There are a few potential code changes underway regarding fire protection for vehicles in various parking arrangements for the latest edition (2022) of NFPA 13. These code changes stem from a growing concern regarding adequate fire protection in parking garages due to the seemingly unusually large string of recent parking garage fire losses.
Those fires sparked three code change proposals. The first being the removal of automobile parking from the Ordinary Hazard Group 1 occupancy list in NFPA 13 Section A.18.104.22.168. The second is adding sidewall sprinkler protection to car stackers of three or more cars to the Extra Hazard Group 2 occupancy list in NFPA 13 Section A.4.3.6. The third and final suggestion ties into the first and proposes reclassifying the automobile parking occupancy from Ordinary Hazard Group 1 to Extra Hazard Group 2.
The reason for deleting parking garages from the Ordinary Hazard Group 1 stems from the concern that it is an inadequate hazard classification for such fires. Automobile design has continuously been evolving since cars were invented, and now modern vehicles contain significantly more plastic.
Additionally, hybrid/electric drive cars pose a different risk with lithium-ion batteries that have the potential for thermal runaway and can burn for days. Not to mention the configuration and proximity of the cars measuring typically one to two feet apart, which promotes fire spread.
The proximity and configuration also play a role in the reason for including additional sidewall sprinkler protection for car stackers consisting of three or more cars. The concern here comes from the extensive shielding effect that occurs from having a car fire (one that presumably starts in the interior or under the hood of the car) with two additional cars in between the fire and a sprinkler, thus making it nearly impossible to “put the wet stuff on the red stuff.”
Additionally, garage structures tend to be extremely inaccessible by fire apparatus, so getting water on the fires without a means already in the garage (sprinkler or standpipes) is extremely difficult. There have been many parking garage fires over the years and those fires have caused a lot of damage, so at first glance, it looks like a lack of adequate sprinkler protection is the issue. But with many, especially the ones outside the United States, parking garages often are not sprinklered.
The reason for the last proposed code revision is a combination of the first two. Car stackers most closely resemble a lot of the modern parking garages, especially automated ones, and they are classified as Extra Hazard Group 2. So it makes sense to classify parking garages similarly — especially as the cars themselves are now a more significant hazard than initially anticipated.
Some feel that the safer, more conservative route (lacking full-scale fire test data) is to change the occupancy to Extra Hazard Group 2 to ensure adequate protection rather than the complete removal of any design guidance.
As previously stated, modern vehicles present new hazards, due to the incorporation of larger quantities of combustible materials (e.g., fuels, plastics, synthetic materials, etc.) into their designs. As alternative fuel vehicles are popularized, concerns regarding their unique hazards, burn characteristics and typical burn duration have been raised. Compared to older cars, modern cars burn differently.
Modern parking garages have optimized space requirements for vehicle parking and storage, and often implement automated retrieval features and car stacking, which presents unique hazards as well. Thus, it raises the question if the safety infrastructure of these parking structures has kept pace.
As a result, the NFPA Research Foundation has initiated a project titled “Modern Vehicle Hazards in Parking Garages and Vehicle Carriers.” The goal of this project is to quantify the fire hazard of modern vehicles in parking structures and vehicle carriers to guide the relevant technical committees (e.g., NFPA 13, NFPA 88A and NFPA 301). This research project is scheduled to issue a report in late May or early June 2020 and should be welcome guidance for the NFPA technical committees of interest.
Today’s Code Requirements
One can find code requirements for parking garages in two NFPA standards: NFPA 13 Standard for the Installation of Sprinkler Systems and NFPA 88A Standard for Parking Structures. For the purposes of this column, we will focus on NFPA 13 since it is where the proposed revisions are currently being debated.
The only time parking garages are explicitly stated in the 2019 NFPA 13 is in the appendix (A.22.214.171.124), where it is listed as an Ordinary Hazard Group 1 occupancy and two references in Sections 126.96.36.199 and A.188.8.131.52 that render them exempt from any code requirements in those respective sections. NFPA 13 defines Ordinary Hazard Group 1 occupancies as “(1) spaces with moderate quantity and low combustibility of contents and (2) stockpiles of contents with low combustibility that do not exceed 8 feet.”
Parking garages have been classified as an Ordinary Hazard Group 1 occupancy since the 1970s. Even though times have changed and technology has progressed, the reasoning for the parking garage classification has always stayed the same: “the combustibility is low and the quantities of combustibles is moderate and fires with moderate rates of heat release are expected.”
Coincidentally, that quote comes from the 1980 NFPA 13 committee response to a proposal to reduce parking garage occupancies to light hazard occupancies. The proponent of this proposal cited the “relatively low heat output” found in the full-scale fire testing done on parking garages in 1973. The NFPA 13 Technical Committee response to this proposal stated, “the automobiles presently manufactured contain much more plastic than the automobiles manufactured before 1973 and therefore the heat content of each vehicle is much greater.”
If the committee in the ’80s saw enough of a plastic increase from 1973 to essentially call the full-scale testing irrelevant, imagine how much more testing and re-evaluation needs to be done now in 2020 with even more plastic components, hybrid drives and fully electric cars.
Recent Parking Garage Fires
The main reason cited for proposing revisions to the protection of parking garages has been a string of devastating parking garage fires over the last few years. Parking garages experienced 6,000 fires annually in the United States between 2013-2017 but several — both in the United States and abroad — have garnered attention including:
• On Feb. 14, 2017, a fire at a Disneyland parking garage involved nine cars.
• On Sept. 17, 2018, at King’s Plaza in Brooklyn, N.Y., a parking garage fire involved 135 vehicles.
• On Jan. 7, 2020, a fire at a Norwegian Airport destroyed at least 300 cars as well as partially collapsed the five-story parking structure.
But by far the most infamous fire (listed as a part of the statement of the problem for the NFPA 13 proposed revision) was the subject of an NFPA Journal article in March 2019: the Dec. 31, 2017, parking garage fire in Liverpool, England, which destroyed 1,300 vehicles as well as the five-story concrete parking structure.
And while there is no doubt these fires and the many others not mentioned were all devastating and ideally should have been better protected, there’s a bit of a debate about whether the current code requirements are the root cause of this issue. Upon further inspection, one can find that many of these parking garages were not sprinkler-protected (very common in Europe).
But that is not to say the United States is perfect. Twelve cars were lost on Jan. 31, 2019, in one of Newark (N.J.) Airport’s unsprinklered, open parking garages.
But again, the fires cited previously in New York and at Disneyland had code-compliant sprinkler systems but still had multi-car fires. So what gives?
Changes in Automobile Design
As consumers demand larger and heavier vehicles such as trucks and SUVs, manufacturers have met those demands and government requirements for improved fuel efficiency using plastics. Studies show that in 1996, the amount of plastics in U.S. light vehicles was approximately 230 pounds and just over 6 percent of total vehicle weight.
Those numbers have increased to 385 pounds and 10 percent of total vehicle weight. This presents a significant increase in energy content during a fire, both in intensity and duration, compared to older vehicles.
One area where plastics have a significant effect on the fire hazard of modern vehicles is the gas tank. The share of cars built with plastic gas tanks has been estimated to be between 75 percent to 85 percent, potentially resulting in an earlier release of fuel from the tank from a fire in the vehicle or a fire in adjacent vehicles.
The introduction of alternative fuel vehicles — such as hybrid, all-electric, hydrogen fuel cells and LNG — adds a whole set of complexities to the protection equation.
In addition to the dramatic changes in the design and manufacturer of vehicles today, the way cars are stored also has changed, further complicating what constitutes proper fire protection. Some of these changes include:
• Car stackers, where the first vehicle is parked on a platform and then lifted by a machine, allowing another vehicle to be parked underneath. Car stackers can double or even triple the parking capacity without any excavation work. The 2019 edition of NFPA 13 addresses car stackers in Section A.4.3.6 as Extra Hazard Group 2.
• Automated parking systems (APS), where the driver parks the vehicle in a portal, then walks out of the entrance, the doors to the portal close and the automated parking system uses some combination of dollies, shuttles and vertical towers to place the vehicle in a non-normally occupied storage space. The storage space can be above or below grade, and the vehicle can be hundreds of feet away from the portal.
The idea behind APS is to maximize the number of vehicles stored in a particular space so the cars are much closer together than traditional parking garages. This type of facility is not well-addressed by NFPA 13.
• Car sales towers, where cars are placed in a glass tower by a mechanical system with one or more cars per tier, up to 12 levels tall. These towers are not for public access and used for sales advertising and display, not long-term storage. This type of facility is also not well-addressed by NFPA 13.
Status of Changes to NFPA
Per the 2013 NFPA 13 Handbook: “Automobile parking garages, as shown in Exhibit 5.6, and restaurant service areas, as shown in Exhibit 5.7, are examples of ordinary hazard (Group 1) occupancies. Even though there is gasoline in the automobiles, the fire record on these occupancies demonstrates that the fires in parking garages are typically limited to one car and do not pose an excessive challenge for the sprinkler system to control.”
This has been an industry standard of care for ages, but the NFPA 13 Technical Committee knows this needs to change to adapt to modern vehicle design.
The NFPA 13 Technical Committee has been working on the draft of the 2022 edition of the standard and produced the First Draft Report, which was posted on the NFPA website Feb. 25, 2020. The Technical Committee is now in the public input phase in the effort to develop a Second Draft; public comments were received through May 6. The Second Draft Report is scheduled to be posted Jan. 20, 2021.
The NFPA 13 Technical Committee — specifically, the Sprinkler System Discharge Criteria Subcommittee — has been wrestling with changing NFPA 13 concerning parking garage protection. Although the subcommittee is unanimous in removing parking garages from the list of Ordinary Hazard Group 1, they are not unanimous on what hazard classification it should be changed to and what design guidance to provide, if any. The NFPA Research Foundation report on this subject cannot come soon enough.
It’s too early in both the NFPA 13 revision process as well as the NFPA Research Foundation project to have a definitive gauge or idea as to what exactly the future holds for protecting parking garages (both traditional and nontraditional types). However, a glimpse into the past can show us there is no doubt this research and re-evaluation of the occupancy classification is much needed, and the results are greatly anticipated by all.
Luckily, the NFPA codes and standards revision process is very transparent and can be monitored by any interested person via NFPA’s website (www.nfpa.org). In the meantime, we’ll keep an eye out for automobile parking garages in NFPA 13’s 2022 Edition.