Memory foam is one of the most popular materials used in mattresses today. Mattresses that contain memory foam are well known for their exceptional pressure relief, motion isolation, and full-body hug. However, memory foam is also notorious for the chemical-like smell it emits when first unboxed.
No matter what kind of bed you sleep on, it’s important to know what materials your mattress contains and whether or not it’s toxic to your health. We’ll take an in-depth look at memory foam, exploring how it’s made and what chemicals may be present, to help you determine if a memory foam mattress is right for you.
What Is Memory Foam?
Memory foam is a type of polyurethane foam that has additives to make it viscoelastic. The increased elasticity and viscosity give this type of foam its most popular characteristic: the ability to contour closely to your body, leaving an impression behind when you get out of bed. Many sleepers enjoy the pressure relief memory foam provides, as well as its ability to cushion joints while aligning the spine.
While the material varies from manufacturer to manufacturer, memory foam used in most mattresses contains the following components:
- Polyols: A polyol is an organic compound that has multiple alcohol chemical groups, called hydroxyl groups. Polyol molecules are the foundation for polyurethane foam, though they also exist in food, fibers, and many other products.
- Diisocyanates: Like polyols, diisocyanates are also organic compounds. They’re combined with polyols to create a chemical reaction that results in polyurethane.
- Blowing Agents: After polyols and diisocyanates chemically react to form polyurethane, a blowing agent expands the substance’s cellular structure into foam. While manufacturers of memory foam traditionally used ozone-depleting chlorofluorocarbons (CFCs) as a blowing agent, most memory foam produced for mattresses today uses eco-friendly and nontoxic blowing agents, such as water.
To summarize, memory foam is made by mixing polyols and diisocyanates, then pouring the mixture into a mold, where it bubbles from the chemical reaction. A blowing agent is then added to expand the substance into foam.
What Makes Memory Foam Potentially Toxic?
The memory foam manufacturing process involves numerous substances that can be toxic to your health. Diisocyanates, the chemical reactants needed to make polyurethane foam, can cause respiratory irritation. Toluene diisocyanate (TDI), a known carcinogen, is a common reactant used to make memory foam that can cause skin and breathing problems. Additionally, certain blowing agents, such as CFCs, can be harmful to inhale and are damaging to the environment.
However, most chemicals used in mattress production, including TDI, are only harmful when vapor is released during the manufacturing process. Afterward, there may be trace amounts, but the vast majority of the fumes dissipate by the time you receive your mattress.
In recent years, the Federal Trade Commission established criteria for the labeling of mattresses as nontoxic and environmentally friendly. The regulations state that companies must have reliable scientific evidence backing a claim that a product is nontoxic for either humans or the environment.
The Environmental Protection Agency also banned the use of several blowing agents that were found to deplete the ozone layer. While many mattress manufacturers never used these particular chemicals, the regulations prompted companies that did to find less harmful alternatives. Manufacturers now use water-based or other types of approved blowing agents to help create memory foam’s distinct form.
Potentially Toxic Materials
The following chemicals may be present in memory foam mattresses:
- Methylbenzene: Also called toluene, mattress manufacturers use this solvent during the chemical reaction that creates polyurethane. It can cause neurological damage, skin irritation, and breathing problems if inhaled quickly or in large amounts.
- Formaldehyde: Formaldehyde can cause breathing issues and throat, eye, and nose irritation. In mattresses, formaldehyde works as an adhesive, though you’re unlikely to encounter it in mattresses made in recent years.
- Methylenedianiline: Commonly abbreviated as MDA, methylenedianiline is a reactant that’s mixed with polyols to make polyurethane. It can be a potential carcinogen for those who inhale or ingest it in large amounts.
- Methylene Chloride: This solvent is used widely and has many applications in manufacturing. Mattress companies use methylene chloride as a blowing agent and adhesive. It’s a potential carcinogen, and those who breathe in significant amounts can become dizzy or nauseous.
While this list may seem scary or overwhelming, it’s important to remember that many of these chemicals are only present in harmful amounts during the manufacturing process. Additionally, some are no longer used in mattress manufacturing due to regulations or restrictions. Many companies have also started incorporating green and organic mattress materials.
Flame Retardants
The Consumer Product Safety Commission requires that all mattresses sold in the U.S. include flame retardants or a fireproof barrier. Mattress manufacturers can use a number of different products to make their mattresses flame resistant. Some materials provide protection from fire naturally, while others contain chemicals.
Polybrominated diphenyl ethers (PBDEs) were commonly used as a retardant in the past, despite having harmful effects on both humans and the environment. However, PBDE compounds used in foam were phased out of use in 2004, so any memory foam products made after 2005 are unlikely to contain PBDEs.
Boric acid, a common household cleaner, also works as a flame retardant. It’s not a known human carcinogen, though it can cause skin and respiratory irritation as well as infertility.
Another compound commonly found in flame retardants is melamine, which is also used in some laundry detergents and construction materials. There is insufficient evidence that melamine causes cancer in humans.
While the CPSC monitors and regulates flame retardant chemicals, those wishing to avoid them altogether can choose a mattress that uses nontoxic alternatives. For example, many natural or organic mattress manufacturers use layers of wool as a fireproof barrier.
You can also opt for a mattress that uses silica-treated rayon or Kevlar, which are nontoxic and act as natural fire retardants.
Shop the Best Memory Foam Mattresses
What Is Off-Gassing?
If you’ve ever unrolled foam from a compressed package, you’ve probably noticed a chemical-like odor coming from the foam. This smell is due to the off-gassing of volatile organic compounds (VOCs) from the foam.
Any product that contains polyurethane foam will have some degree of off-gassing, though cheaper memory foam mattresses may retain and emit more fumes than mattresses made from high-quality foams.
While off-gassing can cause unpleasant odors, it’s completely normal and shouldn’t affect most people. Those who are particularly sensitive to smell or have respiratory issues should open foam products in a well-ventilated area and wait at least a day before use.
While VOCs in mattresses aren’t regulated by the EPA, several third-party organizations certify that products contain low amounts of VOCs and are free of certain harmful substances. Look for certifications from CertiPUR-US, GREENGUARD Gold, or OEKO-TEX Standard 100 while shopping for memory foam mattresses.
Is Memory Foam Safe?
Most people can enjoy memory foam’s benefits without any discomfort or side effects. Though harmful chemicals are present during the manufacturing process, they are mostly released by the time your new memory foam mattress reaches your home.
Trace chemicals left in the foam dissipate during the off-gassing process, which consumers can mitigate by ensuring they unroll foam products in a well-ventilated room. Those concerned about toxic components in memory foam can also purchase mattresses that carry third-party certifications.
Memory foam is generally considered safe for sleepers, though people with respiratory issues or certain allergies may find that the material irritates their skin or lungs. These sleepers can opt for natural latex or other organic mattresses that provide some of the same benefits as memory foam.
About The Author
Certified Sleep Science Coach, Director of Product Testing
David is a Certified Sleep Science Coach with a lifelong passion for well-being and health optimization. His interest in sleep developed with the arrival of his son, when sleep suddenly became a precious commodity.
- POSITION: Side Sleeper
- TEMPERATURE: Hot Sleeper
- CHRONOTYPE: Lion
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