How to Tell If Your Used Crib Mattress Is Safe

baby sleeping in crib

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Babies are adorable and tiny, but can also be very expensive. There is a lot of gear to buy, including a crib mattress. If you have access to a used one, you may wonder if it's safe to use or if you should buy a new one.

A crib mattress can cost several hundred dollars, so it's very tempting to simply reuse your older child's mattress for a new baby or purchase one secondhand. However, a used crib mattress (even if it was used by a sibling, close family member, or friend) might not be as safe as you think.

Is Your Used Crib Mattress Safe?

A baby’s mattress must be firm. Soft mattresses are associated with an elevated risk of sudden infant death syndrome (SIDS). Over time, the surface and shape of a crib mattress can settle and become soft and uneven. Reinforced edging (which stops the edge of the mattress from caving down under your baby’s body weight) can also weaken with time.

Without a firm edge, your little one could become trapped between the mattress and the crib rails, which could result in injury or even death.

However, if you purchased the mattress new for an older sibling, you might be able to reuse it. It is safe for your baby if it is clean, in good condition, and meets these safety standards.

Proper Fit

Mattress size matters. Most cribs use a standard-sized crib mattress, but you will also find those that do not. An ill-fitting mattress can pose a serious safety hazard for your child.

To see if your potential mattress is a good fit, try the "two-finger" test. There should be no more than two finger-widths of space between the side of the mattress and the crib frame. Any larger and your baby could become entrapped between the two, resulting in injury or suffocation.


The mattress surface should appear firm and even. If you notice any sagging or signs of body contouring, the mattress poses a risk for SIDS and should be replaced.

To test a mattress's firmness, press your hand into the center and around the edges of your mattress. When you remove it, note how quickly it regains its shape. A firm and resilient mattress will snap back quickly.

Frame Integrity

The overall frame of your mattress should be in good repair. If you find any evidence of a broken frame or support bars, the crib mattress should be replaced. Additionally, if the mattress rattles when moved or if you can feel the springs sticking up through the cushioning, do not use the mattress.

A Clean Record

Just because a mattress looks clean does not mean that it is clean. Experts often advise against using a secondhand mattress because you don't have intimate knowledge of its past. Even a close friend or family member might fail to mention an accident or two—especially if the mattress appears no worse for the wear.

Be sure to inspect the mattress for bed bugs, small, flat, reddish bugs that subsist on blood. These tiny creatures are experts at staying hidden during the day, so look in the mattress seams and any other possible hiding places near the bed. If you do find bed bugs, it's best to pass on the mattress. If you already own the bed, it's usually best to call an exterminator.

Additionally, check the mattress for signs of mold. Crib mattresses are often covered in a waterproof coating, making mold less likely. Mold commonly grows in damp, wet, or humid conditions, so if the mattress (or room it is in) has been exposed to moisture for an extended period, it may have mold. Even if you don't see mold, it could be there. A musty odor is a telltale sign of mold or mildew, which in the initial stages of growth may be invisible to the naked eye.

That said, no one knows your mattress’ history better than you. If you decide to reuse a mattress, even if it looks clean, be sure to thoroughly clean it by wiping it down with soap and a damp cloth.

If you’re planning on reusing your existing crib mattress, be honest with yourself. If it ever experienced a good soaking or has any unpleasant odors, you probably shouldn't use it.


Any crib mattress that you use needs to be able to withstand a thorough inspection. If it does, cover and store it in a clean and dry place while you await its next occupant. Once in use, invest in a water-resistant mattress cover, and don’t forget to conduct regular inspections to ensure your little one’s mattress is holding up.

A Word From Verywell

While it can be tempting to reuse a crib mattress or purchase one secondhand, you should only consider a used mattress if it meets the above guidelines for safety and cleanliness. It's important to make sure whatever mattress you choose is still in good shape so that it's safe for your baby.

5 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Pediatrics. How to keep your sleeping baby safe: AAP policy explained.

  2. Consumer Product Safety Commission. Safety standard for crib mattresses. Federal Register.

  3. Consumer Products Safety Commission. Safe sleep: Cribs and infant products.

  4. Centers for Disease Control and Prevention. Bed bugs FAQs.

  5. The Sleep Foundation. Mold in the bedroom.

By Kitty Lascurain
Kitty Lascurain is a journalist with over a decade of experience writing about parenting, travel, and interior design.