COLLECTING IGNITABLE LIQUID SAMPLES

By

Rodger Broome'

Fire Investigator

West Jordan Fire Dept.

Maintaining the integrity of the evidence taken from fire scenes is becoming more important because of its scrutiny in the Courts. Ignitable liquids are present in many fire scenes and some of them are not there by accident. Collecting samples of these ignitable liquid fuels has not been a major hurdle. However, sometimes we stumble upon better ways of doing things by accident. I found some good methods for collecting, transporting and storing ignitable fuels on a case I worked this summer.

I was called out to a rubbish fire inside a building that was under construction. The main fuel package was a pile of scrap lumber. There were the classic signs of an ignitable liquid pour which resulted in approximately $1,500.00 in concrete damage beneath the scrap lumber. I needed to obtain samples from the burned area and a suspicious canister of liquid that was nearby. I went to the station to get some evidence containers to process the scene.

I got to the station and went to the store room where we keep our unused paint cans and paper bags for evidence collection. This room is where we keep these items because it is where we keep the medical supplies for our ambulance service. It is clean and is kept locked. I was trying to figure out how I was going to collect the liquid samples I needed. My eyes fell upon the IV administration equipment and a light seemed to go on for me. I saw a collection of syringes, needles, angio-catheters and blood tubes. It was so simple and obvious. Here was some equipment that was easy to use, engineered for laboratory conditions and was always available to me. I selected some 3cc and 5cc syringes, several 18ga. metal needles, some 18ga and 16ga angio-catheters and some red top blood tubes.

I selected the equipment from what was there with a few guidelines in mind.

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• The 3cc and 5cc syringes were selected to obtain large enough samples for providing a quantity that was testable at the Crime Lab.
• I selected large bore needles and angio-catheters to avoid their clogging during the collection of liquids likely to contain debris.
• I selected the red top blood tubes because they have no additives inside for medical diagnostic testing.
• I selected both angio-catheters and metal needles because the catheters were flexible to gather samples from the ground while the metal needles allowed the insertion of the liquids into the blood tubes after being collected.

I stripped the angio-catheter off of its needle and placed it on the end of a syringe. I put the open end of the angio-catheter into the liquid puddles that were on the floor. Hydrocarbon fuels float on the water so, I was careful to keep it toward the surface. I sucked up the liquid from the puddle into the syringe. I replaced the angio-catheter with an 18ga metal needle. I inserted the needle through the top of a blood tube and the vacuum sucked the liquid into the blood tube. I marked the label on the blood tube with my initials and the number I assigned to it as evidence.

Example: RB001

I discarded the sharps in a sharps container and the syringe was placed in the garbage to prevent it from being reused by accident. The container I needed to get a sample from was a spray canister like the type used for fertilizing and pest control. I wasn't able to get my hand inside far enough to reach the liquid contents. I placed an 18ga metal needle on the end of a 5cc syringe and punctured the hose of the sprayer. I drew a whole 5cc's of fluid out of the hose and put it directly into a new blood tube. I marked the tube in the same manner as I did the first.

Example: RB002

I discarded the sharps and the syringes in the same manner as before. Note: I changed my latex gloves before each sample was collected. I took photographs of the samples I took and took them to the evidence room for booking.

I took my evidence including these samples to the State Crime Lab the first working day following the fire. I told the Lab Technician how I had collected the samples. She commented that it was a great way to collect and preserve this type of evidence. She had never seen it done before. I took what she said to heart and felt that my new way of doing this could be beneficial to other investigators.

I have listed some key points of this system below. These are somewhat basic but, necessary in maintaining the integrity of the samples.

• Select only red top blood tubes and verify the label reads: "No additives."
• Select different size syringes to accommodate the different size quantities of liquids you will need to collect.
• Select large bore needles and angio-catheters to avoid clogs while collecting samples.
• Puncture the tops of your blood tubes no more than once per tube.
• Try to put your puncture in the top of the blood tube in a routine and uniform place.

Example: Puncture mark near the edge of the top on the side with the label on the midline of the label.

• Change your gloves, syringes, angio-catheters and needles between each sample.
• Maintain the upright position of the blood tubes containing samples.
• Make an evidence seal on the top of the blood tubes to prevent their being opened.
• Dispose of all of your collection equipment to avoid reuses and accidental cross-contaminations.
• Document each step in your report. Specifically include these items and the chain of evidence in your documentation to maintain the samples' integrity.

You may have some personal modifications to these procedures that may enhance your collection of the liquid samples. Some may choose to keep and package their collection equipment separately, in case opposing Council wants to examine it. I don't believe this is necessary. All of the equipment listed here is engineered to be sterile for medical use prior to being unpackaged. Sterile techniques should be used when removing the syringes and needles from the packages. This along with changing gloves should eliminate any doubt of cross-contaminated samples.

Another advantage to using this equipment in sample collection is, it eliminates the need to find, purchase and certify special bottles and jars. This equipment is pre certified, inexpensive and only your closest ambulance away in a pinch. Some Departments already have and store this equipment. It is small and fits in your vehicle nicely.

I encourage any investigator or crime scene technician to implement this method of collecting and preserving liquid evidence. I hope you find it to be beneficial in eliminating some of your worries when dealing with your integrity and chain of the evidence.