors. Ready access must be provided to the push button.

·        If the building has a fire alarm/sprinkler system/fire detection system, activation of the system must automatically unlock the doors. Doors must remain unlocked until the system has been reset.

·        Entrance doors in buildings with an occupancy in Group A, B, E or M shall not be secured from the egress side during periods that the building is open to the general public.

1008.1.9.8 Electromagnetically Locked Egress Doors

·         Applies to doors in a means of egress and doors to tenant spaces. The 2009 IBC includes a limitation to doors “not otherwise required to have panic hardware,” which was removed in the 2012 edition.

·        Allowed in Use Groups - A (Assembly), B (Business), E (Educational), M (Mercantile), R-1 (Residential - Hotels, Motels, & Boarding Houses), and R-2 (Residential - Apartments & Dormitories).

·          The door must be equipped with listed hardware mounted on the door leaf, which incorporates a built-in switch to directly release the electromagnetic lock and unlock the door immediately.

·         The release device must have an obvious method of operation, and must be readily operated with one hand under all lighting conditions.

·            Loss of power to the listed hardware must automatically unlock the door.

·          When the new section was added to the 2009 IBC, the technical committee made a change to the proposed language which caused some confusion. A limitation to doors that are “not otherwise required to have panic hardware” was included in the 2009 edition, but it appears that this was not the intent. The limitation was removed and the intent clarified in the 2012 edition of the IBC, and as long as the switch in the panic bar releases the mag-lock, a door required to have panic hardware can be equipped with a mag-lock.

·        With the addition of Section 1008.1.9.8 – Electromagnetically Locked Egress Doors, the door-mounted release device can be used instead of the sensor and emergency push button. Note that this section does not require the mag-lock to release upon activation of the fire alarm or sprinkler system when a door-mounted release device is used. But there are a few issues that are still unclear, even with the 2012 changes.

·           The door must unlock upon loss of power to the “listed hardware,” which in this case is the door-mounted release device. Loss of power to some types of request-to-exit switches will not unlock the mag-lock. We may see a future change to the language so that loss of power to the electromagnetic lock is required to unlock the door, but the code currently addresses the release device.

·        I-2 occupancies (Institutional – Hospitals & Nursing Homes) are not included as acceptable locations for electromagnetically locked egress doors. This use group was added to the Access-Controlled Egress Doors section in the 2009 edition of the IBC, so hopefully the new section will catch up and include the I-2 use group in the future.

·        UL 305, the UL Standard for Panic Hardware, doesn’t address the use of panic hardware to release an electromagnetic lock. There is also a section of the IBC which states that certain doors shall not be equipped with a latch or lock unless it’s panic hardware. This should be changed to reflect the use of a mag-lock released by panic hardware.

The following summaries address each type of system where a mag-lock might be used, and the related model code requirements:

Sensor Release: A sensor automatically unlocks the electromagnetic lock to allow egress.

This is the most common type of system where electromagnetic locks are used. In past editions of the model codes, the applicable section referred to “access-controlled egress doors” which often gave the impression that the requirements applied to all doors with an access control system. A typical access control system which controls access but utilizes a lever handle or panic hardware to allow free egress is not required to comply with this section. The intent is for this section to apply only to electrified locks that are released by a sensor, and the title of this section has been changed in the model codes to clarify the intent.

For these systems, a sensor on the egress side of the door opening must detect an approaching occupant and unlock the door. The door must also unlock upon loss of power to the sensor or locking system, upon activation of the building fire alarm or automatic sprinkler system (until manually reset), and upon actuation of an auxiliary switch – typically a push button. This switch must be located 40-48 inches above the floor and within 5 feet of the door, must be readily accessible, and must be marked “PUSH TO EXIT.” Pushing the button must directly interrupt power to the lock, independent of the other electronics, and the door must remain unlocked for at least 30 seconds.

Recent editions of the IBC/IFC and NFPA 101 include virtually identical egress requirements for these systems, and all of these model codes currently require the UL 294 listing for these applications. It’s important to note that when this type of system is installed on a door that is required by code to have panic hardware, the panic hardware is required in addition to the electromagnetic lock.

Door-Hardware Release: A switch in the door-mounted hardware releases the electromagnetic lock to allow egress.

This type of system typically utilizes a request-to-exit (RX or REX) switch in the lever handle, panic hardware, or sensor bar mounted on the door. Again, the requirements of the IBC/IFC and NFPA 101 are very similar. The model codes require the hardware mounted on the door to have an obvious method of operation, and to be readily operable with one hand and under all lighting conditions. Operation of this door-mounted hardware must directly interrupt power to the electromagnetic lock, and the door must unlock immediately. The door must also unlock upon loss of power to the locking system, and the UL 294 listing is required by the current model codes. Note that this section does not require an auxiliary push button beside the door, or for the door to unlock upon activation of the fire protection system, although some local codes or AHJs may mandate these additional safety overrides.

Delayed Egress: Doors are locked to delay egress for 15 seconds under normal operation but allow immediate egress during an emergency.

There are two types of egress:

·        Free means that someone can exit an egress door without any delay by using only a single motion, such as turning a lever or pushing on a panic bar.

·        Delayed means that there’s a timed delay before someone can pass through the egress door and exit. Typically, this delay is 15 seconds.

Delayed egress is used to:

·        Discourage casual use of certain doors, so pedestrians can’t leave a premises or steal merchandise.

·        Deter elopement of patients, children or inmates from a protected area of a facility.

·        Make possible access control in both directions through selected openings.

Often, delayed egress systems include panic hardware with delayed egress circuitry, but electromagnetic locks are also available with this function. The lock includes an integral timer which allows the door to be opened 15 seconds after an attempt to exit is made – or 30 seconds when approved by the AHJ. The activation switch may be part of the mag-lock, or the timer may be initiated by an external RX switch.

To ensure free egress in an emergency, delayed egress locks must unlock immediately (no 15-second delay) upon activation of the fire protection system or sprinkler system, and upon loss of power. The capability of allowing immediate egress by a switch at the fire command center or other location may also be required.

Under normal operation, the delayed egress lock prevents egress until a force of 15 pounds, maximum, is applied for not more than 3 seconds; an audible alarm will sound in the vicinity of the door, and in 15 seconds the door will unlock to allow egress. After the device has been released by an attempt to exit, it must be rearmed manually - current codes do not allow delayed egress locks to rearm automatically.

Doors with delayed egress locks must also include signage stating, “PUSH UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 SECONDS.” When a delayed egress lock is installed on an inswinging door, or when an AHJ approves a 30-second time delay, the signage must reflect the applicable operation. Specific requirements for the signage can be found in the model codes, and current codes also require the UL 294 listing for delayed egress locking systems.

The model codes include some additional limitations based on the use group or occupancy classification. For example, past editions of the IBC/IFC prohibited the use of delayed egress locks in assembly, educational, and high hazard occupancies, but the 2018 editions include exceptions for doors serving classrooms with an occupant load of less than 50 people, and for secondary exits from courtrooms. Delayed egress locks are allowed in those locations when the jurisdiction has adopted the 2018 edition of the model code, or when approve by the AHJ.

Controlled Egress: In health care facilities where patients require containment for their safety or security, doors may be locked in the direction of egress under normal operation but must allow emergency egress.

The IBC and IFC allow this application to be used in some health care units in hospitals, nursing homes, and other Group I-1 and I-2 facilities. These units might include memory care, maternity, pediatrics, or other areas approved by the AHJ. NFPA 101 includes these requirements in the chapters that cover new and existing health care facilities, and the code allows the doors to be locked where patients’ special needs require specialized protective measures for their safety or security.

According to the IBC and IFC, the building must have an automatic sprinkler system or automatic fire detection system, and activation of these systems must unlock the doors to allow egress. Loss of power must also automatically unlock the controlled egress doors, as well as a switch that directly breaks power to the lock - located at the fire command center, nurses station, or other approved location. A building occupant must not be required to pass through more than one door equipped with a controlled egress lock before entering an exit. The automatic-release requirements listed here do not apply to areas used for psychiatric treatment, or hospital units where listed infant abduction systems are installed.

All clinical staff members must have the ability – including keys or credentials – to unlock the doors for emergency egress, and these procedures must be included in the facility’s emergency plan. Training and drills are crucial in order for staff to be familiar with the egress protocols. Systems used for controlled egress must be listed to UL 294, and emergency lighting must be present at doors equipped with these locks. The requirements of NFPA 101 would not change the type of locks used in these systems (fail safe electrified locks), but the Life Safety Code does include slight variations to the required safety systems and procedures.

Stairwell Reentry: Stairway access doors may be locked on the stair side but must unlock to allow building occupants to leave the stairwell if it becomes compromised during a fire.

The IBC and IFC require all stairwell doors that are lockable on the stair side to have electrified locks that can be remotely released by a switch at the fire command center, or other approved location. (Note: Stair discharge doors may be locked to prevent access to the stairwell but must allow free egress.) For high-rise buildings, the IBC and IFC require the stairwell to be equipped with a two-way communication system if doors are electrically locked. Consult the IBC/IFC for exceptions related to buildings with a single exit stair.

The NFPA 101 requirements for stairwell reentry differ from the IBC and IFC, so it’s very important to refer to the adopted code to verify what is required. For example, NFPA 101 allows doors to be mechanically locked on the stair side when serving four stories or less – the IBC and IFC require these doors to be electrically locked, or never locked. NFPA 101 also exempts some occupancies from the reentry requirements, and includes a section detailing the criteria for “selected reentry” – which allows some doors to be mechanically locked and others to allow reentry.

If mag-locks are used on fire-rated stair doors, the door must be equipped with additional latching hardware to maintain the fire rating. In addition, the mag-locks must meet the applicable requirements on the egress side – sensor release, door hardware release, delayed egress, or controlled egress. Fail-safe electrified locks or fail-safe trim for fire exit hardware is commonly used; fail safe electric strikes are not listed for use on fire door assemblies.

Elevator Lobby Egress: Doors secure the elevator lobby and prevent access to the tenant space but must allow emergency egress from the lobby.

Currently, the IBC and IFC require each elevator lobby to have code-compliant egress via at least one exit. This could include direct access from the lobby to an exit stairwell, or free egress from the lobby to a corridor that leads through a tenant space to an exit. This means of egress must not be restricted, except with a delayed egress lock (most occupancy types) or an exit alarm.

NFPA 101 does allow egress through elevator lobby doors to be restricted during normal operation, if the doors allow emergency egress. The application must be allowed by the applicable occupancy chapter. For example, Chapter 11 (Special Structures and High-Rise Buildings) allows elevator lobby exit access doors to be locked “in other than newly constructed high-rise buildings.” Therefore, this application would not be allowed by NFPA 101 in new high-rise buildings.

The building must have a fire alarm and sprinkler system, and the lobby must have a smoke detection system. Activation of any of these systems (except by manual pull stations), or loss of power must automatically unlock the doors to allow egress. The doors must remain unlocked until the system is manually reset.

The elevator lobby must have a two-way communication system connected to a central control point that is constantly staffed by people who can provide emergency assistance. The electrified hardware must be listed to UL 294, and any latch-releasing hardware on the door must comply with the egress requirements of NFPA 101.

Because the IBC and IFC do not include a section similar to NFPA 101 regarding elevator lobby doors, some cities and states have modified the IBC/IFC to allow these doors to be electrically locked. These modifications typically require fail safe locks which unlock automatically upon activation of the fire protection system, as well as communication between the elevator lobby and a security desk or other location.

Security Interlock: Two or more doors are interlocked so that when one door is opened, the other door cannot be opened; commonly used on clean rooms and high-security applications.

Mag-locks are often used in security interlocks, but this application is not currently addressed in the model codes except when related to a prison sallyport. This type of system could impede egress, so each application must be approved by the AHJ, and additional safety features may be required. For example, to avoid entrapment in the room or vestibule, the AHJ may require emergency override switches in both locations, as well as an override switch on the exterior that is controlled by a key or credential. These switches will allow the doors to be unlocked for access or egress if one door is in the open position, preventing the use of the other door. In most security interlocks, the locks are automatically unlocked upon activation of the fire protection system, to allow free egress. Consult the AHJ to determine what is required.

In most cases, only one of these sections will apply to a particular door opening equipped with a mag-lock. The exception would be a stairwell door that must meet the stairwell reentry requirements on the stair side but would have one of the other applications on the egress side. Remember, refer to the applicable model codes and any state or city modifications to determine whether additional limitations apply, and consult the AHJ if more information is needed.

Code Comparisons - Occupancy Classifications

I-Codes. Until the 2018 edition of the IBC, delayed-egress locks were allowed in all use groups except A – assembly, E – educational and H – high hazard. Beginning with the 2018 edition, delayed-egress locks are allowed on the secondary exits that serve courtrooms (typically assembly occupancies) if the building has a sprinkler system. The 2018 edition also allows delayed-egress locks on classroom doors in educational occupancies if the calculated occupant load served by the door is fewer than 50 people. This gives schools an option if they’re looking for a way to prevent elopement of young children or students who have special needs.

NFPA. The NFPA codes are less restrictive and allow delayed-egress locks in areas of low and ordinary hazard contents, although the Life Safety Code includes restrictions depending on the occupancy. For example, delayed-egress locks aren’t permitted on the main entrance or exit doors that serve assembly occupancies, and they also are prohibited on airport jetway doors. Lodging or rooming houses can have only one door that has a delayed-egress lock per escape path, and residential board and care facilities are permitted to have delayed-egress locks only on exterior doors. The other occupancy classifications aren’t subject to similar limitations.

Code Comparisons - Required Fire Protection System

I-Codes & NFPA. Both sets of model codes require buildings that have delayed-egress locks to be equipped throughout with an automatic sprinkler system or approved automatic smoke- or heat-detection system. This requirement allows either type of system, although the change to the 2018 IBC that applies to courtrooms specifically requires a sprinkler system.

Code Comparisons - Activation Time

I-Codes & NFPA. Both sets of model codes require the delayed-egress timer to begin when a force of 15 pounds is applied for no more than 3 seconds. Prior to the 2015 edition of the IBC, the timer was required to begin after someone attempted to exit for 1 second. The activation time required to initiate the 15-second (or 30 second) timer is permitted to be less than 3 seconds, but it can’t be more than 3 seconds.

Code Comparisons - Automatic Release Delay

I-Codes & NFPA. When the timer is activated, the model codes require the delayed-egress lock to release in the direction of egress after 15 seconds; the AHJ might approve a time delay of 30 seconds. After that period, the door will be unlocked in the direction of egress, and another attempt to exit will allow the door to be opened.

Code Comparisons - Rearming After Activation

I-Codes & NFPA. When the timer of a delayed-egress lock is activated and the lock allows egress after 15 (or 30) seconds, the model codes require the lock to be rearmed manually.

Code Comparisons - Audible Alarm

I-Codes & NFPA. Both sets of model codes require an audible alarm to sound when a delayed-egress lock is activated, but the codes don’t mandate a specific type of alarm. Some products incorporate a continuous alarm, while others have an intermittent sound or even a verbal countdown.

Code Comparisons - Signage Requirements

I-Codes. Signage must state "PUSH [PULL] UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS.” These signs are required for doors equipped with delayed-egress locks (see exception for Group I) and must be mounted above and within 12 inches of the door exit hardware. Beginning with the 2015 edition, signage is required to comply with the visual character requirements of ICC A117.1 – Accessible and Usable Buildings and Facilities. In Group I – institutional occupancies, the AHJ may allow signage to be omitted for certain types of treatment areas.

NFPA. The required text for the signage is the same as that required by the I-Codes: “PUSH [PULL] UNTIL ALARM SOUNDS. DOOR CAN BE OPENED IN 15 [30] SECONDS.” The NFPA codes require signage for delayed-egress locks to be readily visible, with letters not less than 1 inch high, a stroke width of one-eighths of an inch and a contrasting background, durable and located on the egress side of the door adjacent to the release device.

Code Comparisons - Action Upon Alarm Activation

I-Codes. When the fire alarm or sprinkler system is activated, delayed-egress locks must allow immediate egress automatically. This ensures that building occupants can exit quickly during a fire.

NFPA. The NFPA codes are more specific regarding the types of system activation that must unlock the delayed-egress locks for emergency egress. These doors must unlock with no delay in the direction of egress upon the activation of a sprinkler system, not more than one heat detector or not more than two smoke detectors.

Code Comparisons - Remote Release

I-Codes. To allow immediate egress when necessary, the I-Codes require delayed-egress locks to be capable of being deactivated by a switch at the fire command center or other approved locations.

NFPA. Remote release isn’t mandated by the section of the Life Safety Code that addresses delayed-egress locks.

Code Comparisons - Action Upon Power Failure

I-Codes & NFPA. When power fails, both sets of codes require delayed-egress locks to unlock immediately in the direction of egress. A common question about delayed-egress locking systems is whether battery backup is allowed in the power supply of the electrified hardware. The model codes don’t address this specifically, so it often is left up to the AHJ to decide whether delayed-egress locks must release upon loss of the main power to the building or continue to delay egress on standby power. However, based on the requirements of NFPA 72 – National Fire Alarm & Signaling Code, I don’t recommend using independent battery backup in the power supply of the delayed-egress lock. If the fire-alarm system and delayed-egress locks are powered by two different standby power systems, the hardware might not interface properly with the fire alarm after the loss of main building power. Using the same standby power source for the fire-alarm system and delayed-egress locks is preferred.

Code Comparisons - Emergency Lighting

I-Codes & NFPA. Emergency lighting is required by both sets of model codes, on the egress side of the door on which a delayed-egress lock has been installed. It’s important to check for the presence of emergency lighting before you install delayed-egress hardware.

Code Comparisons - Quantity of Locks per Egress Path

I-Codes. For most use groups, only one delayed-egress lock is allowed per egress path. This has changed from past editions of the I-Codes, where a building occupant could encounter only one delayed-egress lock before going through an exit. In Group I – institutional occupancies, such as hospitals, nursing homes and day care facilities, the I-Codes allow two doors that have delayed-egress locks per egress path, with a maximum combined delay of 30 seconds. In Group I-1, Condition 1 and Group I-4, the exception permitting two doors that have delayed-egress locks mandates that the building is equipped with a sprinkler system throughout.

NFPA. For most occupancy classifications, the NFPA codes don’t restrict the number of delayed-egress locks per egress path. Only in lodging or rooming houses does the Life Safety Code limit delayed-egress locks to one device per escape path.

Required Listings

I-Codes & NFPA. Both sets of model codes require delayed-egress locking systems to be listed to UL 294 – Standard for Access Control System Units. If a delayed-egress lock will be installed on a fire-door assembly, it also must be listed to UL 10C – Positive Pressure Fire Tests of Door Assemblies or NFPA 252 – Standard Methods of Fire Tests of Door Assemblies. In addition to the other listings, panic hardware that has delayed egress as a feature must be listed to UL 305 – Standard for Panic Hardware (I-Codes & NFPA) and in some cases BHMA A156.3 – Exit Devices (NFPA only).

If you are a system integrator or access automation installer or even a distributor, it is important to know how to select the best code application for access system on behalf of the customer. Majority of the datasheets and catalogues are not really useful unless you already know what you are getting into. If need any further information contact us on ssaintegrate@gmail.com.

Further Reading

For more on codes and delayed-egress locks:

IBC sections for Delayed Egress:

·        2021 – 1010.2.13

·        2018 – 1010.1.9.8

·        2015 – 1010.1.9.7

·        2012 – 1008.1.9.7

·        2009 – 1008.1.9.7

NFPA 101 sections for Delayed Egress Electrical Locking systems: 7.2.1.6.1