Re: Sensitivity Comparison for Ignitable Liquids

On Wednesday, January 23, 1996 the following tests were performed at the offices of “Origin & Cause” in Ancaster, Ontario.

Test Objectives

To try and determine the ability of a dog trained in the detection of ignitable liquids in term of the sensitivity for searching out various dilution’s of an ignitable liquid.

To compare the above sensitivity of the dog to the sensitivity of analyses currently conducted by Passive Fiber sampling and GC/MS at Actlabs Organics.

Test Conditions

  • the office flooring was carpeted. The carpet was greater than 1 year in age and well maintained,
  • the office consisted of a large central carpeted area and several adjoining offices carpeted with the same material,
  • aside from the handler up to eight other people were present,
  • tests were conducted by directly pipeting the water based test solutions onto the carpet,
  • testing was done between 10:45 and 11:45 am,
  • testing was done singly i.e., each test was spotted and then the dog allowed to search the area approximately one minute later, then the next test was spotted. There was about 5 minutes between tests,
  • testing started with the most concentrated sample and proceeded to more dilute concentrations,
  • concentrations were within an error of ~5%,
  • the water used for dilution’s was 18 megaohm Ultrapure Deionized water,
  • non-weathered gasoline and non-weathered low-odour kerosene was used,
  • all searches were conducted by “Smoke”, a German Shepherd,
  • all solutions were kept in a separate office behind a closed door during searches.

A. 1 Part Gasoline : 1,000 parts water (1 : 1,000)
B. 1 : 10,000
C. 1 : 100,000
D. 1 : 1,000,000 (1 part per million or 1 ppm)
E. 1 Part Low-Odour Kerosene : 5,000 parts water (1 : 5,000)
F. 1 : 50 (Gasoline)
G. Odourless Lamp Oil (No dilution)

Method of Spotting

Using a fresh glass pipette for each test, the first spot used 3 drops of solution “F (1) “. This first test did not result in a response from the dog. This area was heavily traveled and was between the boardroom, washroom and near the front entrance which may have been detrimental to the search. It was also discovered that a person in the room had come in contact with gasoline, with their shoes, that morning and had definitely contaminated an area within 5 feet of F(1). It was also felt that 3 drops directly on top of each other might be too small in terms of surface cross-section and/or too small a liquid content to be a realistic test. All subsequent tests used ten drops of the solution spread over a circular area approximately the size of a quarter. The initial solution was re-spotted in a new location using 10 drops at “F(2)”. As an example using this method for solution “B”, ten drops of 1:10,000 was used. Each spot was prepared by one person for consistency.


  • For solutions A, B, and C a positive hit by the dog was made during a mechanical search directed by the handler. These searches became increasingly more difficult for the dog.
  • For solution D, the most dilute solution, it appeared that no positive response by the dog could be made.
  • It was observed that the dog favoured searching the baseboard area where walls and floor meet whereas all spots were located 6″ to 8″ away from the wall.
  • Solution “E” containing Kerosene was located in an office containing a significant quantity of passive cigarette smoke. This search resulted in an immediate positive without any direction from the handler, i.e., a “free” search.
  • Solution “G” was an Odourless Lamp Oil that was on hand. Several people could not smell any odour directly from the opening of the container. Three drops of this clear, colourless solution was spotted on the carpet. A positive hit from the dog was quite easy for this substance.
  • The dog showed a high degree of focus during searches and was not distracted by others in the room aside from the handler.


The dog could detect a concentration between 1:100,000 and 1:1,000,000 of gasoline. Currently Actlabs Organics can detect gasoline at 1:100,000 at approximately five times above the method blank or background.

It is logical that the sensitivity of the dog will vary with different ignitable liquids. In support of this there appeared to be a more immediate detection of 1:5,000 of Kerosene than the 1:1,000 of Gasoline. It is also probably true that different dogs will have different limits of sensitivity.

The comparison of the sensitivity of this dog with the current laboratory analysis is very good and is within a factor of ten. Using these findings, and perhaps an additional experiment with the dog(s), the analysis by Actlabs Organics will be further tuned to try and achieve the same sensitivity as these highly trained dogs and thus be an even better confirmatory test.