The first accelerant detection canine (ADC) was Mattie, a Labrador retriever trained by the Connecticut State Police with assistance from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), to respond (alert) to 17 different odors of ignitable liquids in 1986. This pilot program led the way for ATF’s Accelerant Detection Canine Program. The program trains dogs to detect a variety of ignitable liquids that could be used to start a fire.

This is all possible due to the dog’s incredible sense of smell. According to Forensic Science Central, the average human being has roughly 5 million sensitive cells within the nose. This appears to be a large number, until compared with the 200 million cells in the average dog’s nose. Further increasing the canine’s sense of smell is an organ (Jacobson’s organ) in the roof of the mouth that is not present in humans. This organ essentially allows the dog to “taste” a smell, thus strengthening its ability to detect odors. Canines detect odors directly from the source or from residual scents, odors which persist in an area after the original source is no longer present.

James Walker, former director of the Sensory Research Institute at Florida State University states that a dog’s sense of smell overpowers a human’s own by orders of magnitude — it’s up to 100,000 times as acute.

Alexandra Horowitz, author of “Inside of a Dog,” says that dogs can detect some odors in parts per trillion! She explains that a human might notice if his or her coffee has a teaspoon of sugar in it; however, a dog could detect a teaspoon of sugar in a million gallons of water, or two Olympic-size pools.