The best natural materials for a crib mattress, plus the pros and cons of each textile.
There’s no shortage of troublesome chemicals and materials in most crib mattresses. Thankfully, though, there are some great options for more eco-friendly, non-toxic crib mattress materials. That means, with a little research, you can easily avoid polyurethane foam, polyester, polyvinyl chloride (PVC), and other perils.
Importantly, some of the best materials for a crib mattress differ from those I’d recommend for an adult mattress. While crib mattresses may seem overly firm by adult standards, a firm sleep surface is essential for sleep safety for infants. Too soft a surface and an infant may struggle to maintain a clear airway.
My top pick for an eco-friendly, non-toxic crib mattress is the Naturepedic Organic Cotton Classic Crib Mattress (View Price on Naturepedic). This waterproof mattress is made with:
- Organic cotton
- Innersprings
- Non-GMO sugar cane derived polyethylene waterproof cover.
It is made without harmful chemicals, and contains no latex, soy, GMOs, vinyl/PVC, phthalates, formaldehyde, flame retardants, polyurethane foam, or perfluorinated compounds (PFCs). You can read my full review here and check out The Best Eco-Friendly & Nontoxic Crib Mattresses.
The best materials for crib mattresses
The best materials for crib mattresses are those that:
- Don’t off-gas
- Have a lower carbon footprint (typically) than synthetics
- Are easily recycled or are fully biodegradable
- Create a firm sleep surface
- Help regulate temperature
- Are breathable.
Fitting these criteria, eco-friendly crib mattress materials include:
- Organic wool
- Organic cotton
- 100 percent natural latex (Dunlop, ideally, not Talalay, which is softer)
- Hemp
- Coconut coir (with caveats)
- Innersprings.
We’ll look at the pros and cons of each material in turn below.
Pros and Cons of Wool for Crib Mattresses
Wool offers a variety of benefits as a crib mattress material. Wool is:
- Moisture wicking
- Naturally flame resistant
- Naturally antimicrobial
- A great thermoregulator
- free of off-gassing!
- Firm
- Naturally water repellent
- Naturally resistant to mold and mildew
- Resistant to dust mites..
A wool mattress or mattress top can help your baby maintain a comfortable body temperature, keeping them cool in summer and warm and cozy in winter.
Wool is also fairly firm, making it a good fit for a crib mattress as it won’t compress and conform to a baby’s body and create a safety hazard as a softer mattress might. Wool is also naturally water-repellent, assuming it still holds some of its lanolin (an oily substance produced by sheep).
Downsides to wool
Unfortunately, some infants can develop an allergy to lanolin, although not usually to wool itself. And, as wool mattress covers are water repellent because of their lanolin content (some even have lanolin added), the risk for a lanolin allergy may be higher than with regular wool.
Many ‘wool’ allergies are actually a reaction to the chemicals used to process non-organic wool. Choose organic wool products and use a top sheet made with organic cotton to limit your baby’s direct contact with wool if you’re worried about allergies.
Bear in mind that while wool is water-repellent, it is not, however, water-resistant. This means that you’ll still want to buy a mattress with a waterproof cover made with food-grade polyethylene, or cover a crib mattress with a waterproof polyethylene cover and use an extra wool puddle pad for protection.
Other downsides of a totally wool crib mattress are the cost, heaviness, and greater resource use. Although it’s nowhere near as environmentally taxing as making a polyurethane foam mattress, wool production does have an impact on the environment and wool that isn’t organic may be produced with chemical pesticide and fertilizer inputs and other chemicals such as bleach.
Certifications to look for in a wool crib mattress
One other downside of wool is that it’s not vegan-friendly, although some sources of wool are considerably better in terms of animal welfare. In the US, wool marked with the PureGrow™ label comes from Californian farms that practice sustainable sheep ranching. EcoWool is similar, and both are arguably preferable to New Zealand wool in terms of animal welfare. Wool certified USDA Organic is also a decent option as is any wool product with GOTS certification.
To really up your eco game, look for organic wool that carries the European kbT certificate awarded to products made with wool sourced with minimal animal exploitation.
Pros and Cons of Organic Cotton Crib Mattresses
Conventional cotton is an environmental nightmare and potential source of exposure to toxic chemicals. As such, we would only recommend a crib mattress made with organic cotton.
Organic cotton:
- Is natural and non-toxic
- Creates a firm sleep surface
- Isn’t as flammable as petroleum-based foam
- Doesn’t off-gas toxic fumes (even if it does burn)
- Relatively inexpensive (compared to organic wool and latex)
- Grown in the U.S.!
Organic cotton is an excellent option for a crib mattress, with many eco-friendly crib mattresses available with an organic cotton cover over a layer of wool (as a fire barrier), and an innerspring and cotton batting or natural latex interior.
There are very few downsides to organic cotton for mattresses. Bear in mind, though, that mattresses comprising mostly cotton tend to be heavier and firmer than foam mattresses. That firmness is a plus, though, helping to support infant sleep safety!
Pros and Cons of 100 Percent Natural Latex
Latex (natural rubber) is a fantastic choice for eco-friendly, non-toxic crib mattresses. This material is:
- Renewable
- Durable
- Porous and breathable
- Cooling or thermoregulating
- Available in various levels of firmness
- Naturally antimicrobial
- Resistant to mildew and dust mites
- Easy to care for
- Recyclable
- Fully biodegradable at end of life.
Rubber trees can provide rubber serum for up to 30 years and the resulting latex is firm, bouncy, and durable. Although it isn’t as biodegradable as wool or cotton, natural latex can be recycled for use as underfloor insulation or other fill. And, eventually, it will biodegrade without releasing toxins into the environment, unlike polyurethane foam.
Latex crib mattresses typically use molded latex Dunlop foam, which is chemical-free and slightly firmer than most polyurethane foam and Talalay latex.
Downsides of latex for crib mattresses
Latex crib mattresses are a little more expensive than some other mattresses made with natural materials, with the cost usually dependent on certifications.
Relevant certifications for latex crib mattresses include:
- GOLS – the Global Organic Latex Standard
- FairRubber
- Rainforest Alliance Certified.
These certifications help offer assurance that the mattress is made using certified organic rubber sourced in a sustainable way by workers who are well treated and properly paid.
Latex mattresses can have a rubbery smell at first, so it’s best to air them out for a few days before sleeping on them. It wouldn’t hurt to pair this airing out with a nursery air filter. This is not a sign that the mattress is off-gassing toxic chemicals, it is simply the natural smell of rubber and will dissipate within a few days.
Some crib mattress manufacturers avoid using latex because of concerns over latex allergies in infants. This is an area where fearmongering appears to trump science, given that there’s no evidence of latex mattress use resulting in latex allergy in infants. Check out the FAQs below for more on latex allergy in infants.
Pros and Cons of Hemp Mattresses
Hemp is a wonderfully sustainable, renewable resource and can be a fantastic material for mattresses. However, I’m yet to track down a crib mattress made with hemp. If one does exist, chances are that it’s a good option for a firm mattress in a hot and humid climate such as a nursery.
Hemp is:
- Breathable
- Moisture-wicking
- Naturally antimicrobial and antibacterial
- Resistant to mold and mildew
- Odor-repelling
- Resistant to pests (as a crop)
- Fast-growing, requiring very little water and no pesticides
- Fully biodegradable.
Hemp is one of the most breathable materials available. It can help a baby stay cool even in hot and humid temperatures and helps wick moisture away from their skin. This means it’s good for keeping the mattress feeling fresh, especially as hemp is naturally anti-microbial and anti-bacterial.
Hemp is resistant to mold and mildew and doesn’t hold onto odors. That said, as with all crib mattresses, I’d be sure to cover any hemp mattress with a food-grade polyethylene waterproof cover and a puddle pad to help minimize the potential for soiling.
Hemp grows so thick and fast that it prevents weeds from growing nearby. This means that hemp cultivation typically doesn’t require the use of pesticides or herbicides, nor fertilizers as hemp actually enriches the quality of soil. And, because hemp roots grow deep, they are good at using groundwater and help reduce soil erosion.
Pros and Cons of Innerspring Crib Mattresses
An innerspring mattress is an excellent choice for a crib mattress. Innerspring mattresses can be:
- Lightweight
- Comfortable
- Breathable
- Cooling
- Durable
- Inexpensive
- Dual firmness (for infant through to toddlerhood).
The comfort and quality of these mattresses largely depends on how many layers the mattress has and what goes into the layers, as well as the type of cover on the mattress. For instance, a high-quality mattress may have a central layer featuring steel coils wrapped individually in PLA (a corn-based bioplastic) and/or cotton, with a layer of latex or cotton batting, wrapped in a layer of wool, with another layer of cotton, and, finally, a waterproof cover made of polyethylene.
Some innerspring mattresses have a layer of foam instead of cotton or latex. Check the construction of each layer of a mattress before buying.
Innerspring crib mattresses that have dual firmness typically have a softer latex layer or foam layer for the ‘toddler’ side of the mattress and a wool or cotton batting layer for a firmer sleep surface for an infant. This isn’t strictly necessary, though, given that most toddlers will quite happily sleep on a firm mattress. Also, you can simply add a comfort layer on top of the mattress, such as a thin layer of Talalay latex after the age of one, should you wish.
Good innerspring crib mattress design
While dual firmness isn’t essential, border rods are. In an innerspring crib mattress, border rods provide strong side and edge support so that the mattress doesn’t sag or compress unduly when a baby stands or walks on the mattress edge.
The number of steel coils or springs in a mattress can affect the quality of a mattress but they don’t always indicate how firm the mattress will be. Instead, a high-gauge is the best indicator of the spring unit in a mattress.
The insulator pad is also important in an innerspring mattress as this helps stop the coils from poking through. Firm wool or felt, or coir fiber are good choices for this part of a crib mattress and are better than polyester pads.
On top of the insulating pad is the cushioning layer. This is usually made with foam, cotton, or polyester, but may be made with wool or latex. Polyester is cheapest but tends to form pockets which make the mattress less durable and potentially unsafe for an infant.
An innerspring mattress with a layer of Dunlop latex, topped with wool and a layer of cotton, plus a waterproof cover made with polyethylene is my top choice for a lightweight, eco-friendly, non-toxic crib mattress.
The Pros and Cons of Coconut Coir Crib Mattresses
Most coconut coir crib mattresses are actually a mix of coconut coir and latex (sometimes natural, sometimes synthetic). Together, this mixture provides excellent firm support for a sleeping infant and it’s great that coconut coir is a renewable resource which is largely considered a by-product of the coconut water industry.
Consumer Reports have recommended coconut coir as an excellent material to make the insulating layer on top of innerspring coils. A thick insulator pad helps keep coils from poking through and a coir fiber pad appears to be much more durable than pads made with woven polyester. Polyester pads tend to form pockets and become concave in areas of the mattress frequently used. For a crib mattress, this could create a safety hazard for infants.
Downsides to coir mattresses
Coconut coir mattresses are a lot heavier than an innerspring mattress and may trap carbon dioxide. This could mean that a coconut coir mattress increases the risk of rebreathing carbon dioxide.
A ‘breathable’ tea tree bark-filled mattress marketed in Australia in the 1980’s and ‘90’s increased re-breathing of carbon dioxide and was associated with an increased risk of SIDS (sudden infant death syndrome).
There’s no evidence that coconut coir mattresses also increase SIDS risk, and the higher risk of SIDS associated with tea tree bark may be due to other factors, such as natural off-gassing. However, I’d still be suspicious of mattress marketing that claims a coconut coir mattress is more breathable.
There’s also no evidence to show that a coconut coir mattress is better for dissipating heat. This undermines claims that such mattresses reduce the risk of SIDS associated with overheating.
Note, too, that coconut coir is usually blended with latex. This is great if it’s natural latex, but many companies don’t specify if the latex is synthetic or natural. Looks for a GOLS certification or equivalent to verify it is natural (ideally organic) latex. Synthetic latex can contain some toxic chemicals and is not eco-friendly.
There’s another potential health hazard with coconut coir: the effects of processing coconut coir on workers’ health. Workers handling coconut coir are at higher risk of respiratory and pulmonary symptoms (R).
Where possible, buy coconut coir products that are certified Fair Trade.
All in all, a mattress containing coconut coir isn’t a terrible idea, but it is unlikely to be quite as magnificent as manufacturers would like us to believe and may pose a health risk for workers.
Best avoided: Polyurethane
I don’t recommend buying a mattress made with polyurethane foam, but if you are considering a foam mattress there are ways to make a safer choice.
Where is it made?
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 lb. to more than 5.5 lb. per cubic foot. Foam under around 3 lb. 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.
Is it certified?
Various certifications offer some assurance that the toxic chemical content of a foam mattress is lower than for similar products. So, if you’re buying a foam crib mattress, look for Greenguard Gold or Oeko-Tex Standard 100 or 1000 certification.
These certifications don’t guarantee that a product is non-toxic or eco-friendly, but they do suggest that a product might be a tad less problematic than its uncertified counterparts.
What makes it flame resistant?
Finally, you’ll want to check how a polyurethane mattress meets federal fire safety requirements. If a product is coated in chemical fire retardants, avoid it.
Instead, look for a mattress with an outer cover made with rayon, silica and Kevlar. Check that this doesn’t just apply to mattress seams. While these materials aren’t eco-friendly, they can help to reduce the amount of chemical treatment a mattress requires to meet fire safety standards.
Final thoughts on crib mattress materials
Finally, remember that natural and organic materials are subject to organic processes, and these organic processes are not always harmless. Wool, coconut coir, cotton, and other natural fibers can create a lovely home for microbes and bugs, as can polyurethane foam and other synthetic materials.
Wherever possible, ensure your baby’s crib mattress is well protected against moisture and undesirable critters and single-celled organisms with an effective waterproofing strategy such as polyethylene, which will also keep out bugs.
FAQs
Wool puddle pads are very popular, and for good reason. You can place this single sheet of wool on top of a waterproof mattress and under a cotton cover sheet for added protection against leaks and messes. It’s easy and quick to remove a puddle pad after an accident and the pad can be rinsed and hung to dry as needed. This usually means you only have to give the waterproof mattress cover a quick wipe down to keep it clean.
Because cotton absorbs moisture and wool wicks it away, it’s a good idea to combine a cotton pad on top of a wool pad to minimize the potential for wetness to penetrate the wool pad. Be sure to check that any wool puddle pads are 100% certified organic wool as some pads contain synthetic fibers. The two best options I can find are Holy Lamb and Home of wool.
Polyethylene is the plastic used to make grocery bags, toiletry bottles, sandwich wrap, and even bullet proof vests. The strength of the plastic depends on its molecular structure, which basically consists of a long chain of carbon atoms with two hydrogen atoms attached to each carbon atoms. Once this chain begins to branch off into other chains, the plastic becomes softer.
While it’s often touted as being non-toxic and entirely safe, polyethylene is still a synthetic material produced using potentially problematic chemicals. The chemical reaction required to create polyethylene seems to involve a transition metal catalyst, like TiCl3, or titanium trichloride, and co-catalysts such as group III metals like aluminum.
The type of low density polyethylene used for waterproof mattress covers does not typically contain bisphenol-A (BPA), a known endocrine disruptor.
TPU is made from polyether, polyester, or polycaprolactones, while polyurethane is made from polyols and isocyanates. If there are monomers and catalysts left over from the polymerization reaction(s) and other processes used to create TPU, there’s a chance that these could pose a risk of toxicity.
Additionally, other chemicals may be added to TPU which could compromise its safety. And, as TPU breaks down, it can produce unsafe degradation products including toxic gases and dust. Furthermore, like polyurethane, burning TPU produces irritant toxic fumes, meaning that any mattress made with TPU will probably have been treated with flame retardants.
Bamboo is an incredible renewable material and can be non-toxic and eco-friendly when used in certain ways. As a fiber for textiles such as a crib mattress, however, bamboo is generally not eco-friendly or non-toxic.
Bamboo rayon or viscose is typically processed with harsh chemicals in an energy intensive way to break down those tough natural fibers. Bamboo rayon, rayon, or Tencel are not eco-friendly materials and are instead synthetic fibers made from bamboo. So, don’t be fooled by greenwashing.
In addition, bamboo is not waterproof. This means that a bamboo mattress cover won’t protect against messes and leaks and can leave a crib mattress vulnerable to mold, mildew, and infestation that can harm your child’s health.
Coir fiber is a good material for a crib mattress insulator pad as it is strong, firm, and durable. Fiber wrap or rag or ‘shoddy’ pads are also used and are cheaper and, some argue, just as effective. Woven polyester pads are liable to form pockets over time and should be avoided as these may create a safety issue for infants. Hard, pressed felt is also used as an insulator and can be an excellent material choice.
When looking at mattresses, it’s important to determine if the latex is Dunlop or Talalay. Dunlop tends to be firmer feeling than Talalay which provides excellent soft support and pressure relief for adults but may be too soft for infants.
Latex crib mattresses are relatively easy to care for. You can usually just wipe down latex with warm soapy water, dab dry with a towel, and let it air dry. Still, I’d highly recommend using a waterproof food-grade polyethylene cover for any crib mattress, along with easily removed and replaced wool puddle pads.
While some infants do develop an allergy to latex, this is largely attributed to latex in bottle teats, pacifiers, balloons, nose cleaners, and medical equipment, with no documented cases of an allergy arising from sleeping on a latex mattress (R). Indeed, it is rather unlikely that an infant would even come into contact with latex from a latex mattress as these are typically covered in a layer of wool and cotton ticking and dressed with a waterproof cover and fitted sheets.
In addition, the latex used for medical equipment, pacifiers, gloves, condoms, and so forth is quite different to that used for mattresses. This latex, which is typically stretchy, is cold-dipped and still contains proteins that can trigger allergy. The types of latex found in mattresses undergo significant washing and a flash-heating or vulcanizing process that first eliminates a large amount of the proteins in the latex and then destroys any remaining proteins.
So, an infant seems much more likely to develop a latex allergy from repeated exposure to latex in a healthcare setting or even from using a pacifier, feeding bottles, or handling a party balloon than they are to have issues with a latex mattress. And, unless there’s a family history of latex allergy, or if an infant or caregiver has a known latex allergy and might touch the mattress in its uncovered state, there’s little reason to rule out a latex crib mattress.
Indeed, the only study I could find that looked at real-life exposure to natural latex found that there was no difference in the development of latex allergy in children who slept on a latex mattress compared to those who slept on a non-latex mattress (R). Most other studies look at immune responses when latex is frozen, crushed, ground up, mixed with solvents, and mixed directly with blood. Unless you’ve got some odd plans for your mattress, then, this exposure scenario seems rather unlikely.
Even if covered by a sheet, soft materials or objects, such as pillows, quilts, comforters, or sheepskins, should not be placed under a sleeping infant. Sheepskins are too soft for infants and could create a suffocation hazard; they should not be used for infants younger than 1 year, as advised by the American Academy of Pediatrics and many other organizations.
While very eco-friendly, kapok, is a no-go for crib mattresses. Kapok is far too soft and won’t create the required firm surface an infant needs to sleep safely. You may find kapok in the toddler side of a dual-sided crib mattress, however, so be careful which side faces up if an infant will be sleeping on the mattress.
If you’re looking into crib mattress material safety, you may have come across this Cochrane Review from 1993. The review found that the risk of SIDS was greater among infants who slept prone on natural fiber mattresses (odds ratio, 6.6) than among infants who slept prone on other types of mattresses (odds ratio, 1.8). While this sounds bad, the data also showed that a natural fiber mattress was not itself an independent risk factor for SIDS, with no greater risk found in infants sleeping on their back on such mattresses.
Also, when you dig into the data, it quickly becomes clear that the natural fiber mattresses included in the review were much softer than the foam mattresses (and much softer than most standard crib mattresses made with natural materials). The mattresses in the review were made with a kapok stuffing or ti-tree filling that compressed considerably and left an indentation. This suggests that an infant sleeping on their side or tummy could quite easily sink in too much and struggle to breathe.
Thankfully, natural fiber crib mattresses are much firmer in general these days and don’t pose the same safety risks. And, as always, infants should be placed to sleep on their back, not on their tummy or side.
Beware mattress marketing touting the benefits of ‘eco-foam’ or soy-based foam. These so-called green mattresses or plant-based mattresses are still made with petroleum-based polyurethane foam. The difference is that the company throws in a little soy oil (usually less than 20%) so they can call it eco-friendly. These foam mattresses are still highly flammable and riddled with toxic chemicals, including the flame retardants usually required for them to meet federal fire safety standards.
Coil count isn’t all that matters for a crib mattress. Industry experts generally suggest looking for a coil count of around 135-150 and a steel gauge of 15.5 or below.
Why? Because while one mattress may have 80 coils and another 250, the 80-coil mattress may be firmer than the one with the higher spring count if the coils are made with thicker (higher gauge) steel. Gauge varies typically from 19 to 12.5, with the lower number indicating a thicker coil.
Hi, thank you for this interesting read. We are looking to buy a mattress for our baby to sleep on when we transition from her crib to her room. We are considering a floor bed with an adult-size latex mattress. Is there any difference between a latex mattress in adult size and in children’s size that would make it unsafe for her to sleep on the adult size?
Hi Rose,
My apologies for the slow response.
I’m assuming your baby is toddler age and plenty old enough to be out of a crib – i.e., has long passed milestones such as rolling over by herself and is able to sleep without being contained in some way. If so, my only suggestion would be to consider getting a slightly firmer mattress than you would typically for an adult with greater body weight. Or consider a layered mattress that can be rearranged as she gets older and wants a softer sleep surface (saving you money and saving resources in the long-run!).
Oh, and be ready for her migrating from her bed to your bed at all hours!
Hope this helps,
Leigh
Hope that helps,
Leigh