Is it safe to breathe around a polyurethane foam mattress as it ages?

What's actually in it

A memory foam or polyurethane mattress is built from a soft polymer that contains leftover isocyanates, polyols, flame retardants, and antioxidants. New foam releases a mix of VOCs that most people recognize as "new mattress smell." That obvious phase usually passes in a few weeks with airing out. What's less obvious is that the foam keeps breaking down slowly as it ages, producing small amounts of formaldehyde, acetaldehyde, and acrolein for years.

Eight hours of sleep means your face is close to that foam for a third of your life.

What the research says

A 2026 kinetic study in Polymers measured autoxidative VOC formation from polyurethane foam over time. The off-gassing followed a slow decay curve, not a sudden drop-off. Formaldehyde, acetaldehyde, and acrolein kept releasing years after manufacture. These chemicals irritate airways and, with long exposure, track with lung problems.

A natural latex or wool mattress skips polyurethane and flame-retardant chemistry entirely. Those are expensive, so an in-between is to use a GOLS or GOTS certified organic mattress topper (cotton, wool, or natural latex) over an existing foam mattress. That puts natural fiber between your face and the foam. Running a HEPA purifier in the bedroom helps too. Crack a window most nights.