Lithium-ion batteries (LIB) have become the dominant technology in phones, laptops, scooters, electric bikes, electric vehicles, as well as large-scale battery energy storage facilities. As such, it is important to systematically consider their impact on fire safety inside buildings, especially since electrification is a critical part of the effort to limit climate change.
The root of the fire safety challenge is thermal runaway in LIBs. This is a process in which overheating, improper charging, construction defects, mechanical abuses, deterioration due to age and use, and similar causes can start an unstable process resulting in the sudden release of hazardous combustible and explosive gases and the initiation of fire.
Different LIB systems can range from highly reliable to less reliable depending on how they are designed, constructed, and used, as well as their safety features. However, the exponential growth in the number of batteries and the high variability in their types and conditions of use means there will be more fires that are related to this technology. Therefore, we need to understand the challenge at different scales and how it should lead to changes in design and construction.
Fire safety concerns with small-, medium-, and large-scale lithium-ion battery applications in buildings
In terms of small-scale applications of this technology, electric mobility devices such as scooters and bikes are widely used, especially in dense urban areas, as a convenient, inexpensive, and rapid means of transportation. Oftentimes, they are stored close to or just behind apartment doors and may be used with non-standard chargers. These devices can initiate fires that are fast and furious with no warning. Because these fires often have a jet flame component and sometimes throw off flammable pieces, they can spread quickly. When stored next to doors, these devices can prevent building occupants from escaping and complicate fire service response and rescue.
By contrast, typical building fires start locally and are slow moving, giving occupants time to respond or escape. This risk is not theoretical. New York City is already experiencing a dramatic rise in the number of fires caused by electric mobility devices. Frequently, improper charging or placement of these devices has contributed to the risk. At this scale, improvements to manufacturer standards, public education, and building rules on where and how electric mobility devices may be stored or charged can help improve fire safety.
At the medium-scale level, individual electric vehicles and small battery energy storage systems (BESS) for single-family residences can have considerable fire potential and require special attention to mitigate the risk. In addition to manufacturer standards, strategies involving appropriate use of fire protection systems, as well as creating distance between the LIB system and the occupied spaces of a building (e.g., separation of parking spaces, installation of BESS outside occupied spaces), can help reduce the threat of fire.
In large-scale applications, large BESS or parking garages with multiple electric vehicles inside a building can pose a significant fire safety challenge. The nature of hazards associated with these systems is different from that of typical fires. These differences can greatly change the risk profile for buildings, their occupants, and first responders. The challenge is driven by the combined fire, explosion, and hazardous material risk of these events. The total heat release of a gas-fueled car and an electric car might not be very different. However, the fire from an electric car can start fast and furious, with jet flames that make it easier to set the next car ablaze as well.
It takes much more water and time to extinguish a fire from an electric car. In addition, any part of the combustible gasses released from the electric vehicle that does not burn could contribute to an unexpected explosion. A parking area, with multiple electric cars in proximity to one another, may experience a fire that spreads much faster, is more difficult to extinguish (due to safety and extinguishment challenges for the fire service) and is, therefore, likely to burn longer. A large-scale LIB BESS inside a building could pose similar challenges.
For this large-scale challenge, there is a need for greater awareness, as well as increased collaboration between stakeholders (including regulating bodies, first responders, technical associations, owners and developers, and design professionals) to fully define the extent of the challenge and develop an outline of solutions. This is a fast-growing and quickly changing environment, and we need proactive, positive engagement from all involved.
Risk mitigation measures for electric vehicles, battery energy storage systems in buildings
Fortunately, for both electric vehicles in indoor parking spaces and large-scale BESS locations inside buildings, some guidance for risk mitigation is clear. It is helpful that the location of risk for both scenarios is known, allowing for targeted design and mitigation approaches to these spaces. Structurally, the building may be designed to withstand longer fires, and structural hardening can be considered if there is an explosion potential.
For fire suppression, various water-based and non-water-based systems are available, each with pros and cons for their use in a given context.
The firefighting infrastructure in a building can also be improved to ensure adequate water through standpipes, as well as safe access for fire service given the unique risks of the LIB-driven fires.
Finally, there are various options to improve the safety of building occupants through design, whether through increasing redundancy of means of egress in high-risk locations, hardening or changing the location of the means of egress as needed, or designing for a safe shelter-in-place strategy inside the building.
We need positive engagement and collaboration between everyone involved, including the authorities having jurisdiction and regulating bodies to recognize the challenge and allow for successful development and application of creative solutions that are appropriate to the context of each building. This is essential to allow for sustained, safe, and expanded adoption of technologies that are important to our fight against climate change.
About the Authors
Ali Ashrafi, PhD., PE, is a Principal, and Elisa Paone, PE, CFEI, is a Vice President with Thornton Tomasetti.
Codes and Standards | Dec 29, 2022
New York City multifamily owners concerned over fires caused by e-bikes
In 2022, there have been nearly 200 fires and six deaths in New York City caused by lithium-ion batteries used in mobility devices such as electric bikes and scooters.
Sponsored | Resiliency | Dec 14, 2022
Flood protection: What building owners need to know to protect their properties
This course from Walter P Moore examines numerous flood protection approaches and building owner needs before delving into the flood protection process. Determining the flood resilience of a property can provide a good understanding of risk associated costs.
Resiliency | Nov 8, 2022
Oregon wildfire risk law prompts extensive backlash from property owners
A bipartisan bill aimed at protecting property owners from wildfires that was passed by the Oregon legislature has prompted a strong backlash.
Fire and Life Safety | Oct 4, 2022
Fire safety considerations for cantilevered buildings
Bold cantilevered designs are prevalent today, as developers and architects strive to maximize space, views, and natural light in buildings. Cantilevered structures, however, present a host of challenges for building teams, according to José R. Rivera, PE, Associate Principal and Director of Plumbing and Fire Protection with Lilker Associates Consulting Engineers.
Resiliency | Sep 30, 2022
Designing buildings for wildfire defensibility
Wold Architects and Engineers' Senior Planner Ryan Downs, AIA, talks about how to make structures and communities more fire-resistant.
Sponsored | Resiliency | Jan 24, 2022
Norshield Products Fortify Critical NYC Infrastructure
New York City has two very large buildings dedicated to answering the 911 calls of its five boroughs. With more than 11 million emergency calls annually, it makes perfect sense. The second of these buildings, the Public Safety Answering Center II (PSAC II) is located on a nine-acre parcel of land in the Bronx. It’s an imposing 450,000 square-foot structure—a 240-foot-wide by 240-foot-tall cube. The gleaming aluminum cube risesthe equivalent of 24 stories from behind a grassy berm, projecting the unlikely impression that it might actually be floating. Like most visually striking structures, the building has drawn as much scorn as it has admiration.
Fire-Rated Products | Oct 21, 2021
Safti First Fights Through Assertions Made By Plaintiffs Ely Holdings Limited And Greenlite Glass Systems That Safti First’s Fire Rated Floor System Infringed On Their Patent
In a summary judgement dated February 3, 2021, Chief Magistrate Joseph C. Spero of the United States District Court for the Northern District of California ruled that the patent infringement claims filed by Ely Holdings Limited (Ely) and Greenlite Glass Systems (Greenlite) against SAFTI FIRST, a USA fire rated glass and framing manufacturer, could not proceed to trial, finding that the SAFTI FIRST’s fire resistant floor does not violate Ely’s patent.
Sponsored | BD+C University Course | Oct 15, 2021
7 game-changing trends in structural engineering
Here are seven key areas where innovation in structural engineering is driving evolution.
Resiliency | Aug 19, 2021
White paper outlines cost-effective flood protection approaches for building owners
A new white paper from Walter P Moore offers an in-depth review of the flood protection process and proven approaches.
Multifamily Housing | Feb 10, 2021
The Weekly show, Feb 11, 2021: Advances in fire protection engineering, and installing EV ports in multifamily housing
This week on The Weekly show, BD+C editors speak with AEC industry leaders from Bozzuto Management Company and Goldman Copeland about advice on installing EV ports in multifamily housing, and advances in fire protection engineering.