Polyurethane foam is the most common filling material in mattresses and is also found in most couches, padded chairs, car seats, and elsewhere in the home. Despite its ubiquity, there are tons of problems with polyurethane foam.
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Polyurethane foam is made from fossil fuels
Polyurethane foam is made from fossil fuels using a lot of energy (which also comes from fossil fuels). This isn’t one of those cases where all that initial energy and resource use results in a long-lasting product and a lower lifetime environmental impact.
Quite the opposite, in fact.
Polyfoam isn’t very durable and begins to breaks down within just a few months, losing a significant amount of its mass in just a few years. This is why we don’t recommend Casper, Helix, or other popular foam mattresses to our readers; they are fundamentally fossil fuel derived products that are not built to last.
Polyfoam mattresses get lumpy and uncomfortable far faster than latex or latex hybrid mattresses. You’ll need to replace a polyfoam mattress much more often, which is bad for resource use and for your pocketbook.
As a petroleum product, polyfoam is also highly flammable. Some firefighters refer to polyfoam as ‘solid gasoline’.
This means manufacturers need to douse polyfoam in chemical flame retardants to pass fires safety regulations.
And when polyfoam does burn, it releases toxic chemicals that can have a significant impact on health. This is also true when polyfoam mattresses are incinerated at end of life, given that they’re practically impossible to recycle.
Foam density and resource use
If you are buying a foam mattress, check where the manufacturer sources their foam and the density of the foam.
Foam made in the U.S. or EU is subject to stricter safety regulations than foam made in many other regions and countries. Foam can range in density from around 2.5 lb. to more than 5.5 lb. per cubic foot. Any foam under around 3 lb. is considered low density and typically feels soft.
Foam that has a density of 3 lb. or less is usually too soft for a crib mattress. On the flip side, you don’t want to choose foam that is too dense as higher-density foams contain more polymers. More polymers means more resource use and more chemicals to off-gas.
The health hazards of polyurethane foam
Two of the key chemicals used to make polyurethane foam are toluene diisocyanate (TDI) and methylene diphenyl diisocyanate. These are mixed with water and polyols and catalysts such as dibutylin (DBT) are used to trigger a chemical reaction to create the foam. Polyols are substances created through a chemical reaction using propylene oxide (methyloxirane).
TDI and methyloxirane are recognized carcinogens and these aren’t the only chemicals of concern in polyfoam. In fact, the US Environmental Protection Agency (EPA) has highlighted several issues with the chemicals used in polyurethane manufacture.
Manufacturing plants that produce polyurethane foam are a major source of hazardous air pollutants. That means that even if a polyfoam mattress seems relatively safe to the end user, it was made in a way that puts the health and safety of workers, nearby communities, and the wider environment at risk.
In one case, the State of North Carolina forced the closure of a polyurethane manufacturing plant because tests revealed that local residents were being exposed to potentially dangerous levels of TDI.
CDC position on polyfoam
According to the CDC, occupational and significant environmental exposure can result in isocyanate-induced asthma, respiratory disease, and death. While safety has improved greatly in U.S. factories in recent years, there remains the potential for health problems related to accidental exposure to high levels of TDI as well as to cumulative exposure.
Largely due to a lack of data, the United States Occupational Safety and Health Administration (OSHA) has not established exposure limits on carcinogenicity for polyurethane foam from end-use products. This does not mean that it’s safe to sleep on a foam mattress, however, it just highlights the difficulties in attributing specific health conditions to chronic exposure to chemicals found in mattresses.
For obvious reasons, no scientists are going to conduct a controlled trial that may put humans at risk. Instead, we largely have to go on evidence from laboratory studies demonstrating the effects of short-term exposure to chemicals such as benzene, propylene oxide, and other chemicals in foam.
Polyurethane is bad news for waterways, aquatic life, and mammals
Polyurethane foam commonly contains the neurotoxin toluene and the catalyst dibutylin. These can off-gas or end up in dust from polyurethane foam. Dibutylin is a source of organotins, high concentrations of which are associated with growth abnormalities in mussels and oysters and mass mortalities of marine mammals.
Organotins can cross the placenta in mammals and can accumulate in the brain, where they act as a potent neurotoxin, killing brain cells. Organotins have also been linked to adverse effects on neurotransmitters and neuroendocrine pathways.
Polyurethane foam can also contain chemicals including styrene, antimony, formaldehyde, and others, all of which could end up in the dust produced when the foam breaks down.
Polyfoam and moisture
Polyfoam mattresses are porous, but not very breathable. This means they can accumulate moisture quickly, especially in humid environments. As such, these mattresses tend to harbor mold and mildew, which are health hazards in themselves.
To try to prevent mold and mildew, many polyurethane mattresses come with a waterproof PVC cover. Unfortunately, polyvinylchloride (PVC) has its own environmental and health effects. PVC is made with phthalates, for instance, which are known hormone disruptors.
Greenwashing and CertiPur foam mattresses
Most round-ups of so-called eco-friendly, non-toxic mattresses feature a plethora of products made with CertiPur certified foam. This is a prime example of greenwashing.
That said, CertiPur-US™ certification does offer some assurance that the foam component of a mattress is free from polybrominated diphenyl ethers (PBDEs) and some of the most egregious flame retardants, and that levels of formaldehyde and other chemicals including ozone depleting substances, mercury, lead, and other heavy metals, and hormone-disrupting phthalates are low. CertiPur foam is better than much of the polyurethane foam out there, but it is still resource-hungry, synthetic, and emits VOCs.
CertiPur standards are far less robust than the Ecolabel requirements used in the EU (for certain substances). Products certified by CertiPur are only tested for 72 hours, compared to 7 or 28 days for Ecolabel. Emission standards for VOCs, including formaldehyde, toluene, styrene, and other chemicals are also significantly less robust for CertiPur than for Ecolabel.
If your choice is between a CertiPur certified foam mattress and a foam mattress not certified by CertiPur, it probably is best to pick the CertiPur product. If you have the choice of a non-foam mattress, however, this is likely to be far healthier overall.
Final thoughts on the problems of polyfoam mattresses
Polyfoam is an environmental nightmare and health hazard in the home. Other major downsides to polyfoam include:
- Poor durability (which will cost you more long-term)
- Traps heat and moisture (terrible for hot sleepers)
- Very little edge support
- Poor postural support
- Hard to move around on the bed
- Poor responsiveness (bad for active sex!).