How Long Do Mattresses Last? The Results May Shock You!
Mattresses are pretty expensive — one quick glance at our buyer’s guide will confirm this fact. This is why many people do not replace them – not even after many years of use.
They do not want to spend a lot of money on a new one. Besides, now you can delay the process of buying a new one if you do an excellent job at maintaining your existing one.So, how often should you replace your mattress?
It doesn’t matter which type of bed you have. Most of them are ready for replacement within ten years to ensure a good night’s rest (old mattresses can hurt your sleep quality). Besides, it can last beyond ten years on average, if the owners maintain it properly.
Also, many different factors affect a bed’s lifespan. You can extend its life expectancy by following a few easy steps in the text below. We prepared and wrote down some tips to boost its longevity.
The Ins and Outs of Memory Foam: Is It Worth the Hype?
April 10, 2017
Filed under: Shopping Tips
Memory foam mattresses have soared in popularity over the last decade. Memory foam pillows are a more recent addition to the product line. But what’s so great about memory foam? A lot, it turns out.
What is memory foam?
Memory foam material dates back to 1966 when it was developed by NASA to absorb shock in airplane seats. Since then, “slow spring back foam” (as it was initially referred to) has been used in NFL helmets, hospital beds, shoes, and prosthetics.
Memory foam has evolved in recent years, and technologically advanced foams are common materials in mattress construction. For example, Serta’s gel foam mattresses are made up of a combination of tiny cushioning chambers, each infused with millions of Titanium gel beads uniquely designed to relieve pressure points, provide added support and aid in temperature regulation.
Why do some sleepers prefer memory foam?
Memory foam is a great mattress material for many reasons. It evenly distributes weight and pressure over an area, giving many sleepers pressure point relief. The foam contours to each individual’s body shape, allowing for a high level of mattress personalization. Memory foam is also resistant to movement. If your bed partner gets up frequently or tosses and turns at night, the activity doesn’t ripple throughout the entire mattress.
Now, advanced memory foam technology helps keep you cool while you sleep. Serta’s iComfort mattress collection, for example, features EverFeel® Triple Effects™ Gel Memory Foam which provides a cool and comfortable night’s sleep.
How long does memory foam last?
Memory foam mattresses can last anywhere from eight to ten years, depending on how well they’re cared for. Typically, a memory foam mattress will last as long as any other type of mattress, whether it’s an innerspring or hybrid.
A liquid resistant mattress protector is a good way to keep your memory foam mattress clean and free from stains, which can impact the warranty. Our iComfort TempActiv mattress protector is a great choice for your memory foam mattress due to its cool-to-the-touch feel and water proof barrier.
What if I’m still not sure?
That’s okay! A new mattress is a big decision. If you prefer the traditional feel of an innerspring mattress, Serta offers the best of both worlds. Our hybrid mattresses mattress models combine gel memory foam with the most advanced individually wrapped steel coil innerspring systems. No matter your comfort preference, we’ve got you covered.
How Long Does a Memory Foam Mattress Topper Last?
A mattress topper is a bedding item designed to be used on the top of your mattress to provide extra comfort and support, improve cleanliness, and prolong the lifespan of a mattress.
Toppers can be made from various materials such asmemory foam,latex, down, etc. and there are many different designs and structures that can suit different needs and sleep preferences.
Your topper should improve the support for your entire body and complement any sleeping position. It should also act like an extra cushion for your entire body, especiallymemory foam mattress topperand allow you to sink into it to prevent the appearance of pressure points and provide you with the peaceful and restful sleep every night.
However, if it causes you to wake up in pain or felling more tired than ever, then it may be that your mattress topper is getting old and that you should get the new one.
Read our article and learn more about memory foam mattress toppers as well as when and why you should replace them.
Table of Contents
How Long Does a Memory Foam Mattress Topper Last?
You would think thatmemory foam mattress topperscan last as long as the beds made of the same material, but this is not the case.
The average lifespan of mattress toppers, including those made entirely of memory foam, is 3 to 5 years.This is only the case with high-quality mattress toppers, whereas those made of cheap materials will only last a year or two.
The longevity of a memory foam mattress topper will depend on other factors as wellsuch as the weight being put on it, frequency of use, the thickness of the topper, the condition of your mattress, and how well the topper is maintained.
Heavier people may speed up the process by adding extra pressure to the memory foam topper.Memory foam mattressesusually contain a highly resilient core and high density base that make the top memory foam layers more durable, but the topper doesn’t have this.
Extra weight can also cause the open cells to crumble quicker than they would do under an average person.
The thicker the topper, the longer it will last.Thinner toppers usually wear out quicker, while the thick memory foam will last longer as it takes longer to break down over time, and it will also provide greater comfort.
The Condition of Your Mattress
As toppers are generally laid over an existing mattress, if the mattress underneath is old and in a poor condition; if it is already worn out and sagging in places, your memory foam topper will simply follow that contour and make the sage even more pronounced due to its soft and contouring nature.This will eventually ruin your mattress topper.
If your mattress looks like new, but you still experiencepainwhile sleeping, even with the new memory foam mattress topper placed on top, then you still may need to replace the mattress.
If your mattress is over 7 years old then it’s time for a new one, even if it doesn’t show any signs of a long use such as cracks, sagging, protruding wires, etc. because, like we have already mentioned, an old and uncomfortable mattress will decrease the comfort of your memory foam mattress topper and shorten its lifespan.
Frequency of Use
Memory foam mattress toppers in guest bedrooms will last significantly longer than those used every night.
The reason why toppers don’t last so long in bedrooms is because they are used a lot more than toppers in guest bedrooms. Spending 6 to 8 hours a night on them each night puts a lot of pressure on them which is why they wear out faster than those mattress toppers used on beds in guest rooms.
Maintaining Your Mattress Topper
Memory foam may be difficult to clean and maintain, butthere are ways how you can clean them and prolong their lifespan.
You should clean them at least once or twice a year by vacuuming them, spraying them with water and detergent solution, washing them, spot cleaning or using topper covers and washing these regularly.
Well maintainedmemory foam mattress topperswill last longer and serve your better than those that are not maintained at all.
If you avoid cleaning your topper, stains from food or drinks, pet urine, dust and accumulated debris and odor will eventually ruin your topper and render it useless.
How Long Do Memory Foam Mattresses Last?
Adequate sleep affects everything from your blood pressure to appetite control. Sleep provides a foundation on which to build your well-being, and a high-quality mattress physically supports the seven to nine hours of rest you need. A mattress is an investment in the future of your sleep health. But, how long should it last? What’s average? And how can you identify a mattress that will last longer than a few years?
The durability and longevity of a memory foam mattress depends on the density, firmness, and thickness of its foam layers. Armed with the right information, you can determine roughly how long a specific model will last, so you can ensure you’re making a worthwhile investment.
What is Memory Foam?
Memory foam is polyurethane foam made with chemical additives to give it viscoelastic properties. Most memory foam is made with petrochemicals to give it it’s signature contouring feel, but some brands replace portions of the petrochemicals used to normally make memory foam with plant-based oils, resulting in a more eco-friendly foam.
Memory foam stretches and compresses under heat and pressure to mold around the object pressing into its surface. If you think about a human body, the foam stretches under the pressure and heat, which causes it to conform and mold itself to the body’s curves.
The name “memory foam” stems from the foam’s ability to temporarily hold the shape of the object pressing into the foam. For example, if you were to press your hand into memory foam, the shape of your hand would remain for a few seconds after you’ve removed it. It’s almost as though it holds the “memory” of your hand’s shape.
The longer the heat and pressure continue, the more the foam adapts itself to the object. Consequently, sleepers experience greater contouring the longer they stay in one position on the memory foam. Once the sleeper moves, the foam returns to its original shape.
Memory foam mattresses cradle the body and relieve pressure at high-pressure points like the hips and shoulders. It reduces pressure almost anywhere on the body, including sore or painful areas. Its ability to mold to the body makes it incredibly useful for keeping the spine aligned, no matter the position of the sleeper. It’s found in typical memory foam mattresses, mixed-foam models, hybrids, and quilted to the covers of innerspring mattresses.
Memory foam is popular among side sleepers due to its ability to keep the spine aligned as the sleeper shifts throughout the night. However, in the right firmness and layer arrangements, it’s comfortable for back and stomach sleepers, too.
How to Determine Mattress Durability and Lifespan
Memory foam mattresses are among the most durable models on the market. Models with low-quality memory foam may begin to lose their ability to bounce back or return to their original shape within a few years, while high-quality memory foams may last 10, 15, or even 20 years.
Several factors go into determining the memory foam’s durability. The first and most important is density, but we’ll also cover foam indentation load deflection and layer thickness. We’ll also discuss how the mattresses warranty can help you make sure your new bed will last.
Density presents one of the easiest ways to determine the durability and lifespan of memory foam. Density, in reference to memory foam, is measured in pounds per cubic foot (PCF).
The low PCF memory foams breakdown the fastest, while high PCF foams have the best durability. However, you can’t determine a mattress’s overall density by a single layer alone. A low-density memory foam layer anywhere in the mattress will reduce the density and durability of the mattress as a whole. You can follow the general rule of the more high-density foams used in the mattress, the greater its overall durability. High-density memory foams cost more to produce, but they make up the extra cost in longevity.
A couple of things to remember when talking about density: 1) density does not equal firmness. A dense foam can be quite soft while a less dense foam may be firm, though the opposite can also be true; 2) memory foam naturally softens with age and use. However, high-density foams will continue to return to their original shape for a longer period of time than a low-density foam despite any softening.
Indentation Load Deflection (ILD)
Indentation Load Deflection may sometimes be called the Indentation Force Deflection (IFD) based on who is using the term. Whichever term is used, the ILD indicates the foam’s firmness. It involves a standardized test, wherein a 50-square inch machine compresses a 15 x 15 x 4-inch piece of foam to 25 percent of its original height.
A high ILD indicates a firmer foam, whereas a low ILD indicates a softer foam. A high ILD foam can have a high or low foam density. The same holds true for low ILD foams. However, the ILD can tell you what to expect from the feel and performance of the foam. Thicker layers will have a higher ILD because it takes more pressure to compress the foam to 25 percent of its original height.
What does ILD have to do with how long the mattress will last? Firmness doesn’t play as big a role in the longevity of the mattress as density. However, it’s smart to note both the density and ILD of each layer to not only determine the feel of the mattress but give you an idea of how it may take wear and tear over time.
Take note of where the low or high ILD foams are placed in relation to the layer densities. A low density, low ILD foam layer could mean the mattress breaks down and loses its desired firmness level faster. However, if it’s a thin comfort layer that’s followed by several thick, high-density layers, it may not affect durability as much.
The thickest, densest, and firmest layer in a mattress is the support core. This layer gives the mattress its shape and a good portion of the durability. However, a thicker mattress isn’t necessarily more durable than a thinner model.
Each layer’s density and firmness will come into play both in comfort and durability. Two mattresses of the same height and layer thicknesses may each have a different lifespan based on the density of each layer, for example. However, a single thin, low-density top layer may not play as much of a role in durability if it’s supported by thick high-density transition and support layers. Again, it’s about looking at the mattress as a whole and how it will support body weight over time.
It makes sense for mattress manufacturers to warranty their products based on how long they think the product with last. The average mattress warranty lasts ten years. Companies that offer 15, 20, 25, and lifetime warranties make mattresses they expect to last well beyond that 10-year average.
The warranty will include information about the kind of foundation and maintenance needed to properly maintain the bed.
Typical Memory Foam Mattress Lifespan
The average lifespan of a foam mattress is six to eight years. Models made with high-quality, high-density memory foams last substantially longer. There are memory foam models with 15 to 20-year lifespans and warranties. The combination of foams and material quality takes these models well beyond average.
The type of mattress makes a big difference in the lifespan too. In comparison to memory foam, the only mattress type that consistently lasts longer than high-quality, high-density memory foam are natural latex mattresses, which average eight to ten years. A hybrid mattress lasts about eight years, while innerspring mattresses last between six and eight years.
These are all rough estimates. Your personal circumstances will affect longevity, too. Heavier weight sleepers, for example, will experience a shorter mattress life due to the added wear and tear of more body weight.
Extending the Life of a Memory Foam Mattress
Foundation and Support
Mattresses need a proper foundation for them to last as long as promised by the manufacturerandfor them to be comfortable. Each manufacturer has their own guidelines, but you should check whether the mattress can be used on a solid, slatted, or adjustable foundation. Most modern mattresses do not require a box spring, but if you like having one, they’re still available.
The manufacturer may also specify the distance needed between slats and whether there’s a need for center support post. Most of the time, the warranty only remains valid as long as the mattress is appropriately supported and with good reason—improper support may cause premature sagging, indentations, or loss of shape.
Memory foam softens over time. To standardize the wear and tear, some manufacturers specifically recommend rotating the mattress from head to foot once a month for the first six to twelve months and every few months thereafter. Others may recommend rotating more or less or not at all.
There are a few double-sided or flippable foam mattresses as well. These models have different firmnesses on each side. You may only need to flip it if you want to change the firmness.
One of memory foam’s benefits is its natural ability to resist dust mites and other allergens. However, mattresses should still be regularly cleaned. Removable, machine washable covers should be periodically laundered. However, you can save yourself on cleaning by always using a mattress protector or pad. It’s much easier to launder and replace a mattress protector than it is a mattress cover.
Liquids should be soaked up and cleaned immediately. Vacuuming the surface of the mattress to remove dust and debris every few months can also extend the mattress’s life.
Memory Foam Mattress Price
Memory foam mattresses start for as low as $200 and go up to over $2,000. At the entry-level, between $200 and $700, you’re looking at models with less dense foams because less dense foams are inexpensive to produce. Some of these models will be as comfortable as higher-end mattresses, but they won’t last nearly as long. And, others may not make it to the average six-year mark before indentations or sagging begin to show.
In the mid-range, from $700 to $1,200, there’s a wide selection of mattresses that balance the quality of materials with the price. You’ll see higher density foams throughout these models, which gives them better durability. These models may also have extra cooling features like gel, copper, or graphite to enhance breathability.
At the high end of the memory foam market are $1,200 to $2,000 mattresses and some that are close to $3,000. These models may have more layers with varied firmnesses and densities that extend the life of the mattress.
Memory Foam Durability: The Bottom Line
- With the right foams, memory foam mattresses can be incredibly durable, lasting well over the six to eight-year average.
- Density provides a quick way to gauge the foam’s overall durability. However, you have to take into account all of the mattress’s layers and materials to get a better idea of its overall longevity.
- The warranty tells you how long the manufacturer expects the mattress to last.
Memory foam mattresses can be an excellent investment in your sleep health. When you know what you’re looking for, you could have a new mattress that relieves pressure and cushions you into a better night’s rest for years to come.
This article is for informational purposes and should not replace advice from your doctor or other medical professional.
Memory foam – pros and cons
Visco elastic foam or "memory foam" is a very different material and perhaps partly because it has such unusual qualities compared to the many other materials used in mattresses, there is also a lot of misinformation "disguised as fact" about it. It is also subject to many different "formulas" in its manufacturing by different companies which change its qualities . for better or for worse . and this too becomes the subject of lots of the hype and misinformation you will hear in the world of marketing and selling mattresses.
What are the basic differences in materials used in a mattress?
There are two basic ways that a material in a mattress reacts to weight and pressure.
1. Viscous materials tend to flow away from pressure like a liquid or honey and tend to distribute and absorb energy
2. Elastic materials tend to store energy under pressure and to different degrees push back against compression
Materials like Water and Air, are viscous.They do have some pushback in a mattress enclosure but this comes from the elasticity and resilience of the enclosure or from other materials in the enclosure that holds them not the air or water itself. Viscous materials can be very hard initially with sudden pressure but feel much softer under more gradual pressure (try leaping onto an airbed or waterbed core). This is because viscous materials take time to "give way" to pressure. When they do give way, they give way in any available direction (out to the sides for example) and spread the pressure out through the layer.
Springs and non memory foams (like "normal" polyurethane and latex) are elasticand will recover quickly and with different amounts of "force" behind them (based on how quickly they spring back) to their original shape or length. Both are also breathable enough that the air just goes in and out with little to no resistance in either direction (compression and recovery) so the response from both of these are mainly because of the material itself not from what encloses them (although this will also have some effect). Of course foam has some resistance to airflow in both in and out directions so airflow plays a small part in its qualities while innersprings are not at all affected by air. Compression of an elastic material works in real time so it would initially feel much softer than a viscous material if you leaped on it but it only gives way in one direction (underneath you) so it will store energy underneath you (and push back) and may feel softer initially but firmer than a viscous material after a matter of some seconds. They have "bounce" in other words and this bounce is called resiliency.
Natural fibers are elastic and resilient to much lesser degrees but not viscous.They are very breathable so the air in them would flow away easily as they compress under pressure but the fibers are not nearly as elastic (stretchable) or resilient (bouncy) as non memory foam or springs and don’t "recover" as easily (horsehair is the most resilient of the commonly used fibers and recovers more strongly than wool which recovers more strongly than cotton). These are so breathable that there is very little resistance to air flow under compression (the air inside them moves away really easily) but since most fibers don’t have the resiliency to recover with as much force as springs or most foams and are less elastic, they will become more "permanently" compressed to differing degrees over time. They tend to need a resilient support layer underneath them.
Memory foam has a combination of viscosity and elasticitywhich is why its often called "visco-elastic" and is so different from other materials. It is made in such a way that its ability to recover over time (a period usually measured in seconds) is strong enough (even though it is slower) to "refill" the air but it is not strong enough to be resilient so it absorbs the energy of compression more than returns it with a "springy" feeling. It is less breathable and in the same way that it is more difficult to breathe in or out through a thick fabric, under compression the air both leaves and comes back against more resistance than most other foams. This is part of why it is slower than other materials to compress and return. Memory foam also softens in response to heat and humidity from your body or room temperature as it changes from from a more elastic material into a more viscous material and the length of time it is continuously compressed can also affect how much the memory foam softens as well. This change or "melting" also takes time when you lie on it and it also takes time to change back to elasticity and return to its shape when you get up. These two factors are the main reasons that lead to the slower compression and recovery (the memory quality) of memory foam. It also needs a good support layer underneath it.
Materials in a mattress that absorb compression forces and redistribute pressure away from pressure points are great for pressure relief but not usually as good for support.Layers that store energy and push back can also be very good at pressure relief in softer versions but are also better for support. This also depends to some degree on the point elasticity of the material and its ability to form a conforming cradle that mirrors the shape of the body. All viscous materials are good at this. Some elastic and more resilient materials are better at this than than others. The different layers in a mattress are usually designed in such a way that the complete mattress will have both supportive qualities and pressure relieving qualities. The core of the mattress which is the middle and bottom parts (usually innersprings, latex, or higher quality polyfoam) is the part that is primarily responsible for supporting the heavier parts of your body and keeping them from sinking in too far. The comfort layers which is the few inches (usually polyfoam, latex, memory foam, natural wool, horsehair, or synthetic fibres) are responsible for redistributing pressure so you don’t get "pressure points" when you sleep. They are also responsible for supporting the inner or more recessed parts of your body (like the small of your back, waist, upper thighs etc) so that gravity doesn’t pull them down against the natural position or curvature of your spine. These parts of your body don’t usually sink in enough for the deeper support layers to truly support them.
So what does all this mean in mattress terms?
Its unique combination of qualities leads to the advantages of memory foam for some .
Memory foam’s greatest advantage, because of its combination of properties, is generally considered to be its ability to distribute and relieve pressure.This does not mean however that it is dramatically better than the best of other materials as there are other types of foam like latex or high quality polyfoam that in their softer versions through compression alone are very close to memory foam in their ability to distribute pressure to levels below personal detection for most people. Even natural fibers that have broken in and formed a "cradle" to your body can distribute pressure very well and are often used in high quality mattresses. I should also mention here that there is one other material called "buckling gel" that in some cases may even be superior to memory foam or latex in terms of pressure relief but it is newer, not as common, and rather expensive. If a mattress relieves pressure below levels that you personally can detect, then which material is used in the comfort layers to do this is not so relevant except for other reasons such as its ability to support, its breathability, and its durability. In hospital applications (such as the relief of pressure sores) or with highly sensitive people, this slight difference in pressure relief can be more important however in most applications the difference is not as critical or even noticeable and the difference in materials used for pressure relief is more about how they feel and personal preference.
Another advantage of memory foam over a liquid or air is that memory foam requires body heat (in differing degrees with different formulations) to become viscous enough to "flow"so the "unmelted" areas of foam that are further away from your body will be firmer and resist pressure without "flowing away" from that pressure. This means that you are enclosed in a "stable cradle" of material that is "softer" close to you while it remains "firmer" further away from you. This combination of softness and firmness feels very good to people who like to sleep "in" a mattress that also feels "stable". Without this ability and the difference in viscosity and elasticity in different parts of the mattress, you would be sleeping "in" a viscous material which felt more like water or jelly without the feeling of "stable softness" that comes from a good memory foam layer. Other more elastic foams and natural materials to greater or lesser degrees are able to combine a feeling of softness with stability as well but memory foam is the leader here.
The qualities that provide this "stable cradle" effect is also connected to another of memory foam’s attractions to some which is its ability to isolate movementbetween people sleeping on a mattress. Its ability to absorb energy and isolate movement is better than most other materials because of its ability to both absorb energy and respond locally to movement. Latex in a comfort layer is also excellent here because of its ability to "localize" compression better than other materials but it doesn’t absorb energy nearly as much. Latex, certain high quality polyfoams, and certain innersprings (like pocket coils) in the support layers also contribute to a mattress’ ability to isolate movement and what is under your memory foam is important if this is a desirable part of a mattress’ qualities for you.
Memory foam, at least if it is a good quality and higher density memory foam (5 lbs density or above), is also more durable, will keep its qualities, and last longer than many other polyfoamsthat are typically used in a mattress, especially in the upper comfort layers. It is not unreasonable to expect the best quality memory foams to last 8 – 12 years (depending on its use and the "stresses" it is exposed to). This is not as long however as some very high quality polyfoams, latex foams, better quality innersprings, or natural fibers used in "upper end" mattresses, all of which can last longer without breaking down.
The same combination of qualities which are attractive to some can also be responsible for memory foam’s weaknesses for others .
Because of its low resilience, memory foam is a poor deep support material(the part of your mattress that supports the heavier parts of your body that want to sink in more). This is why it is so important to pay attention to the layers underneath the memory foam in a mattress as this is where the deep support (ability to keep your spine aligned) comes from. Treating memory foam as "supportive" as opposed to "pressure relieving" will usually lead to a potential purchaser paying less attention to underlying parts of the mattress and their resilience and other qualities, and possibly choosing a mattress with a poor ability to provide good alignment for a particular body weight distribution and/or different sleeping positions. Because memory foam can allow you to keep sinking in further over the course of the night as it softens, the underlying parts of the mattress that will prevent your heavier parts from sinking in so far that your spine is out of alignment is also important and some mattresses that have thicker layers of memory foam may keep you in good alignment when you first go to sleep at night but you may be out of alignment when you wake up in the morning.
Some side effects of memory foam’s greater sensitivity to heat can also lead to sleeping issues for some people.The deeper in a mattress someone sleeps, the more likely someone is to have issues with "sleeping hot". This of course is a quality of all foams where you "sink in" to some degree but it is compounded by the makeup of memory foams in general which allow a greater degree of sinking in and are typically less breathable (allow for less evaporation) than other foams. Even the newer generation memory foams which are more breathable (and usually a little "quicker") tend to be less so than other foams that are readily available. The greater breathability of other foams which have a more "open" cell structure (like latex or other polyfoams) tend to lessen the heat issues even for those who like to sleep more "in" a mattress using softer "non memory" foams. Natural fibers breathe best of all and tend to be cooler than any foam . especially memory foam.
This same sensitivity to heat can also lead in some cases to a mattress becoming "too soft" or "too hard" depending on the external temperaturein your bedroom, and can change its feel from season to season or from what you experienced in the store depending on environmental conditions. Different types of memory foam can be more or less sensitive to this but it can be more important to control the temperature of your bedroom with some memory foams than it is with others or with other materials.
Another potential issue of memory foams is that they take more time to adjust to different positions.This can be an issue for those who change positions often or are sensitive to the time it takes for the memory foam to conform to their new position as it can create short term "pressure" while it forms a new "cradle". Again different types of memory foams will take shorter or longer to conform to a new position. This "time to compress" or "rebound" that changes with temperature is both part of memory foam’s strength for some (creates a "stable cradle") and its weakness for others (doesn’t conform to new positions quickly enough or feels too firm). Some people may also be sensitive to a lack of resiliency or "pushback" which allows them to change positions more easily with a little "help" from the mattress and helps to support the lumbar area. This same lack of resiliency or "springiness" is also why it is often rated lower than other materials for the "other activities that take place on a mattress".
Finally there are the "offgassing issues" of some of the poorer quality foams that are common in the market today.While all memory foams and polyurethane foams in general (including the "green" ones) use some "nasty" materials in their manufacture, some of them have more of this material left in them by the time you sleep on them than others. For those that are sensitive to this offgassing, this can lead to issues ranging from a reaction to the unpleasant smell itself all the way to respiratory issues caused by the vapors. Your best protection against this is to make sure you know who manufactures the memory foam used in a mattress and not just accept the "re-branded name" that has been given to it (and to you). If the foam in your mattress has been certified by Certipur or Oeko-tex (or a similar organization), you can be reasonably sure that at least any smell or offgassing that you may notice has been tested for any potential harm it may cause you (within the limits of the test). More natural materials used in mattresses such as different fibers and good quality latex foam (which may also have a less unpleasant odor for a short time and is usually tested as well) are usually considered to be superior in this area. In the case of Certipur certification, the foam will also have been tested to some degree for durability and so is less likely to lose its beneficial qualities in a few months after purchase but the density of the memory foam would still be much more important durability factor than any limited durability testing done by CertiPur.
Without knowing what specifications and certifications the memory foam in your mattress has, I would not buy it. There are just too many retailers and manufacturers who are more than willing to provide you with this information which gives you the ability to make meaningful comparisons and make sure of the safety of your memory foam to waste any time with those who either can’t or won’t.
Some examples or different types of memory foams of different densities and different properties are in the videos here (with thanks to one of our manufacturing members Rocky Mountain Mattress).
While it’s not directly connected to the quality of memory foam itself because higher heat and humidity levels can speed up the softening and break down of any foam material . with more temperature sensitive materials like memory foam this can happen faster and so I would tend to avoid using memory foam with heated mattress pads or blankets or at the very least use them at the lowest setting and only for short periods of time. In some cases their use can also invalidate a warranty.
So there you have it. Hopefully I have covered the main points of the generic differences, strengths, and weaknesses of memory foam as a whole. In my experience and research, memory foam has been the subject of more misinformation and hype than almost any other material in a mattress and this confusion and misinformation has in my opinion led to too many poor or at least inappropriate mattress buying decisions. It is sometimes a frustrating process to "get to the bottom of things". Memory foam is certainly a valid choice in a mattress material for some people and there are many who love it however I believe that knowing more about what it does in comparison to other materials and why and how it does it, is an important part of buying a memory foam mattress. There are many choices of mattress construction available and the more those choices are based on fact, personal experience, and individual needs and personal preferences, the more likely you will be to buy a mattress that is perfect for YOU.