Odor work borrows words from cleaning, restoration, HVAC and painting. A written scope might mention source removal, encapsulation, hydroxyl generators and dwell time in a single paragraph. Knowing what each term means makes it easier to compare two scopes, ask sensible questions and describe the work accurately if a buyer asks.

The definitions below are general. Products and procedures vary, so ask any provider to explain how a term applies in their specific plan.

Treatment terms

Source removal
Taking out the material that produces or holds the odor, such as soaked pad, stained drywall or a dead animal. Usually the most effective single step.
Deodorization
A general word for reducing odor. On its own it says nothing about method; ask what is actually being done.
Encapsulation or sealing
Coating a surface with a primer or sealer designed to lock in residual odor and stains after cleaning.
Thermal fogging
Heating a deodorizing solution into a fine fog that penetrates where smoke has traveled. Often requires the space to be empty and may leave a scent.
Hydroxyl generator
Equipment that produces hydroxyl radicals to break down odor compounds in air. Providers describe it as usable around people; ask about its use in your case.
Ozone generator
Equipment that produces ozone to oxidize odor. Ozone is a lung irritant, so the space must be unoccupied, and it can affect some materials.
Chlorine dioxide treatment
A controlled gas treatment used to oxidize odor compounds in an empty, closed space, followed by ventilation before re-entry.
Dwell time
How long a product or treatment must remain in place to work before cleanup or ventilation.
Re-entry
The point at which people can safely return to a treated space, as determined by the provider and the product label.

Building and listing terms

Subfloor
The structural layer under finished flooring, usually plywood, OSB or older plank boards. Liquids that soak through carpet often end up here.
Tack strip
Wood strips with angled pins that hold wall-to-wall carpet at the room edges. They absorb liquid and are usually replaced with the carpet.
Vapor barrier
A plastic ground cover in a crawl space that limits moisture and soil odor rising into the house.
Return air
The path by which the HVAC system pulls air back from the house. An odor near a return can spread through the whole system.
Efflorescence
White, chalky mineral deposits on concrete or masonry, a sign that water has moved through it.
Third-hand smoke
Tobacco residue left on surfaces and in dust after smoking stops, which can continue to release odor.
Pre-listing inspection
An inspection ordered by the seller before listing to find issues before a buyer does.

General information for the Denver area, not a quote or professional advice. In an emergency, call 911.