Welcome to this edition of the IAAI’s CFITrainer.Net podcast. Today, we focus on the fire research work of Underwriters’ Laboratories, better known as UL. UL’s research agenda over the past four years has been taking an in-depth look at the many facets of changing home construction and how they impact fire dynamics. In a few minutes, Steve Kerber, the Director of UL’s Fire Safety Research Institute, will be with us here to talk about UL’s most recent and upcoming fire research. But first, a little background.

Even though there have been technological improvements in firefighting equipment and protective gear, firefighter fatalities on the fire ground have actually been increasing. One possible reason for this counterintuitive rise may be the change in buildings construction, construction materials, and home furnishings. Although the intent of this change - or these changes was to improve efficiency, reduce cost, speed construction time, add modern conveniences, and improve sustainability, they may also have an unintended negative impact on safety, fire ignition, and fire spread. Since 2008, UL has invested in research to understand the correlation between changes in construction and the new array of risks for firefighters and consumers. UL research has focused on materials, construction methods and newer home systems (such as photovoltaic panels) that’ll help them understand how they impact the behavior of fire and the composition of smoke, and therefore, how to understand, prevent and mitigate the risks involved. Many of these topics directly affect fire investigation, including potential ignition sources, fire patterns, fire development and spread, and safety concerns.

To discuss recent research findings from UL and to look ahead, we are pleased to have Steve Kerber from UL with us today. Steve is an expert on improving firefighter safety, fire service ventilation, lightweight construction and smoke management fire modeling. He is 13-year veteran of the fire service, a registered professional engineer, and holds advanced degrees in fire protection engineering. Steve, welcome to the podcast.

STEVE KERBER: Thanks Rod.

ROD: So, what are some of the overall findings that are emerging from the body of fire research UL has been doing? What does this mean for fire investigators?

STEVE KERBER: At UL we’ve been lucky enough to receive some funding recently from the U.S. Department of Homeland Security through the assistance of the firefighter grant program, and through that we’ve been able to do all kinds of large scale experiments looking at a lot of the problems the fire service faces and through that we’re starting to put together a lot of trends. Many of them have to do with the fire dynamics in single family homes and how we’ve been able to compare them to what we would consider legacy or my grandfather’s fire that he may have responded to and we’re seeing that fires are spreading faster than they ever have. They’ve got higher heat release rates. We’re seeing that occupants have less time to escape, collapse times are shorter, a whole bunch of pieces.

There’s more hazards today such as solar panel systems and the like and we’ve been picking those components together, essentially the system of the residential home and picking them apart one at a time and looking at how it would impact the fire department response, and clearly, once you understand how it impacts the fire service response, there’s a lot of factors there that would impact fire investigators such as the importance of understanding how the fire got the oxygen, understanding flow paths, understanding the speed at which fire grows and spreads and subsequently what would be seen after the fact by the investigators is going to be different today than it was in the past.

ROD: What has UL research found with regard to PV panels?

STEVE KERBER: I mean, one, they’re a great new advancement in energy, and in order to understand their benefits you also have to understand how they’re going to impact the fire service and maybe ultimately fire investigators. We saw how fire grows and spreads when a fire gets into the panel system. We looked at several safety issues such as how to secure the power, and whether it’s the fire service or fire investigators, it’s important that if you’re going to do your investigation or you’re going to complete your overhaul that you understand how to do that safely, and having DC voltage is something that’s a little bit different for the fire service. I think we’re used to securing the utilities when it involves AC power or natural gas and now we’ve got a DC power source that you can’t exactly turn off, and it was important to understand how the systems work and understand that when you, when you do disconnect the inverter from the panels themselves that you’re just securing the AC side of the power going into the house and not the DC being generated.

We looked at ways to cover the panels and there are proper ways and improper ways depending on what you have to cover the panels using black visqueen, for example, was very successful, versus some of the new modern salvage covers that the fire service would have or fire investigators would have, while it looked like it may have worked, it didn’t necessarily cut down the power enough to make is safe to operate around that system. Understanding that the wiring going from the panels to the inverter could still be energized, so it’s important to cover those panels or to make sure as you’re conducting your investigation, even if it’s in the interior of the house, you need to understand where that wiring runs because if there’s any bit of sun outside, those wires are going to be hot. So, many other topics like that we compiled into an online training program that you can go to UL’s website to view.

ROD: Excellent. You mentioned earlier about lithium ion batteries. What’s UL research found there and why is that important to fire investigators?

STEVE KERBER: In many cases, if you’re going to store the power from the solar panel system, you’re going to need a battery bank in order to do so, and UL has a lot of research going on right now in the topic of lithium ion batteries, whether it’s individual cells or all the way up through computer batteries or larger than that, the storage of batteries and a lot of it’s still underway so there’s not a lot of results to talk about, but I think importantly, that copious amounts of water to control that and understanding the potential fault paths and how those batteries fail could be very important for fire investigators to find exports in order to nail down whether or not that was the source or not.

ROD: When you say copious amounts of water, I just sort of want to clarify because, well, as a guy who doesn’t know enough about this topic, when I think about spraying water around things that generate electricity, could you be more specific?

STEVE KERBER: Sure, absolutely. That the - I mean, the power off of battery storage is going to be different than power out of an AC system or DC system, so it’s maybe not as important for investigators but for the fire service to control those fires. There was some research done, I believe it was by the NFPA, that looked at the ability to use water to suppress the lithium ion battery fires and it was very successful.

ROD: So the part about making this safe, making these batteries and making the photo voltaic panel connections and everything around them safe, that’s handled in your online learning at UL?

STEVE KERBER: Absolutely. We’ve got a very comprehensive online training program that covers the solar panels. There’s also some, we have a new science campaign which we’re calling it that has an entire essentially journal dedicated to the topic of lithium ion batteries, so you’ll be able to see the latest and greatest there.

ROD: Excellent. I’ve seen a lot of that related to vehicles, and that’s an ever-changing pieces as well. So one of the major factors considered in fire investigation is the effect of ventilation on the fire’s growth and development, and the ventilation generated patterns can obviously impact how a fire investigator determines origin and cause. Can you tell us about the research UL has done on horizontal and vertical ventilation and what that means for fire investigators? Can you give us sort of a summary?

STEVE KERBER: Sure. We did several multi-year studies looking at both horizontal and vertical ventilation, and really it’s being able to understand the flow path of how the fire is getting the air, where it’s exhausting its gases, understanding the pressures that exist within the structure to determine where that fire’s going to grow and spread, and specifically for investigators, in order to properly do an investigation of that fire, you need to be paying attention to where that fire got its air from because your heaviest damage may be very remote from where the fire started based on where it got the oxygen from in the very simple fire triangle principles and, again, we have online training programs for both of these explaining how fire grows and spreads, how it reacts to fire service horizontal ventilation, whether it’s doors or windows or how that may be different if a hole is cut in the roof and really walks through the dynamics and the timing of how long it may take some of these things to occur and, of course, understanding that and showing that it happens faster today than it happened in the past. So there might be some - some updates there on current understanding of the speed at which these events occur and really understanding that the stages of fire development aren’t cut and dry. They aren’t very simple from the standpoint of the fire grows, becomes fully developed and then decays.

It’s important to understand that the fire is going to grow, run out of oxygen and it’s going to behave very differently depending on where it gets that oxygen and how much oxygen it gets to determine, there may be several growth stages of the fire depending on how the fire department or how the fire creates its own openings to dictate what the fire service is going to see when they arrive, how they interact with it and then ultimately what’s left for the fire investigator to piece together. So the fire service can have a huge impact on what those patterns are going to look like afterwards depending on how they fight the fire and it’s - I would say it’s - not that this doesn’t happen all the time, but it’s imperative for the fire investigators to really put a good timeline together to understand what happened on the fire ground.

ROD: A lot of changes both in fuels and the way fires are fought are going to really influence these fire investigators in the way they work.

STEVE KERBER: Absolutely, and certainly to add on to that would be today’s construction practices that you’re going to see possibly different mechanisms of fire spread into void spaces, into wall cavities, into attics and things like that based on new uses of materials that you’re going to see out there. Clearly, we’re optimizing how we build houses today taking a lot of the redundancies out of the houses that would have existed in the past by using lighter weight materials and different types of materials, which are going to be, fire investigators really need to stay on top of what these houses are being built out of.

ROD: So I was lucky enough to get out to Governors Island and saw what you were doing with the folks from NIST and from the Fire Department of New York, and I’m going a little bit off script here, but just wondering what blew you away? There was so much information. I saw a lot of firefighters’ faces and a lot of leadership sort of getting pretty visible aha moments.

STEVE KERBER: I don’t think anything really blew me away because, I mean, the Governors Island was a great opportunity to put together and to expand upon things that we had done in the past, so it was really an exercise of taking everything that we learned in the previous ten years to that and doing it in front of the New York City Fire Department leadership and really showing that, hey, just because this happened in a lab in a full scale house that we built in the lab is no different than the structure out in the middle of an island, kind of comparing the real structure verse laboratory test and bringing it all together.

The one thing that it really solidified for us is the whole concept of knowledge verse belief, that we were surrounded by a lot of very experienced fire chiefs that had really strong opinions on what they thought they were going to see, and when they were standing over our shoulders watching the interior video cameras, in many cases they were expecting things to happen that didn’t happen, and I think that’s what you’re referring to is there was kind of some aha’s or some puzzled looks. They believed something was going to happen and when it didn’t, they felt confused, which gave us the opportunity to really explain the fire dynamics to them, take the knowledge that they’ve gained over time through their experience and really try and understand the variables around it because it’s so important not to discount people’s experience. If they’ve seen something with their own eyes, where we’ve had a lot of success, both UL and NIST, has been to validate their experience or allow them to better understand what was going on around their experience because the fire...extremely complex and there’s a lot of things happening at the same time, there’s different points of view. I mean, people can only see one vantage point.

You’re also not going to a ton of fires that are exactly the same so it’s hard to put the pieces together, so many times we start applying things that we saw in one setting to another setting where maybe they don’t apply. So it was a really great opportunity to, I mean, basement fires was a great example, putting water in through a window in a basement fire to gain the upper hand. We had measurements and thermal imaging views of the top of the stairwell and a lot of those chiefs swore that the moment water went in through that basement window that a large amount of fire was going to come up through those interior stairs and actually the opposite happened.

Things cooled off quite a bit and they had experienced in their career being in that position and getting extremely hot when water got put into a window and we had to help put that into perspective, again, by explaining being in the flow path verse not being in the flow path, pressure differences, gas cooling, understanding steam expansion verse gas contraction for cooling and putting a lot of those pieces together, and I think we’ve really come a long way in the last five or six years because of these projects and because of the tremendous partnership between the researchers and the fire service. The fire service really wants to get better as does the fire investigation community, and if we can get them visuals to better understand what they’re seeing in the field, then everyone’s going to advance forward.

ROD: It was beautiful opportunity to tie science and observation to the folks that are out there, in an emotional way, I’m sure very often responding with concern for life, having that concern for life sort of taking out of the equation and being able to allow them to observe the fire, I think that was so incredibly valuable and it was great to watch. I think it’s going to be, as you said, a wonderful move forward. So when you think about this, it leads to safety and it leads to making the fire ground a place where firefighters can be more effective and be more careful with their own lives and hopefully save more lives. Can you talk a little bit about the safety perspective for firefighters and for fire investigators?

STEVE KERBER: Sure. I think that it all comes around to understanding the hazards, and clearly, the fire service is showing up for life safety and that is absolutely paramount, however, it doesn’t need to come to the detriment of their own safety, and clearly, it’s a hazardous job, but if we can allow them to better understand a lot of the hazards that they’re up against and specifically how they’ve changed over time; there’s many firefighters that have received training and there’s no continuing education requirements, so what they know about fire behavior might have been 30 years ago and haven’t looked at any changes since, and, I mean, we’ve had projects that have looked at the collapse hazards, we’ve looked at smoke toxicity, so what’s in the smoke during overhaul, we did a really comprehensive study on that and, I mean, that is paramount for fire investigators as well, and I know others have studied this, but we saw that I think it was 97% of the smoke particulate in the air during the overhaul stage is so small, it’s invisible to the naked eye. So when we don’t have some hard measure to say this environment is safe to conduct your investigation in, we might be unknowingly exposing our folks to conditions that we shouldn’t be exposing them to, and I think we need to take that a lot more seriously because there isn’t a gas measurement that you can make that says it’s okay to operate in that environment, so there’s probably some more work that needs to be done there.

We’ve got a project right now that would be very interesting to investigators, and that’s fires that start on the outside of structures and also attic fires where we’re seeing that as energy codes evolve and demands are being put in place get higher energy efficiency on the wrapping of homes that a simple change of switching out a solid piece of wood for a rigid foam board, for example, is going to do great energy-wise, but we’re seeing fire spread that is on the order of going, starting at the base of the wall and winding up in the attic in less than two minutes, and when you look at the average response time of the fire service, you’re going to have very different damage and very different hazards upon arrival today then may have been experienced in the past, and clearly, as the fires get into the attic, they become every difficult to fight. There’s a large fuel load up there and a collapse hazard as well as a fire dynamics hazard of if you get underneath it and make some openings, it might seek a low pressure through the crew that’s trying to find the attic fire, so we’re also studying that as well. So there’s a lot of new hazards that need to be well understood because you want to understand them ahead of time, not when you’re showing up to deal with it and get surprised, so we’re trying to get ahead of the game a little bit with our, with the firefighter research, which haven’t really happened in the past that much.

ROD: I know the work you’re doing is very, very appreciated around the country when I’ve traveled. I hear about you and Dan Madrzykowski and UL and NIST and the things that you’re doing, it’s blinding how excited people are. They’re just sort of blown away. So what am I missing, anything that you want to communicate to fire investigators that we haven’t talked about?

STEVE KERBER: I think the big thing is where to go for more information. I think that certainly we scratched the surface and we just created the UL Firefighter’s Safety Research Institute within UL which was just tremendous. It’s given us more resources, it’s given us a focus to completely serve the fire service community around the world and with that we’ve launched a new website, ULfirefightersafety.com. We also have a Facebook page, a Twitter account, a YouTube channel and the purpose behind that is to, in the past it’s been we get a grant, we conduct the grant, two years later we release a report and an online training program. A lot happens in that two years and we want to bring the fire service, the fire investigation community into the projects so not only do we have a fire service technical panel that’s serving us, we want to put every update on our web page as it happens, also invite people to participate, invite people to come watch tests so folks know what’s going on all along the way and not just at the end because there’s a lot of interesting information that comes out, a lot of potentially lifesaving information that gets developed along the way, so we want to open up the process and make it a huge partnership so if folks could go there and watch what’s going on. They’ll be pretty much up to the week with what’s happening.

ROD: Thank you very much for your time, Steve. We’re really grateful.

STEVE KERBER: I appreciate the opportunity, Rod.

ROD: We have links to a lot of this material available on this podcast page, so please be sure to check those out. Staying up to date on fire research is critical to fulfilling the requirements of NFPA 1033 and this is one way to do that.

That concludes this podcast. Remember to take a minute to click some of the resource links on this podcast page to learn more about the results of UL’s recent fire research. Stay safe, we’ll see you next time on CFITrainer.Net. For the IAAI and CFITrainer.Net, I’m Rod Ammon.

ULfirefightersafety.com

Overview of New Science: Fire Safety

UL Fire Research

UL Fire Safety Thought Leadership

Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction (Impact of Horizontal Ventilation)

Effectiveness of fire service ventilation and suppression tactics (Impact of Vertical Ventilation)

Firefighter Safety and Photovoltaic Systems

Structural Stability of Engineered Lumber in Fire Conditions

Upholstered Furniture Flammability