Polyurethane Foam

It's the soft, springy foam inside most mattresses, sofas, cushions, and padded baby items. Chemically it's a polyurethane — a polymer made by reacting two ingredient families that lock together as the foam hardens. Once fully cured, the foam itself is fairly stable. The conversation about foam is really about two things: additives mixed into it (especially flame retardants in older furniture) and the temporary smell new foam gives off as leftover manufacturing chemicals escape.

Nothing else delivers soft, durable cushioning this cheaply. Foam can be poured into any shape, made firm or plush, and it bounces back for years. That's why it dominates mattresses, sofas, car seats, and baby gear. Memory foam is the same family, tuned to respond slowly to pressure. Its usefulness is exactly why it's hard to avoid — most homes have foam in nearly every soft surface.

Furniture and mattress tags usually say "polyurethane foam", "polyfoam", "memory foam", or "viscoelastic foam" in the filling description. "PU" or "PU leather" on bags and jackets means a polyurethane coating — related material, different use. Certification logos are worth knowing: CertiPUR-US (foam-specific) and GREENGUARD (low chemical emissions) appear on compliant mattresses and baby products. No tag at all usually still means polyurethane — it's the default filling.

Mattresses and toppers, sofas and armchairs, dining chair pads, cushions, crib mattresses, changing pads, nursing pillows, stroller padding, car seats, office chairs, carpet underlay, and shoe soles. If it's soft and holds its shape, it's very likely polyurethane foam. The items that matter most are the ones you or your baby spend hours against daily — beds, sofas, and feeding pillows.

Three routes. First, new foam off-gasses volatile leftovers from manufacturing — the "new mattress smell" — which fades over days to weeks. Second, additives such as flame retardants don't stay put: they migrate slowly out of foam into household dust, which people (especially crawling babies) ingest. Third, old foam that's crumbling sheds particles carrying those additives. The cured polymer itself isn't the main concern; what was mixed into it is.

The main pregnancy-relevant thread is flame retardants, which research has linked to thyroid hormone changes and developmental outcomes — and a mattress is the single largest foam item you spend a third of your life on. That said, modern certified foams contain far less of the older flame-retardant chemistry. Practical version: if you're buying a mattress or nursing pillow while pregnant, choose certified foam and let it air out fully. There's no need to replace an existing mattress you're happy with.

Indirectly, through the same additive story. Some flame retardants found in older furniture foam have been associated in studies with hormone disruption, and house-dust levels track with what's in the sofa and mattress. The evidence for fertility effects at everyday household levels is suggestive rather than settled. Dust control — vacuuming, damp dusting, washing hands before eating — reduces the main intake route for everyone in the house.

Babies are the group foam matters most for: they sleep up to 16 hours a day face-down on crib mattresses, mouth padded items, and crawl through the dust where foam additives end up. Several studies have measured higher flame-retardant levels in young children than adults, with hand-to-mouth dust contact as the likely route. This is why crib mattresses and nursing pillows are the best places to spend your certification attention — and why airing new baby foam items out properly is worth the few days' wait.

There's no strong evidence that foam poses a distinct risk to older adults. The general indoor-air and dust advice applies, and matters somewhat more for anyone with asthma or other respiratory conditions. Very old foam furniture — pre-2015 in the US especially — is more likely to contain the older flame-retardant chemistry, which is a reason to prioritise it at natural replacement time, not a reason to panic.

The well-documented part is the flame-retardant story: for decades, furniture foam (driven largely by a California flammability standard) carried added flame retardants, several of which were later restricted after being linked to thyroid and developmental effects and found widely in house dust and people. The standard changed in 2013–2014, and foam made since typically needs far less or none. Evidence on the foam polymer itself and on short-term new-foam VOCs points to a modest, mostly temporary issue.

Honestly: modest for most households, and lower than it was a decade ago. A cured, covered, certified foam mattress is a low-concern item. The risk concentrates in older upholstered furniture made in the heavy flame-retardant era, crumbling exposed foam, and sleeping on brand-new uncured foam without airing it. This is a "choose better at replacement time" material, not a "remove it from your home" material.

Within foam: CertiPUR-US certified foam restricts specific flame retardants, heavy metals, formaldehyde, and high VOC emissions — a meaningful floor, though not a promise of zero additives. GREENGUARD Gold covers emissions for cribs and mattresses. Beyond foam: natural latex, wool, and cotton-filled mattresses and pillows avoid the additive question largely, at a higher price. For sofas, some makers now sell flame-retardant-free upholstery and say so on the tag — worth asking when you buy.

Hard to avoid entirely — foam is in nearly every soft furnishing — but you don't need to. The practical version is easy: you replace mattresses and sofas only every several years, and at that moment certified or alternative options are widely available at similar prices. Between purchases, dust control and intact covers do most of the work. We rate this medium avoidability: big items, slow turnover, but clear better choices when the moment comes.

If you have a new foam item arriving — mattress, topper, nursing pillow — unwrap it straight away and let it air in a ventilated room for a few days before regular use. Off-gassing is front-loaded, so this single habit captures the most avoidable part of foam exposure at zero cost.

Keep the mattress you have. Focus on three moments: airing new foam before use, choosing certified foam (CertiPUR-US, GREENGUARD) when you genuinely need to replace something — crib mattresses and nursing pillows first — and retiring furniture with crumbling, exposed foam. Add regular vacuuming and you've covered the realistic exposure routes without spending anything extra.

NIEHS and CPSC publish accessible material on flame retardants in furniture. The CertiPUR-US and GREENGUARD programmes explain exactly what their certifications do and don't cover. For dust and indoor-air basics, EPA's indoor air quality pages are a solid starting point. See References below.