Wednesday, January 21, 2009

Buying a mattress

What is Off-Gassing?
There are many different types of foams and batting materials used in mattresses these days; furthermore, there are many types of mattresses. If you go shopping you will undoubtedly encounter latex mattresses, memory foam mattresses, air mattresses (think Select Comfort calling itself the Sleep Number bed), innerspring coil mattresses, and futon mattresses.
Chemicals used in synthetic foams (mostly petroleum based) and some fire retarding agents emit fumes. Mattresses made using these chemicals can potentially cause reactions in people with chemical sensitivities. Some of these chemicals have not been tested on young children or in the proximity that is present in a mattress slept on for 8 hours a day. People with concerns about off-gassing would be well served knowing what is in the mattress they have or wish to purchase.
Here is how mattresses are made:
1. A memory foam mattress is not all memory foam. It is likely to be 5-6” of standard polyurethane foam topped with a visco-elastic layer, an open celled, slow recovery, poly foam . Both types of foam in these beds will off-gas . The odor coming off of these foams is from chemicals used in the process of making it. The chemicals emitted are potentially harmful to small children (www.gemtesting.com/naturepedic/P1.php) and people sensitive to such emissions may wish to select a different type of mattress.
2. A coil (innerspring) mattress can be made of several different components, and even different types of coils. Whether it be a pocketed coil, a continuous coil system, or any other type of coil, there will be an insulator pad between the coils and the comfort layers above. This insulator pad may be made from a high density polyurethane foam or recycled fabric layers (think carpet pad). On top of the insulator will be comfort layers used to give plushness. These comfort layers are mostly what differentiate mattresses. In most major brand mattresses these layers are polyurethane foams and therefore can off-gas. Many manufacturers, in an effort to be more “green”, are using some soy (can also be non-soy vegetable base) foams. Because soy foams only use about 20% soy oil and the rest is petroleum based, it does not eliminate the off-gassing, but it is a step in the right direction for people wishing to be “greener” and not chemically sensitive.
Wrapped around the mattress (all around in the case of two-sided, flip-able mattresses) is the quilting layer that gives the mattresses the finished look you expect. The puff in the quilt is usually polyurethane foam even in mattresses represented as natural.
An innerspring mattress can be made natural and non off-gassing with the use of a natural insulator, latex, wool and/or cotton comfort layers, and a quilt layer containing one of the same fillers.
3. A latex mattress should start with a solid latex core (sometimes manufacturers will mix layers of latex with other, less expensive layers). Latex comes in several varieties. There are different processes for creating latex. By definition latex is sap from a rubber tree, however there is also synthetic latex created in a lab with building blocks. Although synthesized latex may use polymers, there is little off-gassing and is likely to be a better choice than polyurethane.
Pure natural rubber latex comes from rubber trees grown near the equator. The process of extracting the liquid latex is much like tapping maple trees for syrup. Managed rubber tree forests make for a sustainable product. The molding of the latex cores can be accomplished with no added chemicals. Potentially allergenic proteins are at this point washed out in the cleansing process. With no chemicals to off-gas, pure latex mattresses are the best choice for healthy sleep. It is durable, comfortable and can be processed in different densities.
This is not the whole story however; just as memory foam mattresses are not all memory foam, latex mattresses are not always just latex. Comfort layers added will often be the same as used on innerspring mattresses and all the same cautions apply.
4. Air beds use vinyl or polyurethane bladders in place of innersprings or foam cores. The air chambers are protected by polyurethane foam, and are often topped with it as a comfort layer. It would be possible to make an airbed with comfort layers of wool, latex or cotton that would eliminate much of the off-gassing potential, however, we are unaware of any company producing such a mattress.
5. Futon mattresses are also an option. Most of them are going to have synthetic foams these days, and a synthetic fire barrier, but a non-off-gassing mattress can be done. You would want one with no polyurethane foam layers, and wool as the fire barrier. It is also possible to get latex layered with the other batting materials to make it more durable. As a rule, futon mattresses tend to matt and get pretty hard. Cotton is a cheap nontoxic batting material, but it is not ideal for a sleep surface.
Good choices of non off-gassing mattresses:
There are some good choices for non off-gassing mattresses, however, the information available from some retailers and salespeople is likely to be confusing and sometimes misleading. Prices are comparable to other better quality mattresses and you have the peace of mind knowing you are not being exposed daily to potentially unhealthy fumes.
Englander makes a limited line of natural beds and gives you the most bed dollar for dollar. Six Englander mattresses are particularly of note as having the least potential for off-gassing.
Natura makes some of the most popular and comfortably plush mattresses, many of them natural and non-off-gassing. Several also happen to be organic.
For overall purity, and commitment to non-toxic products, Organic Mattresses Incorporated (OMI) is a leader in non-off-gassing bedding. The purity of materials used and their handling is second to none. All of their products are listed as organic.
A little time spent researching construction materials can pay dividends when searching for the lowest chemical emission mattresses.

1 comment:

Unknown said...

Thanks for sharing this great piece of information. Do keep us update with some more updates. I love your blog very much. I have found it really useful.
Regards
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Arihant.