Is it worth it to buy an organic crib mattress for our baby?

Your child will spend a lot of time sleeping in that crib, so it's worth thinking about what's in the mattress. Many conventional mattresses are made of petroleum based chemicals, requiring large amount of flame retardant chemicals, and have plastic polyvinyl chloride (PVC) plastic mattress covers. All of these things should be avoided.  
 
The manufacture and disposal of PVC releases cancer-causing dioxins into the environment but in your nursery environment you might be more concerned about phthalates, which are often used in PVC. Phthalates interfere with testosterone and can cause abnormalities in male reproductive development. California recently banned the use of phthalates in products intended for children under the age of three. Avoid buying a mattress with a PVC plastic covering.  
 
Mattresses made from petroleum based chemicals, such as polyurethane foam, are highly flammable and require the addition of flame retardant chemicals to make them flame resistant. In the past, the most commonly used flame retardants were PBDEs (polybrominated diphenyl ethers). PBDEs were banned in Europe and then many states in the United States after they were found to be accumulating in blood and breast milk and were found to interfere with thyroid hormone and thereby affect brain development. Although these toxic chemicals have been banned and are no longer used, mattresses and other foam furniture must still meet stringent flame resistant standards in the United States. When you purchase a new mattress it isn�t likely contain PBDEs, but it might have other chemicals such as chlorinated-TRIS, a cancer-causing flame retardant chemical that was banned in children�s sleepwear decades ago but is now making a comeback. Manufacturers won�t tell you which chemicals they use as flame retardants because they consider it a trade secret.  
 
Mattresses made from natural materials, such as cotton or wool, must still meet flame resistant standards but because these materials are more inherently flame resistant, they require the addition of fewer chemicals. A mattress made from "organic" cotton or wool is grown without pesticides and is better for the environment.  
 
You should choose natural products for where you think your baby will spend the most time. Older baby furniture will release less toxic gases over time and may be better AND cheaper than new furniture. So splurge on a crib mattress made from natural materials, whether organic or not, and put it in a second-hand crib.