When checking out online customer reviews of crib mattresses - the traditional varieties made with polyurethane foam, fire retardants, and PVC/vinyl with phthalates, just to mention a few of the chemical components - it's clear that many parents think a crib mattress is safe simply because it's firm and fits snugly in the crib. While these are vital safety elements, many experts believe that to be truly safe, a crib mattress also has to be free of potentially toxic chemicals.

Generally, parents are not aware of the potentially dangerous chemicals in crib mattresses. Nor are they aware that the fumes from those chemicals can be emitted into the air your baby breathes for 12 to 15 hours every day.

In fact, the chemicals used in most crib mattresses, including some crib mattresses labeled 'organic' or 'natural,' have been linked to so many illnesses and other conditions that even retailers like Walmart are jumping on the bandwagon to reduce our exposure.

What are these dangerous chemicals?

* Vinyl / PVC: PVC requires plasticizers - chemical additives that make the waterproof cover soft and pliable. In addition to hormone disruptor chemicals known as phthalates, vinyl can also contain antimony fire retardants and antibacterial chemical treatments.

* Nylon, Damask or Polyurethane: Also used in the outside cover of mattresses, some of these coverings contain a polyurethane backing or a waterproof coating similar to Teflon®. They may also contain added fire retardants and antibacterial chemical treatments.

* Polyurethane Foam: A highly flammable petroleum product used as the primary material of many crib mattresses, polyurethane foam also usually contains fire retardant chemicals. These volatile organic compounds can break down into small particles which become airborne. Many "Eco", "Soy", "Bio" and "Plant Derived," crib mattresses also contain polyurethane foam. They are made with some natural materials, but the primary ingredient is still polyurethane foam.

* Natural Latex / Rubber or Coir: Natural latex/rubber has been linked to allergies, particularly in children. Most allergists recommend that babies and young children steer clear of latex. The situation is common enough that, according to the FDA, a product containing latex (particularly natural latex) cannot be labeled as "hypoallergenic." Coir (or coconut husks) also contains latex as a bonding agent. Many U.S. hospitals are in the process of removing materials and equipment that use latex.

* Wool, Mohair or Horsetail Hair: Wool is a natural fire retardant material used in many organic mattresses, but it can also be allergenic. Chemical treatments used to clean these fibers, remove dirt, sand, grease and dried sweat, can also be a problem.

* Fire Retardant Chemicals: PBDEs, which are being banned in products sold by Walmart, brominated or chlorinated fire retardants, antimony, modacrylic, polyacrylonitrile, respirable crystaline silica, boric acid and many other fire retardant chemicals are commonly found in crib mattresses.

Many of these chemicals have already been banned in other countries based on scientific evidence of their potential dangers. However, very few have been restricted in the U.S. This is largely because, in the U.S., the process of regulating chemicals is so difficult. Phthalates, for example, which have been banned in Europe for over a decade, were only recently banned in the U.S. And that was only a few of them. Many are still in use.

If you don't want to take chances with your little ones, get an organic crib mattress made with materials you don't have to worry will endanger your baby's health.

When selecting a crib mattress, many first time parents are concerned with finding the right size or shape and whether it looks and feels comfortable. Another important factor is whether or not the mattress meets fire safety standards. Fire retardant crib mattresses are important, but reading the label to see what chemicals are used in the production could save your baby's health and well being. The following list of chemicals should be avoided if at all possible.

Polybrominated diphenylethers or (PBDEs), are used in many of today's crib mattresses as a flame retardant. While having a PBDE flame retardant mattress may sound comforting at first, studies have concluded that the use of these chemicals in crib mattresses can cause liver and thyroid toxicity as well as neurodevelopment disorders. Even worse, these chemicals can accumulate in the body and be transferred through breast milk.

Brominated or Chlorinated hydrocarbons, used in crib mattresses to meet fire safety standards, can lead to DNA mutations and have been shown to cause cancer and birth defects in animals. Furthermore, these compounds can lead to endocrine and thyroid disorders.

Antimony is another chemical to look out for. While the element has been shown to extinguish itself during a fire, it holds chemical properties similar to arsenic and is just as poisonous. Side effects of Antimony poisoning include headaches, dizziness, and nausea and in larger doses can cause vomiting and death.

Dimethyl Sulfate is a carcinogen that that can be harmful if inhaled or absorbed through the skin.

Finally, Boric Acid and Crystalline Silica, are both used to treat the cotton batting found in crib mattresses to pass the cigarette ignition test. However, both have a history of being dangerous if inhaled leading to a variety of respiratory ailments and premature death.

To keep your baby safe, look for crib mattresses that use natural flame retardants such as baking soda or hydrated silica bonded to cellulose fiber. Both Baking Soda and Silica are natural, safe, non-toxic, and environmentally friendly ways to meet fire safety standards without the risk of poisoning your baby. Make sure the mattress has undergone strict testing to prove it does not give off harmful gasses. Finally, avoid crib mattresses that use Polyurethane foam as filler, which is a flammable, oil based, petroleum product that is essentially a solid form of gasoline. Following these guidelines will ensure a safe and healthy nights rest for your baby.