Mattress Material focus: Latex
Latex is a soft, yet durable material derived from the sap of the rubber tree. It is considered one of the highest quality mattress components when it is in its purest form due to its natural qualities of resiliency, comfort and natural spinal alignment. The latex used in mattresses is usually a blended composite of natural latex and synthetic latex, which is made of petroleum-based plasticizers and other petrochemicals. Mattresses that do not contain any synthetic materials, pesticides, herbicides or other manmade components are considered 100% organic and can be classified as such by the U.S. Department of Agriculture (USDA). This label is different from 100% natural latex, which may contain a small percentage of synthetic ingredients. The amount of natural/synthetic latex found in a mattress often times correlates with the price, overall quality, and warranty length. Models with higher amounts of natural latex are more resilient and comfortable for sleeping, and thus tend to be more expensive. Natural latex can be processed in two ways creating either Dunlop or Talalay natural latex layers.
Requires the rubber tree sap to be stirred, molded and steam-baked, causing natural sediment to collect at the bottom. The result is latex that is dense, heavier and sturdier.
This process involves placing the molded sap in a vacuum-sealed chamber, where it is deprived of air, frozen and finally baked. Compared to Dunlop foams, Talalay latex has a more homogenous consistency, making it softer and bouncier.
Impression Load Deflection (ILD)
You can test the softness or firmness of a latex mattress by measuring the impression load deflection. To measure ILD, set a circular metal disk with a 1-foot diameter onto a section of latex that is roughly four inches thick. The ILD measurement will be the amount of load (weight) or force needed to compress the foam by 25%. ILD ratings range from ‘firm’ (high) to ‘soft’ (low) and are expressed in numerical measurements.
ILD should not be confused with mattress density, which is an object’s mass divided by its volume; density measures mattress foam qualities like durability and support and is typically used to evaluate polyfoam mattresses.
Generally, Talalay latex will usually have a lower ILD rating than Dunlop foam. Here are some ranges you should familiarize yourself with if you are interested in what firmness you would like your latex mattress to be at.
- Softer latex mattresses range from 19-21 ILD, making it sink considerably under most sleepers
- Medium ILD is from 24-26, providing a balance of softness and firmness
- Medium-firm has an ILD of 29-31 with little sinking if any
- Firm is anything over 34ILD and does not provide any sinking
Latex is considered a high-quality comfort layer material because it will conform around your hips, shoulders, and contours. This alleviates pressure points and supports your spinal alignment. This is especially beneficial for people with chronic back and joint pain, as well as side sleepers, who need more cushioning in their midsection. And due to the natural durability of latex, the material will offer proper support and comfort for years ― more than a decade, in some cases. In latex with a low ILD, you may need to continually rotate the mattress in order to restore your sleep surface to its original shape.
This term (also called motion transfer) refers to how much movement can be detected from one side of the mattress to the other. If your partner tosses and turns in their sleep, then sleeping on a mattress designed for motion isolation means you won’t be able to feel their movement from your side of the bed.
Some mattress materials are prone to off-gassing, a reaction that occurs after the breakdown of substances called volatile organic compounds, or VOCs. Off-gassing produces a pungent, often unpleasant odor. Synthetic latex is known to produce some off-gassing, while organic and natural latex produce little to no off-gassing. Due to the low VOC levels, natural latex often receives green certification from third-party eco-labels like Oeko-Tex 100 and Eco Institut, as well as industry-oriented eco-labels like CertiPUR-US® certification.
Many report that latex sleeps hot, causing discomfort during the night―although natural and organic latex is considered more breathable.
Mattresses with latex comfort layers tend to carry the heftiest price tags. Expect to pay at least $900 to $1,200, although the average latex model will cost roughly $2,000.
Things to consider
If you are interested in buying a mattress with a latex comfort layer, here are a few questions to ask before finalizing your purchase:
What is the ratio of natural to synthetic latex?
- The amount of natural latex will usually dictate the comfort, lifespan, and price of the mattress. The ratio also indicates the likeliness of off-gassing, since organic and natural latex causes less off-gassing than synthetic latex.
Which process was used to produce the latex?
- The Dunlop process will produce a heavier and firmer comfort layer, while the Talalay process will yield a softer comfort layer.
What is the ILD rating?
- Remember: the higher the ILD, the firmer the mattress.