Odor Hygiene at Nosework Competitions

Odor hygiene refers to properly handling target odor, so you know with certainty where odor is located, and where it is not located. Good odor hygiene enables more teams to succeed. It’s a really important component of holding successful scent detection trials, where every participant has a role to play. This post will outline some unique considerations for ensuring reliable odor hygiene at scent detection trials so you can be prepared in advance.

Ever give your dog a bath after being skunked? Washing your hands or applying antibacterial hand gels after you touch odor does not remove all of the odor. When in doubt, do not touch any objects!

What’s the big deal? Volunteers are the lifeblood of events. Clubs can’t hold scent detection events without volunteer support. But even if you follow perfect odor hygiene at home, scent detection competitions introduce complexity and increase the chance of errors. Blind searches mean that you can’t label objects. Hot objects (with odor) look exactly like cold objects (without odor)! You won’t know which is which, unless you ask. It’s a recipe for potential mistakes. To minimize mistakes, knowledge is the first step.

Hopefully, all competitors at a nosework competition start with cold hands (no odor). Competitors are not allowed to bring scent to the venue, but that’s not the only way to end up with hot hands. Once you handle anything with odor, you have hot hands for the duration of the event. For example, if your dog destroys a hot box in the warm-up area, when you pick up that hide you have hot hands that can contaminate whatever cold boxes, light switches, chairs or objects you touch in future.


The judge needs to know where odor is, and where it isn’t. This makes it possible to tell competitors who call an alert whether they are correct or incorrect. If there are odor hygiene mistakes (such as a hide left from the last scent event), you may think the dog is false alerting, when really they’ve found an old hide. This is very confusing to the dogs.

Only one or two people should be handling hides, and they must wear gloves. If you haven’t been instructed to move items in the search area, don’t contaminate the search areas by touching or moving any objects, since you don’t know which are hot and which are cold.

An experienced hide official/certifying official (or delegate) is responsible for assembling and placing all the hides. They should make a numbered list of hides, identifying odor(s) present, vessel composition e.g. tin or box, location, and aging. All the hides should be labelled. At the end of the search the hide official/certifying official (or delegate) will pick up all of the hides using gloves and forceps or tweezers, and verify each against the list. The number of hides placed = the number of hides picked up at the end of the day. That way no hides are lost at the venue.

Once you handle a hot box, you can’t supply a distraction for the judge because distractions need to be free of odor! Hot and cold must always be kept separate! Please do not carry or store hot and cold items next to each other. For example, do not store extra hot boxes next to the search area, and then expect dogs to ignore the huge cloud of odor.

Scent (including hot boxes, kits, hides and odor) must only be:

  • INSIDE hides placed in the search area
  • Held by hide official or delegate with hot hands and gloves (not placed on a table or the floor)
  • Inside labelled self-serve warm up boxes for competitors outside the building
  • Inside designated scent room that with a clear “do not enter” odor room sign or inside the judge’s or organizers’ vehicle (inside airtight containers)

Please do not move or store hides or hot boxes anywhere else, or they may contaminate other areas that the judge won’t know about. If a box in a search is damaged, don’t just move it to the side of the room where a search is being conducted. A person with hot hands needs to move it to the odor room and bring a replacement hot box to the search area.

Never move hot and cold items together e.g. don’t transport hot and cold boxes together in your arms to move them. Never store distractions or cold items close to hot items e.g. do not put a bunch of hot boxes next to a bunch of cold or distraction boxes.

For helpers touching hides (e.g. if a dog demolishes a box and the hide is thrown clear), please be aware that everywhere you and the hide touch spreads odor and may cause dogs to false alert. Once a container search is done, be careful to move the hot containers directly to the odor storage room, without touching any surfaces on the way.

If you wipe a hot box with a paper towel, then wipe a cold box, you may contaminate the search area. If you throw your hot paper towel or gloves away in a garbage and that room is later used in a search, the odor will be detectable and some dogs will false alert there. All gloves and hot garbage needs to go into the designated odor room e.g. in the laundry room for this weekend’s trial.

Separate host club volunteers with cold hands should handle everything else. One of the most common errors clubs make is for volunteers who have touched odor (with hot hands) will then touch tape that is used on the start line, contaminating it and causing false alerts. Also, beware where you store and transport the hot boxes and odor kit. Many times the scent kit is left open where its intense odor plume is detectable from the search area. That’s not supposed to be part of the test. There should only be the set number of hides in the search area, no extras you assume the dogs will ignore.


All competitors should have cold hands. Do not bring odor to the trial venue. Please do not touch any item in the search area, or drop food, or you contaminate the search area, making it more difficult for subsequent teams. (Note that dogs are allowed/expected to touch objects in the search area.)

Hopefully, the host club will provide competitors with labelled warm up boxes (outside the building). Be aware that if your dog retrieves the hide and/or destroys the box or you touch inside the box, and you touch the hide, you have hot hands for the duration of the event. Anything you touch after that will be contaminated with odor. If the box needs to be fixed, let the hide official know so they can correct the problem.

The host club’s trial organizer is responsible for bringing cold distractions and markers to delineate search areas. Cold supplies should include:

  • Gloves
  • Well ventilated, clean containers to insert distractions
  • Distractions e.g. toys and food such as crackers, bread, celery, lettuce (for the higher levels as directed by the judge)
  • Cold magnets to test whether a potential hide location is magnetic. Once the cold helper is done testing, (s)he will advise the judge accordingly so the judge can place the hide without moving it repeatedly and contaminating the surface
  • Tape, chalk and pylons to mark start lines and clearly delineate search areas, as directed by the judge.
  • Tape measure
  • Pee/poo cleanup supplies
  • Paper towels
  • Duct tape, scotch tape, glue dots, etc.

Volunteers with cold hands must never touch any odor, kit, hide, or hot boxes. Do not go into rooms where odor is stored (they should be clearly labelled).

Warning: Set Up and Take Down Are Riskiest

During cleanup and takedown, be very careful to avoid mistakes when everyone is tired and wants to go home. First, the hide official should remove the hides from all the search areas. Do not handle any items in a search area until the hot items have been removed. For example, if you clean up after a container search by carrying all the containers, or putting them together at somebody’s vehicle then you may be mixing hot and cold containers together, contaminating all of them with scent. If you store hot items and cold items inside your vehicle, they all become hot inside that confined airtight space. If a hide falls out of a container, it will contaminate the floor or surface it falls upon. If you leave a hot item at the venue, it contaminates that area and may be unexpectedly found by dogs in future.

In conclusion, it’s very important for every participant at a nosework competition to know whether she has hot hands or cold hands, so we can keep odor where it’s supposed to be, not contaminating or confusing the integrity of the search areas. Together, we can prevent or minimize mistakes.  As always, nosework competitions begin with a judge’s briefing where you can ask any outstanding questions, and we’ll do our best to set you up for success.  Let’s have some fun enjoying sniffing together with some great scent dog detection teams!

2 thoughts on “Odor Hygiene at Nosework Competitions”

  1. Awesome article. Thank you for explaining “hot hands” as I’ve seen students “make the boxes neat” when they’re done, or “put a tin back” if their dog accidentally moves it!

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