Published originally 11/27/2012:
We received a phone call recently from a gentleman who was frustrated with his latex research. I informed him that “There’s natural latex, and then there’s synthetic latex.” His reply was, “Well, but latex is latex is latex, right?”
The answer is absolutely not. As a matter of fact, there is a world of difference between natural latex and synthetic/polyurethane foam. To make things even more interesting and/or confusing, there are different variations of both kinds.
Natural latex is manufactured from sap tapped from rubber trees, then it is either vulcanized (Dunlop method) or frozen, then vulcanized (Talalay method.) I don't want to get too involved in which method is better, because it's hugely dependent upon the processing facility and a number of other factors.
The point is, natural latex is an incredibly resilient and durable, clean and supportive material. It is resistant to dust mites, anti-microbial, antifungal, and hypo-allergenic.
The important thing to remember when considering a product made of natural latex is purity - what is the percentage of pure natural latex vs fillers or synthetic material. Look for certification by an independent laboratory such as Oeko-Tex, which tests for chemicals and toxins in the finished product. The Oeko-Tex stamp of approval will attest to the cleanliness and purity of the product.
Some manufacturers add fillers (most commonly clays, calcium oxide, or titanium dioxide) to the natural latex to make it go further (imagine taking one gallon of milk and diluting it with water to create two gallons of milk). While the finished product will be less expensive, the addition of fillers ultimately makes the latex less durable and more apt to rapid breakdown. Here’s where the consumer needs to be very vigilant…the fact is that natural latex with additives such as those listed above can technically still be called “natural latex”.
Synthetic latex (aka polyurethane foam/memory foam) is made of petroleum by-products, sometimes actually mixed with natural latex.
Again, that's where you have to be careful. There are many manufacturers who tout their product as “natural latex”, when in fact it's actually a blend of natural AND synthetic. Interestingly, Dunlop and Talalay latex can be either natural or synthetic. Needless to say, Caveat emptor -- do your research.
Synthetic latex, being chemically based, has a tendency to break down more quickly than natural latex. If you've ever had a warranty issue with a mattress, you'll understand immediately. Have you ever had a body impression in your mattress measured by your friendly local mattress salesman and told that it's “normal wear and tear?”
Polyurethane foam /synthetic latex are actually graded on how quickly they're expected to break down. That's the reason you have to wait until the body impression is at least 1.5 inches (in most cases) in depth to get your warranty to be considered valid.
Synthetic latex / polyurethanes also have a tendency to off-gas. That is, the chemicals inside the mattress will escape and cause an odor. Here's a disturbing fact: you're breathing those chemicals in while your skin is absorbing them. There's also an issue with synthetics being unable to absorb and release moisture properly, trapping moisture and heat, which is a great breeding ground for molds, mildews, dust mites and other undesirable little critters.
What does that mean for you? Well, it means that the mattress made with poly-foam or synthetic latex is less durable: compacting or developing body impressions when confronted with weight and moisture (by the way, the human body emits about 1 liter of body moisture while sleeping. Not only sweat, but also moisture being released by the body through respiration. No kidding.)
Take this into consideration also: the average queen-sized polyurethane foam mattress covered in polyester fabric loses HALF its weight over ten years of use. Where does the weight go?
Polyurethane foam oxidizes, creates “fluff” (dust) which is released into the air and eventually settles in and around your home as well as in your lungs. Yes, you breathe in this dust. And some of the chemicals used in these types of mattresses include formaldehyde, styrene, toluene di-isocyanate (TDI), antimony...the list goes on and on. Once again, do your research if you're concerned about these things. We suggest reading up on the effects of chemicals on www.epa.gov.
The bottom line is that 100% natural latex (without fillers) is more resilient/durable, cleaner/healthier and more comfortable -- anti-microbial, anti-fungal,and hypo-allergenic, as well as being dust mite resistant and biodegradable. You'll pay a bit more for anything made of pure 100% natural latex, because it's more expensive to obtain and produce, but you get your money’s worth out of the product in longevity and comfort.
When purchasing a natural latex bed, remember this excellent advice: “If it seems too good to be true, it probably is.” A natural latex bed free of fillers won’t be inexpensive. Find out what warranty corresponds to the item you’re interested in, and read it thoroughly. The warranty will tell you a great deal. Also, keep in mind that websites can be tricky: many that have the Oeko Tex logo do have some natural latex products, but also polyurethane.
And there you have it, a crash-course in latex foam. Hope that helps you navigate the mattress world. Good luck & happy shopping.
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