Equivalent of thermal insulation for odor/smell?

Thermal insulation expresses the capacity of a material or structure to prevent heat from being transferred from one location in space to another (other definitions exist). Thermal is an adjective.

The equivalent for sound is simply sound insulation, though I didn't find sound (as a vibration of the air) as being defined (in a dictionary) as an adjective, but it is here, isn't it?

What is the equivalent of thermal insulation for odor? Simply odor insulation, or maybe smell insulation? As for sound, I didn't find odor defined as an adjective. So should one maybe say odoriferous insulation? odoriferous is an adjective but it usually refers to something with a bad smell which isn't particularly what I want to express: odor transferred can be neutral, pleasant or not.

Usage examples:

• Thermal insulation of this hotel room is good.
• Sound insulation of this house is poor.
• Odor insulation of that room is surprisingly poor (?)

odor proofing

Example (1959) These might be listed as follows ... 2.Odor proofing materials and articles made therefrom...

Example (1960) ...germ, mildew, mold, odor, and fungus proofing of textiles, paper, clothing, shoe linings, blankets, mattresses, and household and personal ...

(2018) Furthermore, if the lid became chipped, insect and odor proofing would be lost. Appropriate Technology in Vector Control

(1952 ) ...shipped in liners which are dirt-proof, dust-proof, odor-proof and must... Material Handling Engineering

Airtightness fits perfectly [per calocedrus comment I retract this word] I believe since, as has been pointed out, odors travel through air.

Presumably, airtightness comes from the word airtight, adj, which Merriam- Webster defines as:

impermeable to air or nearly so, e.g. an airtight seal

I found this references on a company website describing one of their attic insulation services:

Airtightness is primarily focusing on the elimination of all unintended gaps and cracks on the external envelope of the building. [Building systems company website]