Is it safe to run scented air fresheners in homes with active mold or mildew?

What's actually in it

A home with a mold issue (damp basement, leaking bathroom, poorly ventilated attic) has mold spores and mycotoxins in the air. Adding a scented air freshener introduces terpenes, fragrance chemicals, and solvents into the same air. These don't neutralize each other. They react to form new secondary pollutants: formaldehyde, ultrafine particles, and novel oxidation products.

Masking the mold smell is a way of telling yourself the problem is gone when it isn't. Fixing the mold is the actual solution.

What the research says

A 2026 study in J Hazard Mater looked at toxicological interactions between biotic and abiotic components of indoor air: mold and air fresheners. The combination produced worse air chemistry than either source alone. Secondary chemistry from the interaction drove much of the harm.

First priority: find and fix the mold source. Damp walls, leaking pipes, poor ventilation, or flooding history all need structural fixes. A dehumidifier keeps the air below mold-friendly humidity (under 50%). For the smell, a HEPA air purifier with activated carbon removes both mold spores and chemical residues without adding new chemistry. Plain baking soda and unscented cleaning also help. Air fresheners in a moldy home make everything worse.