Mold in Mattress: Clean It or Throw It Out?

Mold needs moisture and something to feed on. The EPA says moisture is the most important factor influencing mold growth indoors, and lists cloth among the organic materials mold uses as food. A mattress has fabric, padding and the dust that collects in both.

Common moisture sources:

• Humid rooms. NDSU Extension says mold growth is likely where humidity levels above about 70% persist. The EPA recommends keeping indoor humidity below 60 percent (ideally between 30 and 50 percent).
• A bed against an outside wall. NDSU notes there is a chance mold might be growing behind furniture, particularly against an outside wall.
• Spills, accidents and cleaning that soaked into the padding and never fully dried.
• Leaks, AC condensate problems and floods.

Texas makes this harder, especially in the east. The Gulf is the primary source of moisture, which is most readily available to the eastern part of the state.

• Spots. UF/IFAS Extension describes mildew as black, brownish, or reddish fuzzy discoloration with a musty odor.
• A musty smell that won't air out. NC State says that if a mattress has a musty odor after drying, mildew is present.
• Damp or discolored patches on the underside or on the box spring. Flip the mattress and check the bottom and sides, not only the top.
• Spots on the slats or frame under where the mattress sits.

If you find mold on the mattress, check the rest of the room too: the wall behind the headboard, the window, the closet and any AC vents. Our signs of mold in house guide has a checklist.

Sometimes. The deciding question is whether the mold is on the surface or inside.

Mold in a mattress: clean or replace?

The reason is the same one that applies to carpet and drywall. The EPA explains that molds will infiltrate porous substances and grow on or fill in empty spaces or crevices, so the mold can be difficult or impossible to remove completely. And killing it isn't enough: the EPA says dead mold may still cause allergic reactions in some people.

NC State adds one more warning: sanitizing can kill existing mold, but mold will return unless the materials are completely dry inside.

These steps combine University of Georgia Extension's mattress guidance with Texas A&M AgriLife's mildew steps for household articles and upholstery.

Protect yourself first. Wear gloves, goggles and an N95. The CDC recommends at least a NIOSH Approved N95 respirator and says not to touch mold with bare hands. If you have asthma or mold allergies, let someone else do this.

1. Take it outside and brush it

UGA says to remove loose spores by brushing with a soft-bristled broom, outdoors if possible, to avoid scattering spores in the house. Wash the broom afterward.

2. Vacuum the surface

Vacuum to draw out more mold. Texas A&M recommends using a HEPA vacuum, if available, to remove visible mold growth and discarding the bag. With a regular vacuum, empty it outdoors: UGA notes that mold spores are being drawn into the bag of the vacuum cleaner.

3. Dry it in sun and moving air

If the mattress is damp, UGA suggests drying it with a fan and heater, and if possible placing it in direct sunlight and air to stop mold growth. NC State's drying advice for a salvageable mattress is to set it right-side-up in the sun on blocks and use a fan to speed drying.

4. Wipe the stain with diluted alcohol

UGA and Texas A&M both suggest wiping the stain with a cloth dampened in 1 cup rubbing or denatured alcohol to 1 cup water, then drying thoroughly. Dampen, don't soak.

Test on a hidden spot first. UGA warns that alcohol will damage acetate, triacetate, modacrylics and acrylic fibers, and that overwetting upholstery fabric can leave a ring.

5. Dry again and watch it

Let the mattress dry completely, in the sun if possible, before you put sheets back on. Then check it for a week or two. If the spots or the smell come back, the mold is inside and the mattress needs replacing.

What not to do: don't pour bleach on a mattress. Bleach doesn't fix porous materials, and the EPA says bleach is not recommended as a routine practice during mold cleanup. Never mix cleaners. Our vinegar vs bleach for mold guide explains why.

Wood bed frames and slats

Wood is easier to save than a mattress. Clean finished wood with detergent and water, then dry it slowly. Texas A&M advises drying furniture slowly out of direct sunlight because sun will warp furniture. NC State notes mildew may keep growing on a wood frame until the moisture content of the wood drops below 20 percent or less. For mold that has gone into the grain, see our mold on wood guide.

Metal frames and bedsprings

NDSU says wire bedsprings can be cleaned at home: wash them thoroughly, dry in sun and air until odors are gone, then protect them with rust-preventing paint.

Box springs

A box spring is fabric over wood and springs, so it behaves like a mattress. NDSU says upholstered box springs may not be worth the cost of new covering and padding materials. If one sat in floodwater, replace it.

Sheets, blankets and washable mattress pads go in the laundry. Our mold on clothes guide covers bleach, stains and musty smells in fabric. UF/IFAS suggests putting musty bedding in the sunshine for several hours as a first step.

Pillows are harder. NDSU says pillows, while washable, usually should be discarded if soaked with contaminated floodwater.

After a flood, the answer is almost always to replace the mattress. The EPA says to throw away anything that was wet with flood water and can't be cleaned and dried completely within 24 to 48 hours. University of Georgia Extension says to get rid of porous items exposed to floodwater, including mattresses, furniture, stuffed toys and pillows. Kentucky Extension agrees that most porous items that can absorb moisture (such as couches, mattresses, and pillows) should be discarded.

Photograph the mattress and its label before it goes to the curb. Texas A&M advises taking photos for use as an inventory and keeping damaged materials for proof of loss. See mold after flood Texas and does insurance cover mold.

• Control humidity. TDLR suggests keeping humidity no higher than 50% all day, with an air conditioner or dehumidifier. A dehumidifier for mold helps in a bedroom that stays damp.
• Let air reach it. Museum conservators advise against storing collections directly against outside walls, where humidity and condensation are higher, and recommend a fan for circulation. The same logic applies to a bed: a few inches of space from an outside wall helps.
• Dry spills right away. If wet materials are dried within 24 to 48 hours, mold usually won't develop, according to the EPA.
• Fix the room. Window condensation, a wet wall or a leaking AC line will keep re-wetting the bed until it's fixed.

The EPA says mold exposure can lead to asthma attacks, eye and skin irritation, and allergic reactions. If you've been waking up congested or wheezy, replacing a moldy mattress makes sense, but a doctor, not a mold test, decides whether mold is the cause. The CDC says individuals with persistent symptoms should see their physician. Our mold allergy guide covers symptoms.

If a new mattress gets moldy too, the room has a moisture problem. A licensed mold testing company in Houston (or Austin, or your city on our Texas page) can find hidden moisture and mold. If walls or floors need cleanup, a separate mold removal company does that work, because Texas law says a license holder may not perform both mold assessment and mold remediation on the same project. Confirm licenses with our license check tool.