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The Sniff Test: Ozone Scent Control vs Drug-Sniffing Dog

Ultimately, ozone couldn't fool our K-9 cop's nose—but it confused the pooch for longer than anything else we've tested
Rows of boxes, one with a hunter in it, and a dog looking for him.
(Photo/Ralph Smith)

The Sniff Test: Ozone Scent Control vs Drug-Sniffing Dog

Editor’s Note: Back in the spring of 2009, our late, great whitetails columnist Scott Bestul had the brilliant idea of enlisting the noses of drug-sniffing dogs to help shed light on a buck’s ability to detect human odor, as well as our ability to hide it using scent-control products. Knowing that a whitetails nose is often compared to a dog’s—and has at least as many and probably more olfactory receptor sites—he set up a series of tests. You can read the first here. The second here. The third here. And below is the fourth and final test.

YOU'VE HAD YOUR head in the clouds if you’ve missed the de-scents-itizing hype of companies selling ozone-generating products. Ozone, they claim, contains an extra oxygen molecule that attaches itself to other molecules—say, b.o. molecules— and changes their structure. I’m eager to examine any deer hunting trend and, if necessary, flip it on its head. So I enlisted Chance, a highly trained police dog, to test ozone’s effectiveness.

I’ve watched Chance’s nose zip through every sort of no-scent solution and was fully prepared for an ozone rout. But that’s not exactly what I got. As a refresher: Our scent tests are set up just like the training exercises used by K-9 officers. In the box test, police dogs are taught to find a “bad guy” hiding in one of six square boxes, spaced evenly across a large field. First, I sat in each box for a full minute, leaving behind a trace of human scent. Then it was up to Chance to find the member of my test team (hunting buddies Bob Borowiak, Tony Houdek, and Tom VanDoorn; and my father, Marv) who had climbed into one of the boxes. To start each trial, the handler took Chance off the leash, then ordered: “Find him!” At this command, I started my stopwatch and timed how long it took Chance to bust the hunter.

Test No. 1: No Scent-Control Control

A close-up portrait of a German Shepherd's face.
A dog's nose has more than 220 million olfactory receptor sites. A whitetails is thought to have several hundred million. A human's has a paltry 5 million. (Photo/peopleimages.com via Adobe Stock)

The Setup: As a control test, Houdek jumped in a box, wearing street clothes.

The Result: Chance barked at his box after only 14 seconds.

Analysis: Dogs performing this drill are marked down if they bark at the wrong box, so it’s not unusual for them to check every one—even if they get a strong whiff at one of the first. Chance’s head snapped around as soon as he passed Houdek’s box, but he checked every box before racing back. Had he reacted immediately to that first scent (as a whitetail would have), Chance could have cut this time in half.

Test No. 2: Baking-Soda Bomb

A hunter in camo getting baking soda poured over his head.
No amount of baking soda seemed to be enough to hide the hunter's odor from our K-9 cop. (Photo/Ralph Smith)

The Setup: To assess how a classic scent-control method would fare, VanDoorn, an expert whitetail hunter who swears by baking soda, took a shower in no-scent soap mixed with soda and then dressed in clothes washed in a similar combination, plus powdered with soda. He then rubbed more of it in his hair, on his socks, and in his boots.

The Result: Chance found VanDoorn in 19 seconds.

Analysis: Chance showed no noticeable reaction the first time he ran past VanDoorn, and he checked all six boxes. Even though VanDoorn’s trusted in-the-field system cheated Chance’s nose for a few extra seconds, the difference wasn’t pronounced. I was a little surprised by this, given VanDoorn’s success at fooling deer—but not as surprised as VanDoorn.

Test No. 3: Ozone-Treated Clothing

The Setup: Before the test, my dad took a no-scent shower and placed a Scent- Purge 50, an ozone-generating unit designed to infuse clothing with ozone into a plastic tub that held his hat, boots, and two layers of camo clothing for 30 minutes. Dad dressed in these treated clothes just before entering the box.

The Result: Chance needed 42 seconds to find my dad.

Analysis: The dog ran the entire course twice before marking Dad’s location. Though he did a slight head bob toward the correct box on the first lap, it was clear that the smell of ozone was confusing Chance. This was one of the most dramatic delays of Chance’s success in all the years we’ve conducted these tests.

Test No. 4: Ozonics Unit

The Setup: Borowiak took a no-scent shower and dressed in hunting clothes that he’d washed in no-scent soap. He carried an Ozonics unit (ozonics hunting. com) meant for mounting near a treestand or in a blind, ran it for a minute inside the box before the test began, and left it on throughout.

The Result: It took Chance 50 seconds to find Borowiak.

Analysis: Even the handler was stunned at how long it took Chance to find Bob. Again, the dog ran two full laps before choosing the right box, and his first bark was tentative—like a guess. This was the most shocking result in four years of testing. We’d put Borowiak’s other no scent regimens under Chance’s scrutiny before, and the dog had found Bob almost immediately. Yet the addition of ozone confused that nose for nearly one minute, which amazed everyone.

Nothing—not even ozone—will completely cover human odor. But if you can muddy the olfactory water for 50 seconds, that’s plenty of time for you to get a shot at a monster buck.