LIFE HACKS

How to Remove a Musty Smell From a Bathroom Cabinet

Remove a musty smell from an under-sink bathroom cabinet by finding moisture, drying the space, cleaning hard surfaces, and knowing when to call for help.

By Wishsmith ยท Published September 22, 2026

A musty smell in an under-sink bathroom cabinet usually points to trapped moisture, a small plumbing leak, damp items, or a porous shelf that has absorbed water. Empty the cabinet, check the pipe joints and cabinet base, then dry and clean the space before putting anything back. Do not cover the odor with air freshener or pour an aggressive cleaner into the cabinet. If the base is swollen, the smell returns after drying, or you see widespread mold, stop the DIY cleanup and contact your landlord, a plumber, or a qualified remediation professional.

Find the moisture before cleaning

Start with the cabinet completely empty. Put toiletries and cleaning products on a towel outside the bathroom, and discard wet cardboard packaging. Look at four areas:

  1. The pipe connections. Run a dry paper towel around the shutoff valves, supply lines, drain trap, and the point where the drain enters the wall. A damp streak on the towel suggests an active or recent leak.
  2. The cabinet floor and back wall. Check for darkened patches, soft spots, peeling laminate, swollen particleboard, or a water line. Press gently with a gloved finger; do not dig into a damaged surface.
  3. The shelf and stored items. Shampoo bottles, cloths, sponges, and spare toilet rolls can hold moisture against the cabinet. Smell each item separately so you do not mistake one damp object for a whole-cabinet problem.
  4. The surrounding wall and floor. A dry cabinet can still smell if water is entering from the wall, skirting board, or bathroom floor.

If a pipe is actively leaking, place a bowl under it only as a temporary measure and contact the responsible repair person. In a rental, photograph the leak and damage and notify the landlord or property manager rather than removing fixed plumbing or cabinetry yourself. A recurring leak needs repair; cleaning alone will not solve it.

A safe DIY reset for a dry, intact cabinet

Use this method when there is no active leak, the cabinet is structurally sound, and the odor is mild.

1. Remove moisture-holding materials

Take out shelf liners, cardboard, fabric bags, paper products, and anything visibly damp. Wash reusable plastic containers separately and let them dry fully. Replace a liner that is peeling, stained through, or still smells after washing. Do not put items back while they are even slightly wet.

2. Dry the cabinet with controlled airflow

Leave the doors open and wipe standing water with a clean towel. Position a fan outside the cabinet so it moves room air across the opening without blowing dust directly into the plumbing or electrical fixtures. Use ordinary room-temperature airflow rather than a hair dryer, heat gun, or space heater; concentrated heat can damage finishes and creates an unnecessary fire risk in a crowded bathroom.

Keep the cabinet open until the shelf, corners, pipe cutouts, and back panel feel dry. If the room is humid, run the bathroom exhaust fan as intended and keep the bathroom door open after use. For guidance on keeping the fan cover clear, see how to clean a bathroom exhaust fan cover without opening the unit. Never open an electrical fan housing as part of this cabinet job.

3. Clean hard surfaces with one mild method

For sealed laminate, finished wood, plastic, or metal, mix a small amount of ordinary dish detergent with warm water. Dampen a cloth rather than pouring liquid into the cabinet. Wipe the shelf, side walls, door, and accessible pipe surfaces, then wipe again with a clean damp cloth to remove soap residue. Dry every surface immediately.

Use a separate cloth for the cabinet and for the bathroom floor. Do not mix bleach with ammonia, acids, or any other cleaner, and do not combine products in a bucket. Read the label if you choose a commercial cleaner, ventilate the room, and keep products away from children and pets.

EPA guidance says mold can be scrubbed from hard surfaces with detergent and water, followed by thorough drying. That does not mean every porous cabinet panel can be restored. If mold has penetrated particleboard, cardboard, insulation, or another absorbent material, replacement or professional advice may be safer than repeated scrubbing.

4. Let the smell test come last

After the cabinet has dried, close the doors for a few hours and check the odor again. If it is gone or much weaker, return only clean, dry items and leave a little space around the plumbing. If the smell is still strong, smell the empty cabinet and each removed item separately. A wet sponge, fabric pouch, or bottle stored on its side may be the source.

Prevent the smell from returning

Keep the cabinet organized around airflow and leak visibility rather than maximum capacity. Store bottles upright in a shallow, washable tray, leave the pipe joints visible, and avoid placing paper products directly on the cabinet floor. Wipe condensation from bottles before storage. Do not use the cabinet as a drying space for cloths, bath mats, or cleaning rags.

After a hot shower, use the exhaust fan or open a window when safe and practical. The EPA notes that bathroom ventilation and faster drying help limit recurring mold in damp areas. If you use a hygrometer, CDC guidance recommends keeping indoor humidity no higher than 50% all day; a dehumidifier can help when the room stays damp.

For a related bathroom cleaning task, see how to clean soap scum from a glass shower door safely. Reducing moisture at the shower and improving airflow can support the cabinet fix, but it cannot replace plumbing repair.

Common mistakes to avoid

When DIY is no longer the right job

Stop and arrange help if water keeps appearing, the cabinet base is soft or collapsing, the wall or floor is damp, sewage or contaminated water was involved, or mold covers more than roughly 10 square feet. EPA also recommends professional advice when HVAC contamination is suspected or when health concerns make cleanup unsafe. People with asthma, significant allergies, chronic lung disease, or a weakened immune system should ask a health professional about their situation before cleaning moldy areas.

A mild odor from a dry, intact cabinet can often be handled with inspection, controlled drying, and careful cleaning. A recurring musty smell is useful information: find and fix the moisture source, then decide whether the material can be cleaned or needs a qualified repair.

A 15-minute cabinet check

Once the cabinet is dry, set a timer for 15 minutes. Spend five minutes checking every pipe joint with a dry towel, five minutes removing anything damp or expired, and five minutes arranging the remaining items so the base and connections stay visible. Write down any wet spot that returns and report it instead of repeatedly wiping it away. The goal is a cabinet that stays dry and inspectable, not one that merely smells better for an afternoon.

Sources and further reading