The Complete Guide to Toxic Chemicals in Mattresses

In times gone by, mattresses were stuffed with feathers, horsehair, wool, and cotton batting, as well as other natural materials. With the introduction of synthetics, everything changed, and not exactly for the better. Now, most mattresses are made with a mix of polyurethane foam, synthetic latex, and conventional cotton, all of which present their own special kind of trouble.

If you’re interested in brands committed to combatting climate change and who avoid the use of questionable materials in their mattresses, see our list of the best non-toxic mattresses.

One industry leader, Walter Bader, was so concerned by the toxic slew of chemicals used in mattress manufacture that he sent several mattresses to an Atlanta-based lab for testing. One memory foam model was found to emit 61 volatile organic compounds (VOCs), including known carcinogens benzene and naphthalene!

Note: if you want to know what is in your mattress, you can actually send foam samples to Duke University for a toxicity analysis through their Foam Project.

In his book, Sleep Safe in a Toxic World, Bader compares the lack of regulations around mattresses to that of cigarettes in the 1930s:

‘Completely unregulated and everyone thinks they’re safe.”

Sleep Safe in a Toxic World

Bader went on to found Organic Mattresses Inc. (OMI), a company making handcrafted mattresses from cruelty-free wool, certified organic cotton, and 100 percent natural rubber latex in a facility where no one is allowed to smoke, wear fragrances, or even use fabric softeners.

Unfortunately, OMI mattresses are too pricey for many of us, but they are not the only company making mattresses with certified eco-friendly natural materials (although they’re arguably the best). Look around a little and you’ll find many mattresses made with 100 percent natural latex, organic cotton, organic wool, silk, bamboo, hemp, and other materials.

Nontoxic mattress brands

If you’re not sure where to start when buying a new mattress, it helps to know what to watch out for and what not to avoid (namely steel coils). If you’re already keen to buy a totally natural and non-toxic mattress, you can jump right ahead to our roundup of companies. Some of our most popular reviews are linked to below.

• Plushbeds (our top pick)
• Savvy Rest
• Avocado Green Mattress
• Obasan

If, however, you’re eyeing up a mattress and want to know just how bad polyurethane foam really is, or how much you should care about chemical flame retardants, you’re in the right place. 

Polyurethane foam

Also known as “Polyfoam”, polyurethane foam has been the standard fill for many mattresses since the 1960s. It is mass-produced and cheap, and the North America polyurethane market is dominated by four chemical giants: BASF, Bayer Material Science, The Dow Chemical Company and Huntsman Corporation, who account for more than 75 percent of total production. Personally, I’d rather not give these huge corporations my money, especially given their track records for transparency around the safety of their products and processes.

The market for polyurethane foam mattresses has, unfortunately, expanded even more in recent years thanks to the direct-to-consumer bed-in-a-box phenomenon. Sure, these mattresses are cheaper to produce and ship and reduce energy expenditure associated with transportation, but at what cost to the environment and your health overall? (Happily, there are eco-friendly bed-in-a-box options such as Avocado!)

Tariffs on polyurethanes

Interestingly, current politics may affect the seemingly exponential growth of this industry. That’s because in June 2018, the U.S. announced a 25 percent tariff on polyurethanes, PVC and lubricating oils. While it’s unlikely environmental considerations played a role in this decision, it may help in some small way to nudge companies to use more sustainable and eco-friendly materials available in the U.S. itself.

Why we are concerned about polyurethane mattresses

Why am I so against polyurethane mattresses? For a number of reasons. First, polyurethane foam is produced through the same energy-hungry process used to make petroleum from crude oil. This process involves two main ingredients: polyols and diisocyanates, which are reacted together using a variety of catalysts, including dibutylin (DBT, more on this below). 

Polyols themselves are substances created through a chemical reaction using propylene oxide (methyloxirane). As for diisocyanates, toluene diisocyanate (TDI) is the most common isocyanate involved in the manufacture of polyurethane.

Both methyloxirane and TDI are recognized as carcinogens by the State of California and the U.S. Centers for Disease Control. They’re known to cause tumors (mostly mammary and brain tumors for methyloxirane and TDI respectively) and are both listed on the List of Toxic Substances under the Canadian Environmental Protection Act. “Studies in animals have demonstrated that propylene oxide is a direct-acting carcinogen” (R).

You know things are bad when even the somewhat beleaguered US Environmental Protection Agency (EPA) – whose inspections have fallen to an all-time low under the Trump presidency – has issues with the chemicals used in polyurethane manufacture. Indeed, the EPA considers the manufacturing plants producing polyurethane foam to be major sources of myriad hazardous air pollutants. Such pollutants include:

• Methylene chloride
• Toluene diisocyanate (TDI) itself
• Hydrogen cyanide

Part of being a conscious consumer is understanding the impact of our choices on those producing the things we buy. This is driven home by the numerous cases of occupational exposure in factories to the chemicals just mentioned. According to the CDC, such 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.

Worker safety and TDI plants

We also need to consider the wellbeing of those living close to manufacturing plants, who often have limited income and little opportunity to move away. Again, this is highlighted by a case where 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.

How about in our own homes, though? Unfortunately, the United States Occupational Safety and Health Administration (OSHA) has not established exposure limits on carcinogenicity for polyurethane foam from end-use products. This is largely due to a lack of data and does not mean that we’re not exposed to hazardous air pollutants when we sleep on a polyurethane mattress, sit on a couch made with the stuff, or breathe in dust from carpet underlay and other polyurethane products.

As with all chemicals, it’s the dose that makes the poison. And, unfortunately, it’s very difficult to quantify cumulative exposure to VOCs and other chemicals from all of the products we come into contact with each day. Testing just one product and finding low VOC emissions does not, therefore, offer much assurance of safety if this is just one of the sources in a household, daycare, school, or work environment. Attributing specific health conditions to chronic exposure to chemicals found in mattresses is also difficult as it would be impossible to design a study controlling for ever variable throughout a person’s life. 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 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’ll have a lumpy and uncomfortable mattress to get rid of every few years. Any other issues? Yes!

Polyfoam mattresses and mold

Polyfoam mattresses are also quite porous, meaning that they can accumulate moisture and tend to harbor mold and mildew. And, as polyurethane is highly flammable (it’s basically solid gasoline), safety regulations mean that mattresses are drenched in toxic flame retardants in order to make them ‘safe’.

It’s plain to see, then, that the smart move is to avoid polyurethane foam in our mattresses and in our homes as a whole.

Are there any good things to be said about polyurethane foam? Perhaps. At a stretch, you might say that polyurethane is recyclable, with manufacturing scraps often reused to create carpet backing. However, end user products, such as mattresses, are very difficult to recycle and mostly end up in landfill where they break down and release toxins into the ground, air, and water. 

Some other things to consider about foam mattresses include, and I’m not joking, the potential effects on your sex life, and the kind of climate where you live. Foam mattresses don’t wick away moisture or do much for breathability, so you’re liable to sweat a lot unless you use a mattress topper made with organic wool or cotton. The support many enjoy from a foam mattress, can also have unintended consequences if you rely on a little ‘bounce’ in the bedroom. Consider yourself warned!

Fun Fact: If you lived in Canada and bought a polyurethane foam mattress or other foam product between 1999 and 2012, you may have been overcharged! Foam manufacturers were recently found to have formed a price-fixing cartel and consumers were given the opportunity to file claims for compensation. If you didn’t file a claim, you’ve missed out, sadly, but you can still read all about Canada’s biggest ever price-fixing scandal here!

What about CertiPur foam mattresses?

Foam mattresses continue to be popular as they can (initially) offer good support regardless of your body size and shape. Unfortunately, even the most expensive foam mattresses are made with polyurethane which, as we’ve seen, breaks down quickly, is sweaty, and is bad for factory workers, the environment, and for the end user (i.e. you and your family).

Many eco-friendly mattress round-ups feature mattresses made with CertiPur certified foam. CertiPur is a certification dreamt up by manufacturers with a vested interest in trying to greenwash polyurethane foam. Sure, some foam products are less problematic than others, but if you’re looking for a truly safe and eco-friendly mattress, avoiding foam is not a decision you need to sleep on. See our top certifications for mattresses here.

The CertiPur-US™ logo does offer some assurance that the foam component of the pillow is free from some polybrominated diphenyl ethers (PDBEs) 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. However, foam is still resource-hungry, synthetic, and emits VOCs, so it is best avoided. 

Indeed, CertiPur standards are much lower 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 more robust for Ecolabel compared to CertiPur.

If the difference in emissions levels doesn’t phase you much, consider this: research shows that VOC emissions from polyurethane foam mattresses are higher than those of polyester foam and that even minimal VOC emissions in pregnancy and in the postnatal period can be harmful for infants’ neurological development, growth, immune and respiratory function (including an increased risk of asthma and allergy), and overall health and well-being. Now consider that you may spend some time co-sleeping with your infant in your own bed.

Research has also found that certain ‘nesting’ behaviors in the late stage of pregnancy can increase the level of VOCs in the house and, in turn, increase the risk of respiratory wheezing in infants and the development of atopic dermatitis by more than three times. So, if you’re thinking of installing new carpet, painting the nursery, or buying new furniture while pregnant, you’ll want to, as much as possible, choose products that don’t off-gas VOCs. That includes choosing a non-toxic, eco-friendly crib mattress.

Top tip – Watch out for companies marketing their foam mattresses as ‘plant-based’. These often contain just a tiny amount of plant-derived oils alongside polyurethane foam, making no great difference to the product’s eco-friendliness.

Flame retardants and other VOCs in mattresses

Have you ever wondered what that weird smell is when you unroll or uncover a new mattress? Most likely, that is the lovely aroma of volatile organic compounds (VOCs), including a heady mix of flame retardants and other chemicals.

VOCs, many of which are classed as carcinogens, are emitted as a breathable gas from mattresses, carpets, furnishings, paint, cleaning supplies, printer ink, and other household products. Concentrations inside the house can be ten-fold higher than outdoors and, consider this, you spend a good 7-9 hours a night with your face smushed into your mattress. If you’re an infant, you may spend more than 12 hours a day in close contact to a source of VOCs, with studies showing increased concentrations of VOCs in incubators due to mattresses off-gassing, especially when the air is hot and humid.

Even though manufacturers claim that the polyols and isocyanates in mattress foam have reacted and are no longer volatile, older polyurethane foam mattresses are especially bad for off-gassing as the mattress breaks down into dust. VOCs in mattresses also include a variety of chemicals used as stain and soil repellents, antimicrobial treatments (which are necessary for porous polyurethane foam), adhesives, and flame retardants. 

VOCs and health issues

VOCs can cause headaches, nausea and dizziness, nasal irritation, allergic reactions, neurological problems, liver and kidney damage, cancer, and possible even fertility problems and miscarriage. As if that wasn’t bad enough, some VOC’s are greenhouse gases, meaning that they contribute to climate change (which has its own negative effects on health, such as increasing air pollution from wildfires/climate fires and causing soil erosion, flooding, increasingly deadly tornadoes and more). 

The California law that made flame retardants mandatory nationwide

Ironically, the state that now seems intent on leading the way in terms of eco-friendly regulations is the one we can blame for the presence of toxic flame retardants in mattresses. Back in 1975, the State of California passed legislation (TB117) requiring manufacturers to treat mattresses and furniture to make them safe from cigarettes that could smolder and start a fire. This legislation did not, however, offer guidance as to how to make these products safe, meaning that manufacturers began dousing everything in Polybrominated Diphenyl Ethers (PDBEs). So as not to have to create two sets of mattresses for sale nationwide, mattress manufactures chose to use the California’s standard in all their mattresses.

Researchers found PDBEs in the majority of dust samples collected from homes in California in 2015, even though the state updated TB117 in 2014 to enable manufacturers to transition from the open flame test process adopted and mandated in 1975 to the new methods for smolder resistance. This revision does not explicitly call for the elimination of flame retardants such as PDBEs, however, and many manufacturers continue to use these dangerous chemicals in their products.

PBDE levels higher in North America

Unsurprisingly, then, levels of PBDE in North America are reported to be higher than those in Europe and Asia, and the body burden of PBDEs is three- to nine-fold higher in infants and toddlers than in adults (R). This is likely because of exposure to maternal milk and dust.

The most common PBDE isomers found in humans are Tetra-, Penta-, and Hexa-BDEs. PBDEs have a long half-life, meaning that they persist in the environment. Studies suggest that these chemicals may cause (R, R):

• Disruption to thyroid function
• Neurodevelopmental deficits and long-lasting behavioral and motor activity anomalies 
• An increased risk of cancer

Antimony, Boric Acid, and Halogenated Flame Retardants (HFRs) are some other commonly used chemicals found in mattresses.  Antimony is a toxic heavy metal which can cause eye, heart, and lung problems. Boric Acid can cause eye and respiratory irritation. 

Bromine, chlorine, fluorine and iodine are elements known as halogens. Halogenated flame retardants act directly on flames, interfering with the chemistry of the flame to prevent fire. Chlorine (chlorinated) and bromine (brominated) are both used as flame retardants, but brominated retardants are the most effective. 

HFRs have been linked to a raft of health concerns, including (R): 

• Abnormal reproductive development and delayed puberty
• Neurobehavioral changes, damage to brain and nerve function
• Thyroid disruption
• Cancer

European regulations

In Europe, pan-European Union legislation such as REACH and RoHS, as well as the Stockholm Convention (to which the USA is not a signatory) effectively mean that the use of brominated fire retardants is being phased out for good. In the U.S., however, bans on the use of HFRs vary from state to state.

As noted, flame retardants are found at increasing levels in household dust. And, because many halogenated flame retardants are persistent and bioaccumalative, they are increasingly present in human blood and breast milk, and in wild animals, with widespread environmental contamination and the highest concentrations in the Arctic and marine mammals (R). Natural materials such as hemp, wool, and flax offer alternatives to chemical flame retardants.

In one article, Arlene Blum, a biophysical chemist and visiting scholar at the University of California, Berkeley, suggested that, “Instead of adding new fire retardant chemicals that ultimately may be shown to cause health problems, we should be asking whether we need to use these chemicals or if there are other ways to achieve equivalent fire safety, so many of the chemicals we have banned in the past were flame retardants—think about asbestos, polychlorinated biphenyls, polybrominated biphenyls, tris(2,3-dibromopropyl) phosphate, PBDEs—[and] they all ended up in the environment and in people. We need to think carefully about adding these sorts of chemicals to consumer products before there is adequate health information.”

Novel strategies for making mattresses fire-resistant

Some companies are investigating novel strategies to make mattresses fire-resistant, such as using nanomaterials to coat fibers. Unfortunately, there is limited safety data on nanoparticles (and what there is has caused some concern) and some of the chemicals used to disperse nanoparticles in treated fibers may themselves be toxic (R). Other researchers are investigating the use of tartaric acid derivatives as a natural flame retardant (R). This chemical looks promising as an eco-friendly treatment and is produced in large quantities in the normal course of making wine.

While some fire retardant chemicals have been banned, other potentially problematic chemicals continue to be used in children’s products, including Firemaster 550, a toxic phthalate-containing cocktail. Children’s mattresses and crib mattresses are also commonly treated to make them waterproof. It’s a tragic irony, then, that infants and children are also more vulnerable to the negative effects of the chemicals used in waterproof covers, such as the phthalates found in vinyl. Indeed, a law was passed in 2009 in the U.S. House of Congress forbidding the use of three types of phthalates often found in mattresses. 

If, despite all of this, you’re still in the market for a foam mattress that has, by necessity, been treated with chemical flame retardants and other toxins, there are some questions you’ll want to ask before making a final decision. 

Questions to ask about foam mattresses

First, check where a company sources their foam. If it is made in the U.S. or EU it is subject to stricter safety regulations than foam made in many other regions and countries.

Second, look at how dense the foam is. 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 can feel soft while still being comfortable. The other benefit of lower-density foam is that it contains lower amounts of polymers and, thus, uses fewer resources and has less to off-gas. 

Finally, you’ll want to check how the mattress meets safety requirements for flammability. If a product is coated in chemical fire retardants, avoid it and look for one that has an outer cover made with something like Rayon, silica and Kevlar (check that this doesn’t just apply to mattress seams). These materials are far from eco-friendly, but they can help reduce the amount of chemicals that need to be applied for a mattress to meet fire safety standards.

Is your mattress VOC free?

If a company claims that their mattresses are VOC-free, make sure this is not just marketing hype. Mattress companies have been fined over and over again for making false claims over VOCs. The Federal Trade Commission sued and fined Essentia, Relief-Mart/Temp-Flow, and Ecobaby Organics for claiming that their products were VOC-free without the evidence to back up such claims.

Tuft and Needle mattresses vs. Casper, Leesa and Purple

One of your best options is Tuft and Needle’s CertiPur mattress. This was the first complete mattress to be certified STANDARD 100 by OEKO-TEX® and is also GreenGuard Gold certified and CertiPUR-US® certified as emitting fewer than 0.5 parts per million VOCs. Casper, Leesa, and Purple all sell CertiPur foam mattresses, but none of these have OEKO-TEX® or GreenGuard Gold certification and Tuft and Needle’s mattresses are less expensive than the competition, ranging from $350 to $750 depending on mattress size. The company also offers a 10-year limited warranty and has a decent return/refund policy as well as a 100-night free trial.

Plushbeds mattresses

PlushBeds also offer a memory foam mattress collection, an Eco Bliss mattress collection (see our review here), a Gel Memory Foam Sofa Mattress, and RV Mattresses. These are all made with PlushBeds’ proprietary CertiPUR-US® certified PlushFoam™. The mattresses have low VOC emissions and are free from:

• Ozone-depleting chemicals
• PBDE flame retardant 
• Prohibited phthalates
• Mercury, heavy metal and lead
• Formaldehyde

There’s also the option of biofoam mattresses, although these are nowhere near as eco-friendly as manufacturers would like us to think.

Soy foam mattresses

Beware companies advertising their foam mattresses as ‘green’ and ‘plant-based’. Bio-based foam made with soybeans might seem like a great innovation, but the truth is that these mattresses are still almost 100 percent polyurethane foam. Yes, including some soy-based foam does reduce the greenhouse gas emissions associated with foam mattresses, but when you look at the actual math (not the numbers claimed in advertising), the reduction is very small.

For instance, if you see a mattress being advertised as made with 20 percent bio-based foam, you might, quite reasonably, expect a fifth of the total mattress to be plant-based. Unfortunately, that’s not the case. Instead, the 20 percent claim only applies to the polyol portion of the foam in the mattress, and, as we’ve seen, polyols and isocyanates are combined in almost equal amounts to make polyurethane foam. So, in a mattress with 20 percent soy-based foam, this actually translates to around 10 percent of the foam being bio-based. The other 90 percent is exactly the same as other polyurethane foam mattresses not claiming to be ‘green’.

Are soy bio-foams climate friendly?

How about the resource use question? Can soy-based bio-foams reduce energy input for a mattress? Again, the math isn’t as good as manufacturers want us to think. Soy-based polyols may use around 23 percent less energy to produce than traditional petroleum-based polyols, but if a product only uses 20 percent soy polyols, the energy saving amounts to less than 5 percent overall. It’s better than nothing, but it’s hardly something on which to base your whole marketing campaign.

Then there’s the consideration over the environmental toll of soy grown for anything other than human consumption. Most soy crops are grown to feed livestock and most (more than 90 percent) are genetically modified crops that increase farmers’ reliance on pesticides and herbicides. To grow more soy for the purposes of fattening up cattle and producing foam for furniture means that companies destroy yet more of the Amazon rainforest. This has a huge negative impact on biodiversity and local communities, and itself contributes to climate change, but none of this is included in energy cost calculations. 

Soy bio-foam might not be better for the environment

It is a mistake, then, to assume that soy-based biofoams are better for the environment than regular polyurethane. Instead, I would be wary of any company trying to use such claims to greenwash their products and overall company image. Polyurethane foam mattresses, whether they contain a modicum of soy or not, continue to negatively affect human health and the environment, and soy foam is not even readily biodegradable, so will end up in landfill with the rest of those toxic foam mattresses. 

Top Tip – Think of ‘biofoam’ as akin to someone trying to sell you ‘safe’ cigarettes made with 10 percent organic tobacco. 

For a truly eco-friendly mattress, check out the PlushBeds Botanical Bliss Organic Latex Mattress, which is handcrafted with GOLS certified organic latex latex, GOTS certified organic cotton, and GOTS certified organic wool. This mattress is also Oeko-Tex Standard 100 and GreenGuard Gold certified for purity.

Why choose GOLS latex? Well, to avoid the problems of synthetic latex for a start.

Synthetic latex

Natural latex is an excellent eco-friendly and safe material from which to make mattresses. Unfortunately, many latex mattresses are made with synthetic latex, which is, essentially, a petroleum product chock-full of toxic chemicals that off-gas VOCs. As such, you’ll want to check the nature of any latex in any mattress you’re considering purchasing.

How is synthetic latex made?

Synthetic latex is made using styrene and butadiene, two petroleum-based products and VOCs. It may also be called styrene-butadiene rubber (SBR). When SBR is mixed with 100 percent natural latex, some manufacturers disingenuously refer to the final product as natural latex. Natural latex may also be used to describe a combination of polyurethane and 100 percent natural latex.

Look, then, for products that specifically state that they are made with 100 percent natural latex, ideally with Global Organic Latex Standard (GOLS) certification.

Why would you want to avoid synthetic latex? 

• Styrene is toxic to the lungs, liver, and brain and may increase the risk of leukemia and lymphoma (R)
• Butadiene is harmful to the nervous system, may be carcinogenic, and irritates eyes and skin (R)
• Synthetic latex, as a petroleum product, is unsustainable and resource hungry
• Synthetic additives (many of which are themselves toxic) are used to make this latex stable
• Synthetic latex is not biodegradable, but is also not durable or recyclable
• Synthetic latex is not resistant to mold, mildew, or dust mites (100 percent natural latex is somewhat resistant)
• Synthetic latex is not fire-resistant, so must be treated with flame retardants (typically toxic chemicals)

Because 100 percent natural latex requires the cultivation of Hevea-Brasiliensis trees and the processing of the rubber tree sap, it is more time-consuming and currently costs more than creating petroleum-based synthetic latex which can be made quickly in a laboratory. Expect, then, to pay more for latex that is 100 percent natural, but know that the true cost is much lower when you factor in your health, your family’s health, worker health, and the wider environment. 

Mold, dust, and mildew

Mold, dust, and mildew are legitimate concerns when choosing a new mattress. Some materials are far more prone to these issues than others, and the health and cost consequences can be significant. 

Dust mites

Dust mites feed off the hair and skin we and our family members shed every day. The mites then defecate, and their feces accumulate inside mattresses, couches, and other soft furnishings. Rather than being allergic to dust itself, approximately 10 percent of people in the U.S. are thought to allergic to dust mite feces and fragments of dust mites (R). As an adult human can shed enough skin every day to feed a million dust mites and dust mites poop a lot (R), it’s not surprising that an old mattress can be especially bad news if you have a dust mite allergy.

Thankfully, dust mite covers work well to protect your mattress from dust mites as well as from bed bugs and other critters. Some mattress materials also have their own in-built protection against dust mites, such as 100 percent natural latex, which is unattractive to dust mites. Wool is also naturally resistant to mold and mildew, has natural flame-retardant and antimicrobial qualities, and is resistant to dust mites, making it a great option for allergy sufferers. 

Other types of bedding are like a teeming metropolis for dust mites, however, including down bedding, soft pillowtops, innerspring coil mattresses, and old foam mattresses, especially those that sleep hot. Mites gravitate towards warm, moist environments, meaning that the inside of a mattress is sheer bliss for dust mites. 

To keep dust mite allergens to a minimum in your bedroom, take the following steps:

• Cover mattresses, pillows, and duvets in zippered, dust-proof covers made with material woven so tightly that dust mites and their feces can’t get through. Look for ‘allergen-impermeable’ covers such as this cotton mattress cover certified by the Asthma and Allergy Foundation of America.
• Wash bedding once a week in hot water (130 F at least) to kill mites.
• Avoid wall-to-wall carpeting, curtains, down pillows and comforters, upholstered furniture, and other items in your bedroom that can harbor mites.
• Get a certified filter vacuum cleaner that can help keep mites and waste out of the air.

If you are prone to allergies, or are disinclined to use a mattress cover, it’s advisable to avoid innerspring mattresses as the inner cavities allow skin, hair, dust mites and their waste to accumulate. Condensation can also form on the metal coils in these mattresses, caused by body heat, and this can lead to mold and mildew developing, creating other potential allergens in your bedroom.

Mold and mildew

The most common reason mattresses develop mold is due to the accumulation of moisture from sweat. A breathable, but tightly woven waterproof bed cover, such as the allergen cover recommended above, can help minimize how much sweat makes it through to your mattress. A washable cover or mattress topper can also help prevent mold from taking hold in a mattress. 

There are other ways to minimize the risk of developing mold in a mattress: use a slatted bedframe and flip your mattress or air it out regularly. If a mattress sits for years on a solid board or box spring this means that moisture has no opportunity to evaporate. Also, never get into bed straight out of the shower or pool, be sure to dry your hair before bed, and keep damp towels and clothes off your mattress. 

Almost all mattresses are susceptible to mold, although some are worse than others. Mold spores are especially fond of finding homes in open cell foam mattresses and older foam mattresses that have begun to disintegrate. This is why mattress manufacturers often douse foam mattresses in toxic antifungal chemicals. Kapok, 100 percent natural latex, and wool are better options for mattress materials as they have at least some mold-resistant properties. 

Even if you take precautions after the mattress reaches you, a mattress that has sat around in a warehouse for a long period of time may already be infested with mold before it arrives at your door. Buying from a company that makes mattresses to order helps to minimize this risk.

Why does it matter? Well, children who sleep on mattresses that test positive for mold spores were shown in one study to be three times more likely to have asthma. In another paper, Mudarri and Fisk (2007) estimated that more than a fifth (21 percent) of cases of asthma in the U.S. could be attributable to dampness and mold in housing. 

Mold allergy has also been associated with symptoms such as headaches, fatigue, nausea, eye irritation, runny nose, and insomnia, although evidence supporting this association is limited.

Mold has proven such a problem with some foam mattresses that it has led to class action lawsuits, such as the one filed in California in 2008 against Sleep Country. Interestingly, the company making the mattresses, Select Comfort, claimed that mold cannot be considered a defect because it is present in many products and the air. A company spokesperson is also alleged to have said that, “The only difference with a Sleep Number bed is you have the ability to open it up and take a look at it. … You cannot do that with an innerspring bed or other upholstered product. It’s not a product defect, because mold can occur in any upholstered product.”

Happily, many 100 percent natural latex, wool, and cotton mattresses come in a layered construction that means they can be examined fairly closely for mold. And, in contrast to foam mattresses, complaints are few and far between for these natural materials. 

Vinyl

Some mattresses, especially crib mattresses, come with a waterproof and antibacterial cover. Typically, this is made with vinyl, a material made using toxic chemicals and additives associated with serious health concerns. As vinyl is exposed to heat, moisture, and air (as in normal mattress use), it breaks down and leaches out chemicals. 

Some of the chemicals in vinyl include phthalates and heavy metals like antimony. These can have adverse effects on reproductive health and development (R), may trigger asthma and allergies (R), and can have effects on childhood development and behavior (R).

Vinyl production also releases dioxins, which I’ve written about many times at Leaf Score as these chemicals can cause cancer, birth defects, and changes in neurological development.

All of these effects are very worrying, especially given that vinyl is most commonly found in crib and children’s mattresses. So, even if most of your chosen mattress is ‘natural’, the cover may be made of synthetic latex or vinyl, urethane, 4-phenylcylclohexene, or polyvinyl chloride (PVC). As manufacturers are not legally required to list vinyl on labels, be sure to ask if it is present when buying any new mattress.