What is Memory Foam?
Memory foam, also known as visco-elastic foam or viscoelastic, is a substance originally designed back in the 1960s for NASA to use for their aircraft seats. Viscoelastic is soft and highly energy-absorbing, making it ideal for absorbing impacts in aircraft crashes. However, it was soon turned into a material perfect for mattresses.
You see, when memory foam heats up (from exposure to body heat), it softens enough that it molds to the pressure of whatever is applying the heat. However, once you remove the pressure, it returns to its original shape. It’s called “memory foam” because it “remembers” its original shape after your body heat and weight are removed.
The type, density, and properties of each memory foam mattress will be different according to the manufacturer—and even the model, in some cases. The formula of viscoelastic changes the quality and firmness of the foam, so there’s no “one size fits all” type of memory foam. However, the good news is that this variety makes it easier to find the right memory foam mattress according to your unique needs.
Are Memory Foam Mattresses Safe?
Memory foam is made from chemical ingredients (unlike natural latex), so many people have voiced concern that the chemicals can be toxic. If you’ve ever smelled the off-gassing—the release of airborne chemicals from the foam mattress—you’ll know just how strong and potentially toxic memory foam can smell.
We’re not going to get into the complex list of chemicals used to make memory foam mattresses—from polyurethane to polyols to blowing agents—but instead, we’re going to look at the potential risks of using memory foam.
Some of the chemicals in memory foam that may cause negative side effects include:
- Methyl benzene, which may cause lung irritation when inhaled
- Methylene dianiline / MDA, a suspected carcinogen and potentially irritating to your skin and eyes
- Acetone, which can be toxic in high quantities, but will have limited side effects in small quantities
- Formaldehyde, which isn’t usually added to memory foam, but may be a byproduct of the chemicals used
- Dimethylformamide, which may be a carcinogen
The good news is that memory foam mattresses contain VERY minimal amounts of these chemicals. All of them are present in the various types of memory foam, but in such small quantities, the risk of health problems or side effects is minimal.
“But,” you may be thinking, “all memory foam mattresses produce a nasty toxic smell when off-gassing. Nothing that produces a smell like that can be safe, right?”
Off-gassing is just the result of the breakdown of volatile organic compounds in the memory foam. They create a gas that remains trapped in the mattress’ bag or box. When you open it, that gas comes out and smells pretty nasty.
Thankfully, off-gassing from memory foam mattresses is perfectly harmless. Unpleasant, certainly, and dangerous if not ventilated, but overall harmless.
It is recommended that you air out the mattress for a few hours or even overnight before you use it. Off-gassing can cause problems like eye and throat irritation, headaches, breathing difficulties, and nausea, but once you air out the mattress a bit, you’ll find these initial side effects go away.
Are Memory Foam Mattresses Good for Your Sleep?
When it comes down to it, really the most important thing we look for in a mattress tends to be comfort. We need good back support, the right firmness, and materials that will last a long time. All of these things come together to determine the comfort level of a mattress.
Most of us are accustomed to sleeping on spring mattresses, but you’ll find that memory foam offers far better sleep for a number of reasons:
Pressure Relief – The fact that the foam molds to your body means all of your weight is distributed evenly across the mattress’ surface, rather than just on your back, neck, hips, shoulders, and knees. This reduces the risk of soreness and numbness and helps you sleep far better every night.
Posture Support – No matter how you sleep—on your back, side, or stomach—the memory foam mattress will conform to your body and provide support for that sleep posture. For those with back pains, memory foam is the ideal solution. The medium-firm texture can help to drastically reduce spinal pain, making it much easier to sleep comfortably and roll out of bed in the morning ache-free.
Durability – Memory foam mattresses will last a lot longer than simple spring mattresses (see the section “How Long Does a Memory Foam Mattress Last?” below for more information). You’ll get nearly twice the lifespan, all thanks to the durability of the viscoelastic foam.
Hypoallergenic – While the section above did list a few downsides to the chemical foam, the good news is that once the mattress has completed its off-gassing, there is very little risk of further side effects. In fact, you’ll find that it’s surprisingly hypoallergenic and resistant to dust mites and bugs. After all, the mattress is made of solid blocks of foam, so there’s no way any dust mites or bugs can get inside. Mold and pet dander will never get inside your mattress, and the materials are hypoallergenic for those with allergies to wool, feathers, and other fibers.
Better Circulation – Because there is no pressure being applied to specific points on your body, there is no risk of cutting off blood flow. And the fact that your weight is evenly distributed means your blood will be able to flow more easily. Memory foam is far better for those with circulatory and cardiovascular problems than a spring mattress.
Low Maintenance – With memory foam, you simply need to rotate the mattress 3-4 times per year to ensure a long lifespan. There is no risk of a spring busting and stabbing up through the mattress, and you definitely don’t have to worry about it sagging. It’s the ideal mattress for those who want a low-maintenance, hassle-free solution.
No Motion Transfer – For the spouses or partners of those who move around a lot at night, memory foam is a godsend. The foam won’t bounce like springs do, so there is no motion transferred when your partner moves, shifts in bed, or gets out of bed to use the bathroom. This means far less likelihood of interrupted sleeping.
Drawbacks of Memory Foam Mattresses
Of course, memory foam isn’t perfect. There are a few reasons that you may want to consider spring, pocket coil, natural latex, or gel foam mattresses instead:
Pricey – Memory foam mattresses tend to cost 10-35% more than spring/pocket coil mattresses, and they can often be pricier than natural latex and gel foam as well. They’re worth the cost, but prepare for a higher initial investment.
Hot – Memory foam molds around your body to form a comfortable cradle, but that unfortunately traps your body heat near your skin. It’s marvelous in the cold winters, but during the hot summers, you may find yourself overheating quickly because of the temperature-sensitive foam. You may need cooling gel mattress pads to reduce sweating.
Smell – Off-gassing is definitely one of the worst parts of memory foam mattresses. It’s recommended that you air out the mattress at least 4-8 hours before use, and it’s better if you can leave them in well-ventilated rooms for no less than 72 hours right out of the box. The chemical smell can be very strong and irritating at first. Cheap memory foam is often even more pungent, as the low-grade foam is made with stronger chemicals.
Quicksand Feel – The foam tends to soften to mold to your body, but it stays soft as long as your body heat is present. Some people dislike this, as it can feel like you’re trying to move through quicksand. The memory foam will be so soft that you’ll sink into it as you shift or change positions. Usually manufacturers combat this by adding a more solid layer of foam beneath the uppermost memory foam layer, but it doesn’t always help. Memory foam can also take longer to bounce back to its original form.
Definitely not deal-breakers, but a few drawbacks you need to know about before going ahead with a memory foam mattress!
Memory Foam vs. Gel Foam: What’s the Difference?
Gel foam is the latest mattress material on the market and it has become “all the rage” among savvy consumers.
Basically, gel foam is the same viscoelastic material used for memory foam, but it has gel infused into it. The gel beads mixed into the viscoelastic solves memory foam’s #1 problem: overheating.
You see, the beads aren’t solid like the foam itself, so there is space for air to pass through the beads and escape the mattress. The gel is also made with a special material designed to draw body heat out, so it doubles down on the cooling effect. For those who sleep hot at night, gel foam can do wonders to keep you from overheating even in summer. You’ll get a much cooler night sleep—at a significantly higher cost, of course. Gel foam mattresses cost 5-20% more than memory foam mattresses.
How Long Does a Memory Foam Mattress Last?
Mattresses are pricey investments, so you want to make sure the mattress you buy lasts as long as possible.
The various types of mattresses each come with their own life expectations:
Spring mattresses tend to have a lifespan of 5-7 years, with pocket coil mattresses lasting around 8-10 years.
Latex mattresses tend to have a longer lifespan. Natural latex will last for around 12 years, with some lasting up to 15 years due to the higher durability of the natural material.
Memory foam has an average lifespan of 8-10 years, though some can get more with proper maintenance and regular rotation. High-density memory foam lasts much longer than medium-density memory foam.
A Buyer’s Guide to Memory Foam Mattresses
If you’re in the market for a good memory foam mattress, here’s a complete guide to finding the mattress that suits you best.
Know Your Foam – Memory foam comes in three different types:
- Traditional memory foam, which is the viscoelastic we’ve been talking about since the beginning. This is the cheapest and most readily available type of foam, but it’s the type most prone to overheating.
- Gel memory foam, which is memory foam infused with gel beads. This memory foam can reduce pressure points and is far more effective at dispersing body heat than traditional memory foam.
- Open-cell memory foam, which is basically memory foam with an open cellular structure that allows air to flow in. This is also far more effective than traditional memory foam at dispersing heat, and it has a quicker response to your body heat and pressure. You’ll find it adapts to your body more quickly so you don’t feel like you’re slowly sinking into the mattress—a common reaction to memory foam.
Know Your Layers – All memory foam mattresses will typically be made using multiple layers of not only memory foam, but other types of foam or, in some cases, pocket coils.
Memory foam is typically used for the “comfort” layer, the top layer, and the thicker, denser materials are typically used for the core and base of the bed.
The inner make-up of the mattress will have a direct effect on price. Higher-density foam (5 pounds per cubic foot rather than 1-3 pounds per cubic foot) will last far longer, even if it doesn’t directly affect the feel of the mattress.
Know Your Sleep Habits – Are you the type of sleeper that moves around a lot, or do you stay in one position all night?
For those who move around a lot, you may want to look into a type of memory foam that has a higher density and can provide you with a stable, solid surface to push off of as you move around. That way, you won’t get that “quicksand” feel.
For those who sleep in one position all night, you may be better off with a lower-density, softer memory foam. That way, the foam will adapt to the contours of your body and form a sort of cradle for maximum comfort and optimal support.
Know Your Body Temperature – If you are a hot sleeper, you’ll definitely want to consider either open-cell memory foam or gel memory foam for the comfort layer of the mattress. Remember that memory foam traps heat near your body, so you’re very likely to wake up a sweaty mess if you’re sleeping on traditional memory foam.
However, if you tend to run cold even in the summer, you’ll want a traditional memory foam mattress that will trap as much body heat as possible.
Know Your Sleep Position – The position you sleep in will determine whether or not memory foam is ideal for you.
Those who sleep on their backs will find that memory foam does wonders for spinal alignment. The memory conforms to the contours of your back to form a cradle that will keep you comfortable all night long, with your spine in the proper position.
Those who sleep on their sides will also find that memory foam is a great choice. The soft, conforming foam will cradle the hips to reduce pressure points, a common problem in this position. You’ll get a more comfortable angle on your hips, spine, and legs as you sleep, encouraging better spinal alignment and reducing your risk of lower back pains.
For stomach sleepers, however, memory foam isn’t your best choice. When your stomach and chest sink into the mattress, it can create a strain on your lower back, neck, and shoulders. Even if you only spend a few hours sleeping on your stomach every night, it’s important you’re aware that memory foam isn’t best for the face-down position.
A Unique Sleep Solution: Memory Foam Mattress Pads
Memory foam mattress pads, also known as memory foam mattress toppers, are an excellent option for those who want solid support but the added comfort of memory foam.
Basically, these are pads that you put atop your existing mattress in order to provide an added layer of memory foam comfort. The block of memory foam will be anywhere from 2 to 4 inches thick, and it simply sits on top of your mattress.
Thinner (2-inch) mattress pads are great for stomach sleepers who want to reduce pressure points when they sleep on their back and sides. Medium thickness (3-inch) mattress pads are better-suited for those who have firm mattresses but want to provide a bit more comfort and spinal support. Thick (4-inch) mattress pads are typically used by heavier users (250+ pounds).
Fun Fact: Memory foam mattress pads can be used not only on your bed, but while camping. You’ll sleep a whole lot better!
It’s important to know that a mattress pad is NOT a better choice than a new memory foam mattress. New mattresses are always recommended if you’ve got an old mattress and are looking to upgrade your comfort. However, if you’re looking to make a fairly new (2-5 years old) mattress more comfortable and better for your back, it may be a smarter investment to simply add a mattress pad rather than buying brand new.