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The Limitations and Advantages of Ultraviolet Light Sources in the Detection of Ignitable Liquids at Fire Scenes Sarah Kunkel 2006 MAAFS Annual Meeting.

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Presentation on theme: "The Limitations and Advantages of Ultraviolet Light Sources in the Detection of Ignitable Liquids at Fire Scenes Sarah Kunkel 2006 MAAFS Annual Meeting."— Presentation transcript:

1 The Limitations and Advantages of Ultraviolet Light Sources in the Detection of Ignitable Liquids at Fire Scenes Sarah Kunkel 2006 MAAFS Annual Meeting May 5, 2006

2 UV in Arson Investigation Ultra violet lights marketed to arson investigators for decades Very few reliable studies to support their claims

3 Ultraviolet Light Test Objectives Determine capabilities of UV light source Determine limitations of UV light source Determine whether UV light source is a practical approach to ignitable liquids detection at fire scenes

4 Ultraviolet Light Source Model UVSL-26P by UVP in California Rechargeable Three modes of operation –Short wave (254nm) –Long Wave (365nm) –Dual

5 Testing Performed I.Amount of Ignitable Liquid II.Time Exposure III.Visualization of Various Ignitable Liquids IV.Visualization on Various Materials V.Visualization on Various Burnt Materials

6 I. Amount of Ignitable Liquid All amounts of gasoline tested on carpet and asphalt tile –10 μL –25 μL –50 μL –100 μL –150 μL –300 μL

7 I. Amount of Ignitable Liquid All amounts detectable on carpet and asphalt tile 50 μL gasoline on asphalt tile 50 μL gasoline on carpet

8 I. Amount of Ignitable Liquid 10 μL gasoline on asphalt tile 300 μL gasoline on asphalt tile 10 μL gasoline on carpet 300 μL gasoline on carpet

9 I. Amount of Ignitable Liquid Close-up: 10 μL gasoline on carpet

10 II. Time Exposure All tested on carpet and asphalt tile –30 minutes –60 minutes –120 minutes –180 minutes –240 minutes –300 minutes

11 II. Time Exposure All amounts detectable on the tile and carpet at 10 months 1st Day 10 months later

12 III. Ignitable Liquids Tested All liquids tested at 10 μL and 50 μL on asphalt tile Ignitable liquids tested: –Gasoline (Unevaporated, 50%, 75%, and 90% evaporated, and Base) –Diesel fuel –Lighter fluid –Linseed oil –Various ignitable liquids used to calibrate the canine detection team

13 III. Ignitable Liquids Tested Only gasoline, diesel fuel, and linseed oil detectable on all material at all amounts Weathered gasoline fluoresces brighter than non-weathered –90%>75%>50%>non-weathered Base gasoline not detectable Gasoline from various companies indistinguishable

14 III. Ignitable Liquids Tested 90%75% 50% Weathered Gasoline

15 IV. Flooring Materials Tested Carpet Linoleum Foam Carpet Padding Fiber Filled Carpet Padding Asphalt Tile Wood Flooring

16 IV. Other Materials Tested 100% White Cotton T-shirt Jeans Human Skin Manila Folder White Printer Paper White Notebook Paper Yellow Notebook Paper Paper Towel

17 IV. Flooring Materials Tested Must use only short wavelength on linoleum Carpet and asphalt tile worked under long, short, and dual wavelength Mostly questionable positives for fiber filled carpet padding and wood flooring

18 IV. Other Materials Tested Negative results on jeans and cotton t-shirt Skin –Remain detectable on skin between 8-9 hours –Canine team did not detect after 3 hours –Fluoresced after 5 hand washings Paper products –Both liquids fluoresced on all paper products –Light absorbed when liquid was still wet

19 V. Burnt Materials Tested Carpet Linoleum Foam Carpet Padding Fiber Filled Carpet Padding Asphalt Tile Wood Flooring

20 V. Burned Materials Tested

21 V. Burnt Materials Tested Only short and dual wavelengths visualized the ignitable liquids Gasoline less visible than diesel fuel on all materials Results varied from unburned materials –Less positive results –Carpet absorbed light

22 Additional Results Dawn detergent masks ignitable liquids from the canine teams but no affect on fluorescence Exposure to water does not affect fluorescence

23 Conclusions UV light only useful in detection of gasoline and diesel fuel Not affected by water, but burning of material does affect visibility Useful with small volumes and at long exposure times Fluorescence caused by dyes in ignitable liquids

24 Acknowledgements Don Brucker, Allegheny County Fire Marshal’s Office Bob Huston, Allegheny County Crime Laboratory Dr. Graham Rankin, Marshall University

25 References DeHaan, J. D. Kirk’s Fire Investigation 4th edition. Prentice Hall, Forestal, R. Use of Ultraviolet Light in Fire/Arson, Bomb, and Environmental Investigation. Firehouse Magazine September 1994: Brucker, D. Chief Deputy Fire Marshal, Allegheny County Emergency Services. July 18-27, Pittsburgh, Pennsylvania. U.S. Fire Administration. Arson in the United States (Topical Fire Research Series). The Administration. January (8): 1-3 Ultra-Violet Products. Use of Ultraviolet Light in Arson Detection [Application Bulletin-UVP-AB-107] Stauffer, Eric. Technical Working Group for Fire and Explosives Discussion. March 21, 2006.

26 Questions???


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