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Sarah Kunkel 2006 MAAFS Annual Meeting May 5, 2006

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. UV in Arson Investigation. Ultra violet lights marketed to arson investigators for decades

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Sarah Kunkel 2006 MAAFS Annual Meeting May 5, 2006

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  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 • Amount of Ignitable Liquid • Time Exposure • Visualization of Various Ignitable Liquids • Visualization on Various Materials • 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 carpet 10 μL gasoline on asphalt tile 300 μL gasoline on asphalt tile 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 10 months later 1st Day

  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 Weathered Gasoline 50% 90% 75%

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

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

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

  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, 1997. 405-11. • Forestal, R. Use of Ultraviolet Light in Fire/Arson, Bomb, and Environmental Investigation. Firehouse Magazine September 1994: 48-50 • Brucker, D. Chief Deputy Fire Marshal, Allegheny County Emergency Services. July 18-27, 2005. Pittsburgh, Pennsylvania. • U.S. Fire Administration. Arson in the United States (Topical Fire Research Series). The Administration. January 2001. 1(8): 1-3 • Ultra-Violet Products. Use of Ultraviolet Light in Arson Detection [Application Bulletin-UVP-AB-107]. 1997 • Stauffer, Eric. Technical Working Group for Fire and Explosives Discussion. March 21, 2006.

  26. Questions???

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