Polyurethane foam is the most common filling material used to make mattresses (for adults and crib mattresses) and is often found in couches, armchairs, and other types of furniture.
You can view the EPA’s latest position on the potential health impacts of polyurethane foam, here.
Polyurethane foam is made from fossil fuels
Polyurethane foam is made from fossil fuels and requires a lot of energy to make. It is also highly flammable, meaning it has to be doused with flame retardants in order to pass fires safety regulations. This kind of foam releases toxic chemicals when it burns, which can have a significant impact on health.
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).
The upshot is that polyurethane foam is bad news for you and bad news for the environment.
The hazards of polyurethane foam
Like TDI, methyloxirane is recognized as a carcinogen by the State of California and the U.S. Centers for Disease Control.
Methyloxirane and TDI are also listed on the List of Toxic Substances under the Canadian Environmental Protection Act. Animal research has found that propylene oxide is a direct-acting carcinogen.The US Environmental Protection Agency (EPA) has also highlighted several issues with the chemicals used in polyurethane manufacture.
For instance, the manufacturing plants that produce polyurethane foam are a major source of myriad hazardous air pollutants including:
- Methylene chloride
- Toluene diisocyanate (TDI) itself
- Hydrogen cyanide
So, even if the end product (the foam mattress in this case) doesn’t itself pose a health risk, its production does have an impact on those making the product, those living near factories where the product is made, and anyone else exposed to these chemicals through air and water pollution.
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. 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.
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 also poses a risk of exposure to the neurotoxin toluene, and dust from polyurethane may contain organotins, high concentrations of which are associated with growth abnormalities in mussels and oysters and mass mortalities of marine mammals. Dibutylin (a catalyst used in the manufacture of polyurethane foam) is a source of organotins, and has been found to cross the placenta in mammals and to accumulate in the brain, where it acts as a potent neurotoxin, killing brain cells. Organotins in general have been linked to disruption of behavioral functions, 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, which it does, and quite quickly. This, in spite of the industry claiming that polyurethane is durable.
So, polyurethane foam is produced from a non-renewable resource (oil), requires the involvement of numerous problematic chemicals, off-gasses those chemicals when it breaks down, and breaks down so quickly that you’re unlikely to be able to use a foam mattress comfortably for more than a couple of years.
Polyfoam mattresses are also quite porous and 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 this, many polyurethane mattresses come with a PVC cover to make them waterproof. And, of course, polyvinylchloride (PVC) comes with its own environmental and health effects.
Is there a better option, then? What are so-called eco-friendly foam mattresses?
Greenwashing and CertiPur foam mattresses
Look at most round-ups of eco-friendly, non-toxic mattresses and you’ll see a plethora of products made with CertiPur certified foam. This is a prime example of greenwashing.
CertiPur is a certification dreamt up by manufacturers with a vested interest in trying to make polyurethane foam sound eco-friendly and safe, when it’s anything but. If you’re looking for a truly safe and eco-friendly mattress, avoiding polyurethane foam is the way to go, whether it has a nice green stamp on it or not.
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. While better than much of the polyurethane foam out there, CertiPur foam is still resource-hungry, synthetic, and emits VOCs, so is best avoided.
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 or Ecolabel, 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.
One final point on foam mattresses: if you are buying a foam mattress, check where the manufacturer sources their foam and the density of the foam. If the foam is made in the U.S. or EU it is subject to stricter safety regulations than foam made in many other regions and countries. Foam can range from around 2.5 lbs. to more than 5.5 lbs. per cubic foot. Foam under around 3 lbs. is considered low density and typically feels soft. This kind of foam is usually too soft for a crib mattress, but you don’t want to go too dense as higher-density foams contain more polymers and, thus, require more resources to make and have more chemicals to off-gas.
You can check out our recommendations for better mattress materials here. For more information on all the other important things to consider when choosing a crib and mattress, check out the mattress section of this site.