Which crib mattresses are actually free of fiberglass and flame retardants?

A crib mattress is the one product your baby is in contact with for most of the day, every day, for years. These are the checks that actually separate a clean mattress from one that just markets itself that way, in the order we would work through them.

1. Check what stops the fire

   Every crib mattress has to pass an open-flame test, but how it passes is the whole story. Wool, organic cotton, or a plant-based (PLA) barrier do it cleanly. Fiberglass and added flame-retardant chemicals do it in ways that end up against your baby. If a brand will not name its fire barrier, or the cover says "do not remove," treat that as a likely fiberglass sock.

2. Find out how it is made waterproof

   Waterproofing is where hidden chemistry lives. Food-grade polyethylene or TPU is the clean way to do it. A vague "water-repellent treatment" with no published chemistry is the warning sign, since that is where PFAS can hide on a surface your baby sleeps on nightly. No waterproofing at all is fine too, as long as you add a breathable, food-safe protector.

3. Make sure the infant side is firm

   Safe-sleep guidance is clear that infants need a firm, flat surface. A mattress that feels plush or soft raises the suffocation risk for a newborn. A two-stage mattress gives you a firm infant side that flips to a softer toddler side later, which is the safest way to get years of use from one mattress.

4. Look for a real certification, not just a logo

   GREENGUARD Gold confirms low chemical emissions for a baby room, and GOTS or GOLS confirm organic materials. The catch is that a logo is not the same as a live certification. At least one mattress we looked at displays a certification mark that independent reviewers could not verify, so check that the certificate is real, not just printed on the listing.

5. Confirm it fits the crib

   A mattress that is too small leaves a gap a baby can roll into, which is a real suffocation and entrapment hazard and the reason behind recent recalls. A standard full-size crib mattress should leave no more than two fingers of space on any side. Avoid undersized aftermarket mattresses for non-standard cribs.

6. Decide if you want breathable

   A breathable, washable core lets a face-down baby draw more air than a conventional surface. It is a genuine safety bonus, not a requirement, since a firm flat mattress is the primary control either way. If you want it, the Newton and Lullaby Earth Breathe Safe are built around it.