Welcome to the IAAI’s November, 2009 CFITrainer.Net podcast. This month’s podcast features chimney fires and includes recent news on surgical flash fires, a proposed national arsonist registry, lightning research and an innovation in personal protective equipment.

With fall soon to turn to winter in the northern hemisphere, many people have begun using their heating systems and fireplaces for warmth. The U.S. Consumer Product Safety Commission reports that there are 25,000 chimney fires every year causing 30 fatalities and $120 million in losses. What should the fire investigator know about chimney fires and how to assess a chimney as a possible fire cause? We turned to Dale Deraps. He’s the President of Advanced Chimney Techniques for a closer look at chimney fires. Dale, thanks for being with us today.

DALE DERAPS: Very good.

INTERVIEWER: What are the potential causes of chimney related fires?

DALE DERAPS: Well we’re going to break it down into two main groups. You’ve got fires that happen internally to the chimney system and that would be combustible creosote buildup. In some localities you might have an oil soot fire. In other areas it might go back to like animal debris, leaves, straw, nesting debris and that type of material that may have been drug into the chimney system by the lack of a screened chimney cap and animal intrusion. That would cover fires internal to the chimney.

The other aspect would be fires that occur outside the chimney. You have a tremendous release of heat when these combustibles burn. If the chimney systems are adequately thick enough and built basically according to code, it hopefully has enough thermal mass there to absorb that heat and not have it char combustibles around it and ignite, but often we have birth defects, which would be improper construction, and there may be thin spots or embedded lumber that can catch fire, and the other could be just deterioration in an old system built substandard to today’s standards and subsequent pyrophoric conditioning of the lumber around the chimney system.

In a chimney fire you can have your initial fire and based on how thick the chimney is it can be two, three, four hours later when the final temperature rise occurs on the exterior surface and pyrophorically conditioned lumber can catch fire. Often the fire departments who will come put out a fire, go back to the station and then it will kindle in the attic, oh, several hours later because your heat will continue to build on the outside of the system, but those are the main issues there.

INTERVIEWER: What should the investigator look for when considering the chimney as a possible fire cause?

DALE DERAPS: The first thing you would look for - often chimney fires will leave evidence in the form of what we’d call a third stage creosote and we actually classify the soot and creosote in the chimneys first stage, second stage, third stage. First stage creosote would be just a fine soot that would basically show normal operation and a complete combustion and very little combustible material left in the chimney. The second stage is a glazed creosote. Basically, that’s non-combusted volatiles, tar fog and such that comes off the wood burning process basically done in an oxygen starved situation and a low temperature fire where you’re sweating off a lot of the combustibles that collect inside the chimney system, and the third stage to look for is the actual combusted creosote. It’s been burnt, it’s released its heat and if you’ve even seen these kid’s Fourth of July snakes, you light them on the sidewalk, this is going to be very similar. It’s a black foamed material that’s very lightweight and often multicolored, but it’s definite evidence of a chimney fire.

Additionally you might look for cracked tile. If it’s a stainless steel liner system or a Class A chimney you would look for buckling in the liner. Perhaps a stainless steel cap or any chimney cap could be discolored, and you might see a definite burn pattern on the underside of the cap, and sometimes the screening will actually melt away. Chimney fires can get hot upwards of 2000 degrees and will actually melt steel, and aluminum chimney caps could evaporate under these kind of temperature conditions.

INTERVIEWER: What special investigative steps should the investigator take in the case of a possible chimney related fire?

DALE DERAPS: The first thing we will do is try to get as many pictures as possible. You’ll never go wrong taking plenty of pictures and having that documentation. Once we’ve made our observations about the external and the internal situation, often with the chimney fire the foamed creosote will like foam inward and can sometime actually block off a chimney. Then we would clean the chimney and get all the debris down to the bottom and get it pulled out to be able to inspect for cracking is going to be your primary issue. But also need to look around the outside of the flue and crawl through the attic and look for charred or embedded lumber. Oftentimes we’ll find lumber that’s been pyrophorically conditioned to the point of, just right to the point of ignition, which makes it particularly dangerous that the second or third occurrence that they might have could much more easily start a fire.

Once they’ve achieved those kind of temperatures, you lower the combustion temperature on any of the combustibles that are built too close. Almost nobody in the past has provided the proper clearances to combustibles around a masonry chimney. Often the lumber is right up against it and you go through one or two of these occurrences, you can dramatically lower the next ignition temperature. So they become increasingly dangerous.

When it comes to metal chimney systems, the Class A and even Class B systems, again, anything charred, but the most common mistake is from the original installers would be lack of attention to providing the proper clearances to combustibles, and the other thing to look for would be missing attic insulation shields are a big one in this area. In original construction they would skip that attic insulation shield and blow sometimes even cellulose insulation up against the chimney, or lack of fire stops where attic insulation can fall from the attic on down to the top on top of a fireplace or into an area. Insulation traps heat, so always be looking for proper fire stops, spacers or attic insulation shields because this could be a big issue.

Another big issue is the type of equipment. Prior to 1986 or 1987, fireplace equipment, wood stoves, wood furnaces, were not required to have any secondary combustion to burn smoke. Anything built passed 1987 or 1988 in terms of an appliance should have a functioning system to burn the smoke, be it a catalytic combustor or some scheme built by the manufacturer into the appliance to burn smoke. Many, many, many of the manufacturers for a period of time used catalytic combustors in their wood stoves, their wood fireplaces or their fireplace inserts. The catalytic combustors only had about a five year lifespan, and they’re expensive to replace and the housings warp. After 15 years many of the homeowners out there will just skip it, I don’t need this catalytic combustor.

Well, you go back to the dirty burning high creosote creating situation that is going to set up the stage for the chimney fire, so one thing to keep in mind when you’re looking at these occurrences, something is out of whack. The fire’s burning, too oxygen starved, too much fuel, not enough air, not enough temperature, they’re holding it down, too big a stove for the area that they are attempting to heat so they keep it strangled down and create a lot of rich smoke. There’s usually a cause that can set the stage, but then if the chimney fires occurred and actually got out of the structure, you’re going to look for more likely a birth defect, a bricklayer who didn’t have saw in his box when he was building it and left an embedded rafter or something on that order.

INTERVIEWER: Thanks for your time and contribution to CFITrainer.Net, Dale, and now, a look at recent news in fire investigation.

Surgical flash fires are in the headlines with the death of an Illinois woman from severe burns sustained on the operating table. 500 to 600 of these fires occur every year and the cause is typically an electrical tool igniting the oxygen rich environment under a surgical drape. Although the incidents of surgical fires decreased in the 1970’s when safer anesthetics replaced older ones like ether, 100 percent oxygen is still used with patients. There is a rise in concern over these fires because of the increased use of the electrosurgical devices and the replacement of cloth hospital drapes with drapes made of disposable synthetic fabric that is more flammable.

In other news, a bill proposing a national arsonist registry passed the U.S. House of Representatives on September 30, 2009 called Managing Arson through Criminal History or MATCH Act, House Resolution 1727 of the 111th Congress establishes guidelines and incentives for states to establish criminal arsonist and criminal bomber registries and to require the Attorney General to establish a national criminal arsonist and criminal bomber registry program and for other purposes. As of the recording of this podcast, the bill has been referred to the Senate Judiciary Committee for consideration. The bill’s progress can be tracked on Govtrack.US using the search term HR1727.

The Lightning Safety Alliance has undertaken a research project to learn more about the ways that lightning enters and damages homes and buildings. LSA is soliciting information on lightning incidents, fires and damage from the public and emergency services professionals. Findings will be presented to the NFPA’s technical committee on lightning protection. For more information, visit lightningsafetyalliance.com.

Researchers at James Cook University in Australia have developed the cool me vest. The vest is similar in design to chemical cold packs found in first aid kits. By cooling the body’s core under heat conditions, the vest is designed to reduce heat stress and shorten the recovery period for fire responders. Although the vest is single use, it is made of recyclable material.

Finally, let’s close with some news from the IAAI. The IAAI Board of Directors just met at their midyear meeting in Metairie, Louisiana and they endorsed the utilization of the ATF’s BATS, the Bomb Arson Tracking System. BATS is a secure web based information sharing system that serves as a direct link for federal, state and local agencies to the data maintained by the U.S. Bomb Center or USBDC. BATS serves as the national sole repository maintained by statute and attorney general directive for information pertaining to bombing, explosives and arson incidents.

Using internet connected computers, fire investigators can easily document any fire or explosion using standardized language and share information with other investigators. Fire investigators are able to capture details of arson and bomb cases including the area of origin or device placement, fire descriptors, casualties, dollar losses, collateral crimes, device components and descriptions of how a device was delivered while maintaining absolute operational security. Investigators can use BATS to perform trend analysis, generate statistical reports and compare incidents for similarities in motives, device components, suspects and crime methodologies for possible investigative leads nationwide.

IAAI has been awarded a grant of $962,820 to continue the growth of the IAAI distance learning network. Phase 6 of this program will make possible additional class offerings on the CFITrainer.Net website, continuation of these monthly podcasts for fire investigators and expand the new training tools such as the skill assessment practicums and the fire investigation technician professional credential. Upon recommendation of their site selection chair, David Sneed, the IAAI Board of Directors selected Dover Downs, Delaware as the site for the 2012 annual training conference. After the 2010 conference in Orlando, Florida and the 2011 conference in Las Vegas, Nevada, the Board of Directors focused on a site in the northeastern United States to facilitate access and attendance from a large fire investigation community in that region. Information on this year’s ATC in Orlando can be found on the IAAI website, Firearson.com.

That concludes this IAAI CFITrainer.Net podcast. We’ll see you again next month